API

SpiceCharCell(size, length)

Create a SpiceCharCell that can contain up to size strings with length characters.

SpiceDoubleCell(size)

Create a SpiceDoubleCell that can contain up to size elements.

SpiceIntCell(size)

Create a SpiceIntCell that can contain up to size elements.

append!(cell, collection)

Append all items from collection to the char/double/integer SpiceCell cell.

copy(cell::SpiceCell)

Duplicate the SpiceCell cell.

diff(a::T, b::T) where T <: SpiceCell

Compute the difference of two sets of any data type to form a third set.

Arguments

• a: First input set
• b: Second input set

Output

Returns a cell containing the difference of a and b.

References

• NAIF Documentation

length(cell)

Returns the cardinality (number of elements) of cell.

push!(cell, items...)

Insert one or more items at the end of the char/double/integer SpiceCell cell.

union(a::T, b::T) where T <: SpiceCell

Compute the union of two sets of any data type to form a third set.

Arguments

• a: First input set
• b: Second input set

Output

Returns a cell containing the union of a and b.

References

• NAIF Documentation

appnd(item, cell)

Append an item to the char/double/integer SpiceCell cell.

References

• appndc - NAIF Documentation
• appndd - NAIF Documentation
• appndi - NAIF Documentation

axisar(axis, angle)

Construct a rotation matrix that rotates vectors by a specified angle about a specified axis.

Arguments

• axis: Rotation axis
• angle: Rotation angle in radians

Output

Rotation matrix corresponding to axis and angle

References

• NAIF Documentation

b1900()

Returns the Julian Date corresponding to Besselian date 1900.0.

References

• NAIF Documentation

b1950()

Returns the Julian Date corresponding to Besselian date 1950.0.

References

• NAIF Documentation

badkpv(caller, name, comp, size, divby, typ)

Determine if a kernel pool variable is present and if so that it has the correct size and type.

Arguments

• caller: Name of the routine calling this routine
• name: Name of a kernel pool variable
• comp: Comparison operator
• size: Expected size of the kernel pool variable
• divby: A divisor of the size of the kernel pool variable
• type: Expected type of the kernel pool variable

Output

The function returns false if the kernel pool variable is OK otherwise an exception is thrown.

References

• NAIF Documentation

bltfrm(frmcls)

Return a SPICE set containing the frame IDs of all built-in frames of a specified class.

Arguments

• frmcls: Frame class

Output

• idset: Set of ID codes of frames of the specified class

References

• NAIF Documentation

bodc2n(code)

Translate the SPICE integer code of a body into a common name for that body.

Arguments

• code: Integer ID code to be translated into a name

Output

A common name for the body identified by code or nothing if none was found.

References

• NAIF Documentation

bodc2s(code)

Translate a body ID code to either the corresponding name or if no name to ID code mapping exists, the string representation of the body ID value.

Arguments

• code: Integer ID code to translate to a string

Output

Returns a string corresponding to code

References

• NAIF Documentation

boddef(name, code)

Define a body name/ID code pair for later translation via bodn2c or bodc2n.

Arguments

• name: Common name of some body
• code: Integer code for that body

References

• NAIF Documentation

bodfnd(body, item)

Determine whether values exist for some item for any body in the kernel pool.

Arguments

• body: ID code of body
• item: Item to find ("RADII", "NUTAMPRA", etc.)

Output

Returns true if the item is in the kernel pool and false if it is not.

References

• NAIF Documentation

bodn2c(name)

Translate the name of a body or object to the corresponding SPICE integer ID code.

Arguments

• name: Body name to be translated into a SPICE ID code

Output

Return the SPICE integer ID code for the named body or nothing if none was found.

References

• NAIF Documentation

bods2c(name)

Translate a string containing a body name or ID code to an integer code.

Arguments

• name: String to be translated to an ID code

Output

Retunrs the integer ID code corresponding to name or nothing if none as found.

References

• NAIF Documentation

bodvcd(bodyid, item)

Fetch from the kernel pool the double precision values of an item associated with a body, where the body is specified by an integer ID code.

Arguments

• bodyid: Body ID code
• item: Item for which values are desired. ("RADII", "NUT_PREC_ANGLES", etc.)
• maxn: Maximum number of values that may be returned (default: 100)

Output

Returns the requested values.

References

• NAIF Documentation

bodvrd(bodynm, item)

Fetch from the kernel pool the double precision values of an item associated with a body.

Arguments

• bodynm: Body name
• item: Item for which values are desired. ("RADII", "NUT_PREC_ANGLES", etc.)
• maxn: Maximum number of values that may be returned (default: 100)

Output

• values: Values

References

• NAIF Documentation

brcktd(number, e1, e2)

brckti(number, e1, e2)

bschoc(value, array, order)

bschoi(value, array, order)

bsrchc(value, array)

bsrchd(value, array)

bsrchi(value, array)

card(cell)

Returns the cardinality (number of elements) of cell.

ccifrm(frclss, clssid)

Return the frame name, frame ID, and center associated with a given frame class and class ID.

Arguments

• frclss: Class of frame
• clssid: Class ID of frame

Output

Returns nothing if no frame was found or

• frcode: ID code of the frame
• frname: Name of the frame
• center: ID code of the center of the frame

References

• NAIF Documentation

cgv2el(center, vec1, vec2)

Form an ellipse from a center vector and two generating vectors.

Arguments

• center: Center vector
• vec1: Generating vector
• vec2: Generating vector

Output

Returns the ellipse defined by the input vectors.

References

• NAIF Documentation

chbder(cp, x2s, x, nderiv)

Given the coefficients for the Chebyshev expansion of a polynomial, this returns the value of the polynomial and its first nderiv derivatives evaluated at the input x.

Arguments

• cp: Chebyshev polynomial coefficients
• x2s: Transformation parameters of polynomial
• x: Value for which the polynomial is to be evaluated
• nderiv: The number of derivatives to compute

Output

Returns the derivatives of the polynomial.

References

• NAIF Documentation

cidfrm(cent)

Retrieve frame ID code and name to associate with a frame center.

Arguments

• cent: ID code for an object for which there is a preferred reference frame

Output

Returns nothing if no frame was found or

• frcode: The ID code of the frame associated with cent
• frname: The name of the frame with ID frcode

References

• NAIF Documentation

ckcls(handle)

Close an open CK file.

Arguments

• handle: Handle of the CK file to be closed

References

• NAIF Documentation

ckcov!(ck, idcode, needav, level, tol, timsys, cover)

Find the coverage window for a specified object in a specified CK file.

Arguments

• ck: Name of CK file
• idcode: ID code of object
• needav: Flag indicating whether angular velocity is needed
• level: Coverage level: "SEGMENT" OR "INTERVAL"
• tol: Tolerance in ticks
• timsys: Time system used to represent coverage
• cover: Window giving coverage for idcode. Data already present in cover will be combined with coverage found for the object designated by idcode in the file ck.

References

• NAIF Documentation

ckcov(ck, idcode, needav, level, tol, timsys)

Find the coverage window for a specified object in a specified CK file.

Arguments

• ck: Name of CK file
• idcode: ID code of object
• needav: Flag indicating whether angular velocity is needed
• level: Coverage level: "SEGMENT" OR "INTERVAL"
• tol: Tolerance in ticks
• timsys: Time system used to represent coverage

Output

Window giving coverage for idcode

References

• NAIF Documentation

ckgp(inst, sclkdp, tol, ref)

Get pointing (attitude) for a specified spacecraft clock time.

Arguments

• inst: NAIF ID of instrument, spacecraft, or structure
• sclkdp: Encoded spacecraft clock time
• tol: Time tolerance
• ref: Reference frame

Outputs

Returns nothing if the requested pointing is not available or

• cmat: C-matrix pointing data
• clkout: Output encoded spacecraft clock time

References

• NAIF Documentation

ckgpav(inst, sclkdp, tol, ref)

Get pointing (attitude) and angular velocity for a specified spacecraft clock time.

Arguments

• inst: NAIF ID of instrument, spacecraft, or structure
• sclkdp: Encoded spacecraft clock time
• tol: Time tolerance
• ref: Reference frame

Outputs

Returns nothing if the requested pointing is not available or

• cmat: C-matrix pointing data
• av: Angular velocity vector
• clkout: Output encoded spacecraft clock time

References

• NAIF Documentation

cklpf(filename)

Load a CK pointing file for use by the CK readers. Return that file's handle, to be used by other CK routines to refer to the file.

Arguments

• filename: Name of the CK file to be loaded

Output

Loaded file's handle

References

• NAIF Documentation

ckobj!(ck, ids)

Find the set of ID codes of all objects in a specified CK file.

Arguments

• ck: Name of CK file
• ids: Set of ID codes of objects in CK file. Data already present in ids will be combined with ID code set found for the file ck.

References

• NAIF Documentation

ckobj(ck)

Find the set of ID codes of all objects in a specified CK file.

Arguments

• ck: Name of CK file

Output

Set of ID codes of objects in CK file.

References

• NAIF Documentation

ckopn(fname, ifname="CK_file", ncomch=0)

Open a new CK file, returning the handle of the opened file.

Arguments

• fname: The name of the CK file to be opened
• ifname: The internal filename for the CK (default: "CK_file")
• ncomch: The number of characters to reserve for comments (default: 0)

Output

• handle: The handle of the opened CK file

References

• NAIF Documentation

ckupf(handle)

Unload a CK pointing file so that it will no longer be searched by the readers.

Arguments

• handle: Handle of CK file to be unloaded

References

• NAIF Documentation

ckw01(handle, begtim, endtim, inst, ref, segid, sclkdp, quats, avvs=[zeros(3)])

Add a type 1 segment to a C-kernel.

Arguments

• handle: Handle of an open CK file
• begtim: The beginning encoded SCLK of the segment
• endtim: The ending encoded SCLK of the segment
• inst: The NAIF instrument ID code
• ref: The reference frame of the segment
• segid: Segment identifier
• sclkdp: Encoded SCLK times
• quats: Quaternions representing instrument pointing
• avvs: Angular velocity vectors (optional)

References

• NAIF Documentation

ckw02(handle, begtim, endtim, inst, ref, segid, start, stop, quats, avvs, rates)

Write a type 2 segment to a C-kernel.

Arguments

• handle: Handle of an open CK file
• begtim: The beginning encoded SCLK of the segment
• endtim: The ending encoded SCLK of the segment
• inst: The NAIF instrument ID code
• ref: The reference frame of the segment
• segid: Segment identifier
• start: Encoded SCLK interval start times
• stop: Encoded SCLK interval stop times
• quats: Quaternions representing instrument pointing
• avvs: Angular velocity vectors
• rates: Number of seconds per tick for each interval

References

• NAIF Documentation

ckw03(handle, begtim, endtim, inst, ref, segid, sclkdp, quats, starts, avvs=[zeros(3)])

Add a type 3 segment to a C-kernel.

Arguments

• handle: Handle of an open CK file
• begtim: The beginning encoded SCLK of the segment
• endtim: The ending encoded SCLK of the segment
• inst: The NAIF instrument ID code
• ref: The reference frame of the segment
• segid: Segment identifier
• sclkdp: Encoded SCLK times
• quats: Quaternions representing instrument pointing
• starts: Encoded SCLK interval start times
• avvs: Angular velocity vectors (optional)

References

• NAIF Documentation

ckw05(handle, subtyp, degree, begtim, endtim, inst, ref, avflag, segid, sclkdp, packts,
      rate, nints, starts)

Write a type 5 segment to a CK file.

Arguments

• handle: Handle of an open CK file
• subtyp: CK type 5 subtype code
• degree: Degree of interpolating polynomials
• begtim: The beginning encoded SCLK of the segment
• endtim: The ending encoded SCLK of the segment
• inst: The NAIF instrument ID code
• ref: The reference frame of the segment
• avflag: True if the segment will contain angular velocity
• segid: Segment identifier
• sclkdp: Encoded SCLK times
• packts: Array of packets
• rate: Nominal SCLK rate in seconds per tick
• nints: Number of intervals
• starts: Encoded SCLK interval start times

References

• NAIF Documentation

cleard(array)

clight()

Returns the speed of light in vacuo (km/sec).

References

• NAIF Documentation

clpool()

Remove all variables from the kernel pool. Watches on kernel variables are retained.

References

• NAIF Documentation

cmprss(delim, n, input)

Compress a character string by removing occurrences of more than n consecutive occurrences of a specified character.

Arguments

• delim: Delimiter to be compressed
• n: Maximum consecutive occurrences of delim
• input: Input string

Output

Returns the compressed string.

References

• NAIF Documentation

cnmfrm(cname)

Retrieve frame ID code and name to associate with an object.

Arguments

• cname: Name of the object to find a frame for

Output

Returns a tuple of the ID code and the name of the frame associated with cname or nothing if no frame is found.

References

• NAIF Documentation

conics(elts, et)

Determine the state (position, velocity) of an orbiting body from a set of elliptic, hyperbolic, or parabolic orbital elements.

Arguments

• elts: Conic elements
• et: Input time

Output

Returns the state of orbiting body at et.

References

• NAIF Documentation

convrt(x, in, out)

Take a measurement x, the units associated with x, and units to which x should be converted; return y - the value of the measurement in the output units.

Arguments

• x: Number representing a measurement in some units
• in: The units in which x is measured
• out: Desired units for the measurement

Output

Returns the measurement in the desired units.

References

• NAIF Documentation

cpos(str, chars, start)

Find the first occurrence in a string of a character belonging to a collection of characters, starting at a specified location, searching forward.

Arguments

• str: Any character string
• chars: A collection of characters
• start: Position to begin looking for one of chars

Output

Returns the index of the first character of str that is one of the characters in string chars. Returns -1 if none of the characters was found.

References

• NAIF Documentation

cposr(str, chars, start)

Find the first occurrence in a string of a character belonging to a collection of characters, starting at a specified location, searching in reverse.

Arguments

• str: Any character string
• chars: A collection of characters
• start: Position to begin looking for one of chars

Output

Returns the index of the last character of str that is one of the characters in string chars. Returns -1 if none of the characters was found.

References

• NAIF Documentation

cvpool(agent)

Indicate whether or not any watched kernel variables that have a specified agent on their notification list have been updated.

Arguments

• agent: Name of the agent to check for notices

Output

Returns true if variables for agent have been updated.

References

• NAIF Documentation

cyllat(r, lonc, z)

Convert from cylindrical to latitudinal coordinates.

Arguments

• r: Distance of point from z axis
• lonc: Cylindrical angle of point from XZ plane (radians)
• z: Height of point above XY plane

Output

• radius: Radius
• lon: Longitude (radians)
• lat: Latitude (radians)

References

• NAIF Documentation

cylrec(r, lon, z)

Convert from cylindrical to rectangular coordinates.

Arguments

• r: Distance of the point of interest from z axis
• lon: Cylindrical angle (in radians) of the point of interest from XZ plane
• z: Height of the point above XY plane

Output

Returns rectangular coordinates of the point of interest.

References

• NAIF Documentation

cylsph(r, lonc, z)

Convert from cylindrical to spherical coordinates.

Arguments

• r: Distance of point from z axis
• lonc: Angle (radians) of point from XZ plane
• z: Height of point above XY plane

Output

• radius: Distance of the point from the origin
• colat: Polar angle (co-latitude in radians)
• lon: Azimuthal angle (longitude)

References

• NAIF Documentation

dafac(handle, buffer)

Add comments from a buffer of character strings to the comment area of a binary DAF file, appending them to any comments which are already present in the file's comment area.

Arguments

• handle: Handle of a DAF opened with write access
• buffer: Buffer of comments to put into the comment area

References

• NAIF Documentation

dafbbs(handle)

Begin a backward search for arrays in a DAF.

Arguments

• handle: Handle of DAF to be searched

References

• NAIF Documentation

dafbfs(handle)

Begin a forward search for arrays in a DAF.

Arguments

• handle: Handle of DAF to be searched

References

• NAIF Documentation

dafcls(handle)

Close the DAF associated with a given handle.

Arguments

• handle: Handle of DAF to be closed

Output

Returns the handle of the closed file.

References

• NAIF Documentation

dafcs(handle)

Select a DAF that already has a search in progress as the one to continue searching.

Arguments

• handle: Handle of DAF to continue searching

References

• NAIF Documentation

dafdc(handle)

Delete the entire comment area of a specified DAF file.

Arguments

• handle: The handle of a binary DAF opened for writing

References

• NAIF Documentation

dafec(handle; bufsiz=256, lenout=1024)

Extract comments from the comment area of a binary DAF.

Arguments

• handle: Handle of binary DAF opened with read access
• bufsiz: Maximum size, in lines, of buffer (default: 256)
• lenout: Length of strings in output buffer (default: 1024)

Output

Returns a buffer where extracted comment lines are placed.

References

• NAIF Documentation

daffna()

Find the next (forward) array in the current DAF.

Output

Returns true if an array was found.

References

• NAIF Documentation

daffpa()

Find the previous (backward) array in the current DAF.

Output

Returns true if an array was found.

References

• NAIF Documentation

dafgda(handle, start, stop)

Read the double precision data bounded by two addresses within a DAF.

Arguments

• handle: Handle of a DAF
• start, stop: Initial, final address within file

Output

Returns the data contained between start and stop.

References

• NAIF Documentation

dafgh()

Return (get) the handle of the DAF currently being searched.

References

• NAIF Documentation

dafgn(lenout=128)

Return (get) the name for the current array in the current DAF.

Arguments

• lenout: Length of array name string (default: 128)

Output

Returns the name of the current array.

References

• NAIF Documentation

dafgs(lenout=128)

Return (get) the summary for the current array in the current DAF.

Arguments

• lenout: The maximum length of the summary array

Output

Returns the summary for the current array.

References

• NAIF Documentation

Read a portion of the contents of a summary record in a DAF file.

Arguments

• handle: Handle of DAF
• recno: Record number
• start: First word to read from record
• stop: Last word to read from record

Output

Returns the contents of the record or nothing if none was found.

References

• NAIF Documentation

dafopr(fname)

Open a DAF for subsequent read requests.

Arguments

• fname: Name of DAF to be opened

Output

Returns the handle assigned to DAF.

References

• NAIF Documentation

dafopw(fname)

Open a DAF for subsequent write requests.

Arguments

• fname: Name of DAF to be opened

Output

Returns the handle assigned to DAF.

References

• NAIF Documentation

dafps(dc, ic)

Pack (assemble) an array summary from its double precision and integer components.

Arguments

• dc: Double precision components
• ic: Integer components

Output

Returns the array summary.

References

• NAIF Documentation

dafrfr(handle, lenout=128)

Read the contents of the file record of a DAF.

Arguments

• handle: Handle of an open DAF file
• lenout: Available room in the output string `ifname' (default: 128)

Output

• nd: Number of double precision components in summaries
• ni: Number of integer components in summaries
• ifname: Internal file name
• fward: Forward list pointer
• bward: Backward list pointer
• free: Free address pointer

References

• NAIF Documentation

dafrs(sum)

Change the summary for the current array in the current DAF.

Arguments

• sum: New summary for current array

References

• NAIF Documentation

dafus(sum, nd, ni)

Unpack an array summary into its double precision and integer components.

Arguments

• sum: Array summary
• nd: Number of double precision components
• ni: Number of integer components

Output

• dc: Double precision components
• ic: Integer components

References

• NAIF Documentation

dasac(handle, buffer)

Add comments from a buffer of character strings to the comment area of a binary DAS file, appending them to any comments which are already present in the file's comment area.

Arguments

• handle: Handle of a DAS opened with write access
• buffer: Buffer of comments to put into the comment area

References

• NAIF Documentation

dascls(handle)

Close the DAS associated with a given handle.

Arguments

• handle: Handle of DAS to be closed

Output

Returns the handle of the closed file.

References

• NAIF Documentation

dasdc(handle)

Delete the entire comment area of a specified DAS file.

Arguments

• handle: The handle of a binary DAS opened for writing

References

• NAIF Documentation

dasec(handle; bufsiz=256, lenout=1024)

Extract comments from the comment area of a binary DAS.

Arguments

• handle: Handle of binary DAS opened with read access
• bufsiz: Maximum size, in lines, of buffer (default: 256)
• lenout: Length of strings in output buffer (default: 1024)

Output

Returns a buffer where extracted comment lines are placed.

References

• NAIF Documentation

dashfn(handle, namelen=256)

Return the name of the DAS file associated with a handle.

Arguments

• handle: Handle of a DAS file
• namlen: Length of output file name string (default: 256)

Output

Returns the corresponding file name.

References

• NAIF Documentation

dasopr(fname)

Open a DAS for subsequent read requests.

Arguments

• fname: Name of DAS to be opened

Output

Returns the handle assigned to DAS.

References

• NAIF Documentation

dasopw(fname)

Open a DAS for subsequent write requests.

Arguments

• fname: Name of DAS to be opened

Output

Returns the handle assigned to DAS.

References

• NAIF Documentation

dasrfr(handle, idwlen=128, ifnlen=256)

Read the contents of the file record of a DAS.

Arguments

• handle: DAS file handle
• idwlen: Length of ID word string (default: 128)
• ifnlen: Length of internal file name string (default: 256)

Output

• idword: ID word
• ifname: DAS internal file name
• nresvr: Number of reserved records in file
• nresvc: Number of characters in use in reserved records area
• ncomr: Number of comment records in file
• ncomc: Number of characters in use in comment area

References

• NAIF Documentation

dcyldr(x, y, z)

Compute the Jacobian of the transformation from rectangular to cylindrical coordinates.

Arguments

• x: X-coordinate of point
• y: Y-coordinate of point
• z: Z-coordinate of point

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

deltet(epoch, eptype)

Return the value of ΔET (ET-UTC) for an input epoch.

Arguments

• epoch: Input epoch (seconds past J2000)
• eptype: Type of input epoch ("UTC" or "ET")

Output

Returns ΔET (ET-UTC) at input epoch.

References

• NAIF Documentation

dgeodr(x, y, z, re, f)

Compute the Jacobian of the transformation from rectangular to geodetic coordinates.

Arguments

• x: X-coordinate of point
• y: Y-coordinate of point
• z: Z-coordinate of point
• re: Equatorial radius of the reference spheroid
• f: Flattening coefficient

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

diags2(symmat)

Diagonalize a symmetric 2x2 matrix.

Arguments

• symmat: A symmetric 2x2 matrix

Output

• diag: A diagonal matrix similar to symmat
• rotate: A rotation used as the similarity transformation

References

• NAIF Documentation

dlabbs(handle)

Begin a backward segment search in a DLA file.

Arguments

• handle: Handle of open DLA file

Output

Returns the descriptor of the last segment in the DLA file or nothing if none was found.

References

• NAIF Documentation

dlabfs(handle)

Begin a forward segment search in a DLA file.

Arguments

• handle: Handle of open DLA file

Output

Returns the descriptor of the first segment in the DLA file or nothing if none was found.

References

• NAIF Documentation

dlafns(handle, descr)

Find the segment following a specified segment in a DLA file.

Arguments

• handle: Handle of open DLA file
• descr: Descriptor of a DLA segment

Output

Returns the descriptor of the next segment in the DLA file or nothing if none was found.

References

• NAIF Documentation

dlafps(handle, descr)

Find the segment preceding a specified segment in a DLA file.

Arguments

• handle: Handle of open DLA file
• descr: Descriptor of a DLA segment

Output

Returns the descriptor of the previous segment in the DLA file or nothing if none was found.

References

• NAIF Documentation

dlatdr(x, y, z)

Compute the Jacobian of the transformation from rectangular to latitudinal coordinates.

Arguments

• x: X-coordinate of point
• y: Y-coordinate of point
• z: Z-coordinate of point

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

dp2hx(number, lenout=128)

Convert a double precision number to an equivalent character string using base 16 "scientific notation."

Arguments

• number: Number to be converted
• lenout: Available space for output string

Output

Returns the equivalent character string, left justified.

References

• NAIF Documentation

dpgrdr(x, y, z, re, f)

Compute the Jacobian of the transformation from rectangular to planetographic coordinates.

Arguments

• body: Body with which coordinate system is associated
• x: X-coordinate of point
• y: Y-coordinate of point
• z: Z-coordinate of point
• re: Equatorial radius of the reference spheroid
• f: Flattening coefficient

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

dpmax()

dpmin()

dpr()

drdcyl(r, lon, z)

Compute the Jacobian of the transformation from cylindrical to rectangular coordinates.

Arguments

• r: Distance of a point from the origin
• lon: Angle of the point from the xz plane in radians
• z: Height of the point above the xy plane

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

drdgeo(lon, lat, alt, re, f)

Compute the Jacobian of the transformation from geodetic to rectangular coordinates.

Arguments

• lon: Geodetic longitude of point (radians)
• lat: Geodetic latitude of point (radians)
• alt: Altitude of point above the reference spheroid
• re: Equatorial radius of the reference spheroid
• f: Flattening coefficient

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

drdlat(radius, lon, lat)

Compute the Jacobian of the transformation from latitudinal to rectangular coordinates.

Arguments

• radius: Distance of a point from the origin
• lon: Angle of the point from the XZ plane in radians
• lat: Angle of the point from the XY plane in radians

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

drdpgr(body, lon, lat, alt, re, f)

Compute the Jacobian matrix of the transformation from planetographic to rectangular coordinates.

Arguments

• body: Name of body with which coordinates are associated
• lon: Planetographic longitude of a point (radians)
• lat: Planetographic latitude of a point (radians)
• alt: Altitude of a point above reference spheroid
• re: Equatorial radius of the reference spheroid
• f: Flattening coefficient

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

drdsph(r, colat, lon)

Compute the Jacobian of the transformation from latitudinal to rectangular coordinates.

Arguments

• r: Distance of a point from the origin
• colat: Angle of the point from the positive z-axis
• lon: Angle of the point from the xy plane

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

dskb02(handle, dladsc)

Return bookkeeping data from a DSK type 2 segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor

Output

• nv: Number of vertices in model
• np: Number of plates in model
• nvxtot: Number of voxels in fine grid
• vtxbds: Vertex bounds
• voxsiz: Fine voxel edge length
• voxori: Fine voxel grid origin
• vgrext: Fine voxel grid exent
• cgscal: Coarse voxel grid scale
• vtxnpl: Size of vertex-plate correspondence list
• voxnpt: Size of voxel-plate pointer list
• voxnpl: Size of voxel-plate correspondence list

References

• NAIF Documentation

dskcls(handle, optmiz=true)

Close a DSK file.

Arguments

• handle: Handle assigned to the opened DSK file
• optmiz: Flag indicating whether to segregate the DSK (default: true)

References

• NAIF Documentation

dskd02(handle, dladsc, item, start, room)

Fetch double precision data from a type 2 DSK segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor
• item: Keyword identifying item to fetch
• start: Start index
• room: Amount of room in output array

Output

Returns an array containing the requested item.

References

• NAIF Documentation

dskgd(handle, dladsc)

Return the DSK descriptor from a DSK segment identified by a DAS handle and DLA descriptor.

Arguments

• handle: Handle of a DSK file
• dladsc: DLA segment descriptor

Output

Returns the DSK segment descriptor.

References

• NAIF Documentation

dskgtl(keywrd)

Retrieve the value of a specified DSK tolerance or margin parameter.

Arguments

• keywrd: Code specifying parameter to retrieve

Output

Returns the value of the parameter.

References

• NAIF Documentation

dski02(handle, dladsc, item, start, room)

Fetch integer data from a type 2 DSK segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor
• item: Keyword identifying item to fetch
• start: Start index
• room: Amount of room in output array

Output

Returns an array containing the requested item.

References

• NAIF Documentation

dskmi2(vrtces, plates, finscl, corscl, worksz, voxpsz, voxlsz, makvtl, spaisz)

Make spatial index for a DSK type 2 segment.

Arguments

• vrtces: Vertices
• plates: Plates
• finscl: Fine voxel scale
• corscl: Coarse voxel scale
• worksz: Workspace size
• voxpsz: Voxel-plate pointer array size
• voxlsz: Voxel-plate list array size
• makvtl: Vertex-plate list flag
• spxisz: Spatial index integer component size

Output

• spaixd: Double precision component of spatial index.
• spaixi: Integer component of spatial index.

References

• NAIF Documentation

dskn02(handle, dladsc, plid)

Compute the unit normal vector for a specified plate from a type 2 DSK segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor
• plid: Plate ID

Output

Return the plate's unit normal vector.

References

• NAIF Documentation

dskobj!(set, dsk)

Find the set of body ID codes of all objects for which topographic data are provided in a specified DSK file.

Arguments

• dsk: Name of DSK file
• set or len: Either a preallocated SpiceIntCell or the size of the output set.

Output

Returns the set of ID codes of objects in the DSK file.

References

• NAIF Documentation

dskopn(fname, ifname, ncomch)

Open a new DSK file for subsequent write operations.

Arguments

• fname: Name of a DSK file to be opened
• ifname: Internal file name
• ncomch: Number of comment characters to allocate

Output

Returns the handle assigned to the opened DSK file.

References

• NAIF Documentation

dskp02(handle, dladsc, start, room)

Fetch triangular plates from a type 2 DSK segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor
• start: Start index
• room: Amount of room in output array

Output

Returns an array of plates.

References

• NAIF Documentation

dskrb2(vrtces, plates, corsys, corpar)

Determine range bounds for a set of triangular plates to be stored in a type 2 DSK segment.

Arguments

• vrtces: Vertices
• plates: Plates
• corsys: DSK coordinate system code
• corpar: DSK coordinate system parameters

Output

• mncor3: Lower bound on range of third coordinate
• mxcor3: Upper bound on range of third coordinate

References

• NAIF Documentation

dsksrf!(set, dsk)

Find the set of surface ID codes of all objects for which topographic data are provided in a specified DSK file.

Arguments

• dsk: Name of DSK file
• set or len: Either a preallocated SpiceIntCell or the size of the output set.

Output

Returns the set of ID codes of surfaces in the DSK file.

References

• NAIF Documentation

dskstl(keywrd)

Set the value of a specified DSK tolerance or margin parameter.

Arguments

• keywrd: Code specifying parameter to retrieve
• dpval: Value of parameter

References

• NAIF Documentation

dskv02(handle, dladsc, start, room)

Fetch vertices from a type 2 DSK segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor
• start: Start index
• room: Amount of room in output array

Output

Returns an array of vertices.

References

• NAIF Documentation

dskw02(handle, center, surfid, dclass, frame, corsys, corpar, mncor1, mxcor1,
       mncor2, mxcor2, mncor3, mxcor3, first, last, vrtces, plates, spaixd, spaixi)

Write a type 2 segment to a DSK file.

Arguments

• handle: Handle assigned to the opened DSK file
• center: Central body ID code
• surfid: Surface ID code
• dclass: Data class
• frame: Reference frame
• corsys: Coordinate system code
• corpar: Coordinate system parameters
• mncor1: Minimum value of first coordinate
• mxcor1: Maximum value of first coordinate
• mncor2: Minimum value of second coordinate
• mxcor2: Maximum value of second coordinate
• mncor3: Minimum value of third coordinate
• mxcor3: Maximum value of third coordinate
• first: Coverage start time
• last: Coverage stop time
• nv: Number of vertices
• vrtces: Vertices
• np: Number of plates
• plates: Plates
• spaixd: Double precision component of spatial index
• spaixi: Integer component of spatial index

References

• NAIF Documentation

dskx02(handle, dladsc, vertex, raydir)

Determine the plate ID and body-fixed coordinates of the intersection of a specified ray with the surface defined by a type 2 DSK plate model.

Arguments

• handle: Handle of DSK kernel containing plate model
• dladsc: DLA descriptor of plate model segment
• vertex: Ray vertex in the body fixed frame
• raydir: Ray direction in the body fixed frame

Output

Returns nothing if no intercept exists or

• plid: ID code of the plate intersected by the ray
• xpt: Intercept

References

• NAIF Documentation

dskxsi(pri, target, nsurf, srflst, et, fixref, vertex, raydir, maxd=1, maxi=1)

Compute a ray-surface intercept using data provided by multiple loaded DSK segments. Return information about the source of the data defining the surface on which the intercept was found: DSK handle, DLA and DSK descriptors, and DSK data type-dependent parameters.

Arguments

• pri: Data prioritization flag
• target: Target body name
• srflst: Surface ID list
• et: Epoch, expressed as seconds past J2000 TDB
• fixref: Name of target body-fixed reference frame
• vertex: Vertex of ray
• raydir: Direction vector of ray
• maxd: Size of DC array (default: 1)
• maxi: Size of IC array (default: 1)

Output

Returns nothing if no intercept exists or

• xpt: Intercept point
• handle: Handle of segment contributing surface data
• dladsc: DLA descriptor of segment
• dskdsc: DSK descriptor of segment
• dc: Double precision component of source info
• ic: Integer component of source info

References

• NAIF Documentation

dskxv(pri, target, srflst, et, fixref, nrays, vtxarr, dirarr)

Compute ray-surface intercepts for a set of rays, using data provided by multiple loaded DSK segments.

Arguments

• pri: Data prioritization flag
• target: Target body name
• srflst: Surface ID list
• et: Epoch, expressed as seconds past J2000 TDB
• fixref: Name of target body-fixed reference frame
• nrays: Number of rays
• vtxarr: Array of vertices of rays
• dirarr: Array of direction vectors of rays

Output

• xptarr: Intercept point array
• fndarr: Found flag array

References

• NAIF Documentation

dskz02(handle, dladsc)

Return plate model size parameters - plate count and vertex count - for a type 2 DSK segment.

Arguments

• handle: DSK file handle
• dladsc: DLA descriptor

Output

• nv: Number of vertices
• np: Number of plates

References

• NAIF Documentation

dsphdr(x, y, z)

Compute the Jacobian of the transformation from rectangular to spherical coordinates.

Arguments

• x: X-coordinate of point
• y: Y-coordinate of point
• z: Z-coordinate of point

Output

Returns the matrix of partial derivatives.

References

• NAIF Documentation

dtpool(name)

Return the data about a kernel pool variable.

Arguments

• name: Name of the variable whose value is to be returned

Output

Returns the tuple (n ,vartype).

• n: Number of values returned for name
• vartype: Type of the variable
  • :C if the data is character data
  • :N if the data is numeric
  • :X if there is no variable name in the pool

References

• NAIF Documentation

ducrss(s1, s2)

Compute the unit vector parallel to the cross product of two 3-dimensional vectors and the derivative of this unit vector.

Arguments

• s1: Left hand state for cross product and derivative
• s2: Right hand state for cross product and derivative

Output

Returns the unit vector and derivative of the cross product.

References

• NAIF Documentation

dvcrss(s1, s2)

Compute the cross product of two 3-dimensional vectors and the derivative of this cross product.

Arguments

• s1: Left hand state for cross product and derivative
• s2: Right hand state for cross product and derivative

Output

Returns the cross product and its derivative.

References

• NAIF Documentation

dvdot(s1, s2)

Compute the derivative of the dot product of two double precision position vectors.

Arguments

• s1: First state vector in the dot product
• s2: Second state vector in the dot product

Output

Returns the derivative of the dot product s1 ⋅ s2.

References

• NAIF Documentation

dvhat(s1)

Find the unit vector corresponding to a state vector and the derivative of the unit vector.

Arguments

• s1: State to be normalized

Output

Returns the unit vector s1 / |s1|, and its time derivative.

References

• NAIF Documentation

dvnorm(state)

Function to calculate the derivative of the norm of a 3-vector.

Arguments

• state: A 6-vector composed of three coordinates and their derivatives.

Output

Returns the derivative of the norm of state.

References

• NAIF Documentation

dvpool(name)

Delete a variable from the kernel pool.

Arguments

• name: Name of the kernel variable to be deleted

References

• NAIF Documentation

dvsep(s1, s2)

Calculate the time derivative of the separation angle between two input states, s1 and s2.

Arguments

• s1: State vector of the first body
• s2: State vector of the second body

Output

Returns the value of the time derivative of the angular separation between s1 and s2.

References

• NAIF Documentation

edlimb(a, b, c, viewpt)

Find the limb of a triaxial ellipsoid, viewed from a specified point.

Arguments

• a: Length of ellipsoid semi-axis lying on the x-axis
• b: Length of ellipsoid semi-axis lying on the y-axis
• c: Length of ellipsoid semi-axis lying on the z-axis
• viewpt: Location of viewing point

Output

Returns the limb of the ellipsoid as seen from the viewing point.

References

• NAIF Documentation

edterm(trmtyp, source, target, et, fixref, abcorr, obsrvr, npts)

Compute a set of points on the umbral or penumbral terminator of a specified target body, where the target shape is modeled as an ellipsoid.

Arguments

• trmtyp: Terminator type
• source: Light source
• target: Target body
• et: Observation epoch
• fixref: Body-fixed frame associated with target
• abcorr: Aberration correction
• obsrvr: Observer
• npts: Number of points in terminator set

Output

• trgepc: Epoch associated with target center
• obspos: Position of observer in body-fixed frame
• trmpts: Terminator point set

References

• NAIF Documentation

ekacec(handle, segno, recno, column, cvals, isnull)

Add data to a character column in a specified EK record.

Arguments

• handle: EK file handle
• segno: Index of segment containing record
• recno: Record to which data is to be added
• column: Column name
• cvals: Character values to add to column
• isnull: Flag indicating whether column entry is null

References

• NAIF Documentation

ekaced(handle, segno, recno, column, dvals, isnull)

Add data to an double precision column in a specified EK record.

Arguments

• handle: EK file handle
• segno: Index of segment containing record
• recno: Record to which data is to be added
• column: Column name
• dvals: Double precision values to add to column
• isnull: Flag indicating whether column entry is null

References

• NAIF Documentation

ekacei(handle, segno, recno, column, ivals, isnull)

Add data to an integer column in a specified EK record.

Arguments

• handle: EK file handle
• segno: Index of segment containing record
• recno: Record to which data is to be added
• column: Column name
• ivals: Integer values to add to column
• isnull: Flag indicating whether column entry is null

References

• NAIF Documentation

ekaclc(handle, segno, column, cvals, nlflgs, rcptrs)

Add an entire character column to an EK segment.

Arguments

• handle: EK file handle.
• segno: Number of segment to add column to.
• column: Column name.
• cvals: Character values to add to column.
• nlflgs: Array of null flags for column entries.
• rcptrs: Record pointers for segment.

References

• NAIF Documentation

ekacld(handle, segno, column, dvals, nlflgs, rcptrs)

Add an entire double precision column to an EK segment.

Arguments

• handle: EK file handle
• segno: Number of segment to add column to
• column: Column name
• dvals: Double precision values to add to column
• nlflgs: Array of null flags for column entries
• rcptrs: Record pointers for segment

References

• NAIF Documentation

ekacli(handle, segno, column, ivals, nlflgs, rcptrs)

Add an entire integer column to an EK segment.

Arguments

• handle: EK file handle
• segno: Number of segment to add column to
• column: Column name
• ivals: Integer values to add to column
• nlflgs: Array of null flags for column entries
• rcptrs: Record pointers for segment

References

• NAIF Documentation

ekappr(handle, segno)

Append a new, empty record at the end of a specified E-kernel segment.

Arguments

• handle: File handle
• segno: Segment number

Output

Returns the number of appended record.

References

• NAIF Documentation

ekbseg(handle, tabnam, cnames, decls)

Start a new segment in an E-kernel.

Arguments

• handle: File handle
• tabnam: Table name
• cnames: Names of columns
• decls: Declarations of columns

Output

Returns the segment number.

References

• NAIF Documentation

ekccnt(table)

Return the number of distinct columns in a specified, currently loaded table

Arguments

• table: Name of table

Output

Returns the count of distinct, currently loaded columns.

References

• NAIF Documentation

ekcii(table, cindex, lenout=256)

Return attribute information about a column belonging to a loaded EK table, specifying the column by table and index.

Arguments

• table: Name of table containing column
• cindex: Index of column whose attributes are to be found
• lenout: Maximum allowed length of column name (default: 256)

Output

• column: Name of column
• attdsc: Column attribute descriptor

References

• NAIF Documentation

ekcls(handle)

Close an E-kernel.

Arguments

• handle: EK file handle

References

• NAIF Documentation

ekdelr(handle, segno, recno)

Delete a specified record from a specified E-kernel segment.

Arguments

• handle: File handle
• segno: Segment number
• recno: Record number

References

• NAIF Documentation

ekffld(handle, segno, rcptrs)

Complete a fast write operation on a new E-kernel segment.

Arguments

• handle: File handle
• segno: Segment number
• rcptrs: Record pointers

References

• NAIF Documentation

ekfind(query, lenout=256)

Find E-kernel data that satisfy a set of constraints.

Arguments

• query: Query specifying data to be found.
• lenout: Declared length of output error message string (default: 256)

Output

Returns the number of matching rows.

References

• NAIF Documentation

ekgc(selidx, row, elment, lenout=256)

Return an element of an entry in a column of character type in a specified row.

Arguments

• selidx: Index of parent column in SELECT clause
• row: Row to fetch from
• elment: Index of element, within column entry, to fetch
• lenout: Maximum length of column element (default: 256)

Output

Returns the character string element of column entry or missing if it was null or nothing if the column was not found.

References

• NAIF Documentation

ekgd(selidx, row, element)

Return an element of an entry in a column of double precision type in a specified row.

Arguments

• selidx: Index of parent column in SELECT clause
• row: Row to fetch from
• elment: Index of element, within column entry, to fetch

Output

Returns the double precision element of column entry or missing if it was null or nothing if the column was not found.

References

• NAIF Documentation

ekgi(selidx, row, element)

Return an element of an entry in a column of integer type in a specified row.

Arguments

• selidx: Index of parent column in SELECT clause
• row: Row to fetch from
• elment: Index of element, within column entry, to fetch

Output

Returns the integer element of column entry or missing if it was null or nothing if the column was not found.

References

• NAIF Documentation

ekifld(handle, tabnam, nrows, cnames, decls)

Initialize a new E-kernel segment to allow fast writing.

Arguments

• handle: File handle
• tabnam: Table name
• nrows: Number of rows in the segment
• cnames: Names of columns
• decls: Declarations of columns

Output

• segno: Segment number
• rcptrs: Array of record pointers

References

• NAIF Documentation

ekinsr(handle, segno, recno)

Add a new, empty record to a specified E-kernel segment at a specified index.

Arguments

• handle: File handle
• segno: Segment number
• recno: Record number

References

• NAIF Documentation

eklef(fname)

Load an EK file, making it accessible to the EK readers.

Arguments

• fname: Name of EK file to load

Output

Returns the file handle of loaded EK file.

References

• NAIF Documentation

eknelt(selidx, row)

Return the number of elements in a specified column entry in the current row.

Arguments

• selidx: Index of parent column in SELECT clause
• row: Row containing element

Output

Returns the number of elements in entry in current row.

References

• NAIF Documentation

eknseg(handle)

Return the number of segments in a specified EK.

Arguments

• handle: EK file handle

Output

Returns the number of segments in the specified E-kernel.

References

• NAIF Documentation

ekntab()

Return the number of loaded EK tables.

References

• NAIF Documentation

ekopn(fname, ifname, ncomch)

Open a new E-kernel file and prepare the file for writing.

Arguments

• fname: Name of EK file
• ifname: Internal file name
• ncomch: The number of characters to reserve for comments

Output

Return the handle attached to the new EK file.

References

• NAIF Documentation

ekopr(fname)

Open an existing E-kernel file for reading.

Arguments

• fname: Name of EK file

Output

Returns the handle attached to the EK file.

References

• NAIF Documentation

ekops()

Open a scratch (temporary) E-kernel file and prepare the file for writing.

Output

Returns the handle attached to the EK file.

References

• NAIF Documentation

ekopw(fname)

Open an existing E-kernel file for writing.

Arguments

• fname: Name of EK file

Output

Returns the handle attached to the EK file.

References

• NAIF Documentation

ekpsel(query, msglen=256, tablen=256, collen=256)

Parse the SELECT clause of an EK query, returning full particulars concerning each selected item.

Arguments

• query: EK query
• msglen: Available space in the output error message string (default: 256)
• tablen: Length of strings in `tabs' output array (default: 256)
• collen: Length of strings in `cols' output array (default: 256)

Output

• xbegs: Begin positions of expressions in SELECT clause
• xends: End positions of expressions in SELECT clause
• xtypes: Data types of expressions
• xclass: Classes of expressions
• tabs: Names of tables qualifying SELECT columns
• cols: Names of columns in SELECT clause of query

References

• NAIF Documentation

ekrcec(handle, segno, recno, column, lenout=256, nelts=100)

Read data from a character column in a specified EK record.

Arguments

• handle: Handle attached to EK file
• segno: Index of segment containing record
• recno: Record from which data is to be read
• column: Column name
• lenout: Maximum length of output strings
• nelts: Maximum number of elements to return (default: 100)

Output

Returns the character values in column entry or missing if they are null.

References

• NAIF Documentation

ekrced(handle, segno, recno, column, nelts=100)

Read data from a double precision column in a specified EK record.

Arguments

• handle: Handle attached to EK file
• segno: Index of segment containing record
• recno: Record from which data is to be read
• column: Column name
• nelts: Maximum number of elements to return (default: 100)

Output

Returns the values in column entry.

References

• NAIF Documentation

ekrcei(handle, segno, recno, column, nelts=100)

Read data from an integer column in a specified EK record.

Arguments

• handle: Handle attached to EK file
• segno: Index of segment containing record
• recno: Record from which data is to be read
• column: Column name
• nelts: Maximum number of elements to return (default: 100)

Output

Returns the values in column entry.

References

• NAIF Documentation

ekssum(handle, segno)

Return summary information for a specified segment in a specified EK.

Arguments

• handle: Handle of EK
• segno: Number of segment to be summarized

Output

Returns the EK segment summary.

References

• NAIF Documentation

ektnam(n, lenout=256)

Return the name of a specified, loaded table.

Arguments

• n: Index of table
• lenout: Maximum table name length (default: 256)

Output

Returns the name of table.

References

• NAIF Documentation

ekucec(handle, segno, recno, column, cvals, isnull)

Update a character column entry in a specified EK record.

Arguments

• handle: EK file handle
• segno: Index of segment containing record
• recno: Record to which data is to be updated
• column: Column name
• cvals: Character values comprising new column entry
• isnull: Flag indicating whether column entry is null

References

• NAIF Documentation

ekuced(handle, segno, recno, column, dvals, isnull)

Update a double precision column entry in a specified EK record.

Arguments

• handle: Handle attached to EK file
• segno: Index of segment containing record
• recno: Record in which entry is to be updated
• column: Column name
• dvals: Double precision values comprising new column entry
• isnull: Flag indicating whether column entry is null

References

• NAIF Documentation

ekucei(handle, segno, recno, column, dvals, isnull)

Update an integer column entry in a specified EK record.

Arguments

• handle: Handle attached to EK file
• segno: Index of segment containing record
• recno: Record in which entry is to be updated
• column: Column name
• ivals: Integer values comprising new column entry
• isnull: Flag indicating whether column entry is null

References

• NAIF Documentation

ekuef(handle)

Unload an EK file, making its contents inaccessible to the EK reader routines, and clearing space in order to allow other EK files to be loaded.

Arguments

• handle: Handle of EK file

References

• NAIF Documentation

Convert an ellipse to a center vector and two generating vectors. The selected generating vectors are semi-axes of the ellipse.

Arguments

• ellipse: An ellipse

Output

Returns the center and semi-axes of ellipse.

References

• NAIF Documentation

elem[c/d/i](item, cell)

eqncpv(et, epoch, eqel, rapol, decpol)

Compute the state (position and velocity of an object whose trajectory is described via equinoctial elements relative to some fixed plane (usually the equatorial plane of some planet).

Arguments

• et: Epoch in seconds past J2000 to find state
• epoch: Epoch of elements in seconds past J2000
• eqel: Array of equinoctial elements
• rapol: Right Ascension of the pole of the reference plane
• decpol: Declination of the pole of the reference plane

Output

Returns the state of the object described by eqel.

References

• NAIF Documentation

eqstr(a, b)

Determine whether two strings are equivalent.

Arguments

• a, b: Arbitrary character strings

Output

Returns true if a and b are equivalent.

References

• NAIF Documentation

esrchc(value, array)

Search for a given value within a character string array.

Arguments

• value: Key value to be found in array
• array: Character string array to search

Output

Returns the index of the first equivalent array entry, or -1 if no equivalent element is found.

References

• NAIF Documentation

et2lst(et, body, lon, typ, timlen=128, ampmlen=128)

Given an ephemeris epoch, compute the local solar time for an object on the surface of a body at a specified longitude.

Arguments

• et: Epoch in seconds past J2000 epoch
• body: ID-code of the body of interest
• lon: Longitude of surface point (radians)
• typ: Type of longitude "PLANETOCENTRIC", etc
• timlen: Available room in output time string (default: 128)
• ampmlen: Available room in output `ampm' string (default: 128)

Output

• hr: Local hour on a "24 hour" clock
• mn: Minutes past the hour
• sc: Seconds past the minute
• time: String giving local time on 24 hour clock
• ampm: String giving time on A.M./ P.M. scale

References

• NAIF Documentation

et2utc(et, format, prec)

Convert an input time from ephemeris seconds past J2000 to Calendar, Day-of-Year, or Julian Date format, UTC.

Arguments

• et: Input epoch, given in ephemeris seconds past J2000
• format: Format of output epoch. It may be any of the following:
  • :C: Calendar format, UTC
  • :D: Day-of-Year format, UTC
  • :J: Julian Date format, UTC
  • :ISOC: ISO Calendar format, UTC
  • :ISOD: ISO Day-of-Year format, UTC
• prec: Digits of precision in fractional seconds or days

Output

Returns an output time string equivalent to the input epoch, in the specified format.

References

• NAIF Documentation

etcal(et, lenout=128)

Convert from an ephemeris epoch measured in seconds past the epoch of J2000 to a calendar string format using a formal calendar free of leapseconds.

Arguments

• et: Ephemeris time measured in seconds past J2000
• lenout: Length of output string (default: 128)

Output

Returns a standard calendar representation of et.

References

• NAIF Documentation

eul2m(angle3, angle2, angle1, axis3, axis2, axis1)

Construct a rotation matrix from a set of Euler angles.

Arguments

• angle3, angle2, angle1: Rotation angles about third, second, and first rotation axes (radians)
• axis3, axis2, axis1: Axis numbers of third, second, and first rotation axes

Output

A rotation matrix corresponding to the product of the 3 rotations.

References

• NAIF Documentation

eul2xf(eulang, axisa, axisb, axisc)

Compute a state transformation from an Euler angle factorization of a rotation and the derivatives of those Euler angles.

Arguments

• eulang: An array of Euler angles and their derivatives
• axisa: Axis A of the Euler angle factorization
• axisb: Axis B of the Euler angle factorization
• axisc: Axis C of the Euler angle factorization

Output

Returns a state transformation matrix.

References

• NAIF Documentation

expool(name)

Confirm the existence of a kernel variable in the kernel pool.

Arguments

• name: Name of the variable whose value is to be returned

Output

Returns true when the variable is in the pool.

References

• NAIF Documentation

fovray(inst, raydir, rframe, abcorr, observer, et)

Determine if a specified ray is within the field-of-view (FOV) of a specified instrument at a given time.

Arguments

• inst: Name or ID code string of the instrument
• raydir: Ray's direction vector
• rframe: Body-fixed, body-centered frame for target body
• abcorr: Aberration correction flag
• observer: Name or ID code string of the observer
• et: Time of the observation (seconds past J2000)

Output

Returns true if the ray is visible.

References

• NAIF Documentation

fovtrg(inst, target, tshape, tframe, abcorr, obsrvr, et)

Determine if a specified ephemeris object is within the field-of-view (FOV) of a specified instrument at a given time.

Arguments

• inst: Name or ID code string of the instrument.
• target: Name or ID code string of the target.
• tshape: Type of shape model used for the target.
• tframe: Body-fixed, body-centered frame for target body.
• abcorr: Aberration correction flag.
• obsrvr: Name or ID code string of the observer.
• et: Time of the observation (seconds past J2000).

Output

Returns true if the object is visible.

References

• NAIF Documentation

frame(x)

Given a vector x, this routine builds a right handed orthonormal frame x, y, z where the output x is parallel to the input x.

Arguments

• x: Input vector

Output

• x: Unit vector parallel to x on output
• y: Unit vector in the plane orthogonal to x
• z: Unit vector given by x × y

References

• NAIF Documentation

frinfo(frcode)

Retrieve the minimal attributes associated with a frame needed for converting transformations to and from it.

Arguments

• frcode: The id code for a reference frame

Output

• cent: The center of the frame
• frclss: The class (type) of the frame
• clssid: The idcode for the frame within its class

Returns nothing if no frame with id frcode could be found.

References

• NAIF Documentation

frmnam(frcode)

Retrieve the name of a reference frame associated with an id code.

Arguments

• frcode: The id code for a reference frame

Output

Returns the name associated with the reference frame.

References

• NAIF Documentation

furnsh(kernels...)

Load one or more SPICE kernels into a program.

Arguments

• kernels: Path(s) of SPICE kernels to load

References

• NAIF Documentation

gcpool(name; start=1, room=100, lenout=128)

Return the value of a kernel variable from the kernel pool.

Arguments

• name: Name of the variable whose value is to be returned
• start: Which component to start retrieving for name (default: 1)
• room: The largest number of values to return (default: 100)
• lenout: The length of the longest string to return (default: 128)

Output

Returns an array of values if the variable exists or nothing if not.

References

• NAIF Documentation

gdpool(name; start=1, room=100)

Return the value of a kernel variable from the kernel pool.

Arguments

• name: Name of the variable whose value is to be returned
• start: Which component to start retrieving for name (default: 1)
• room: The largest number of values to return (default: 100)

Output

Returns an array of values if the variable exists or nothing if not.

References

• NAIF Documentation

georec(lon, lat, alt, re, f)

Convert geodetic coordinates to rectangular coordinates.

Arguments

• lon: Geodetic longitude of point (radians)
• lat: Geodetic latitude of point (radians)
• alt: Altitude of point above the reference spheroid
• re: Equatorial radius of the reference spheroid
• f: Flattening coefficient

Output

Returns the rectangular coordinates of point.

References

• NAIF Documentation

getelm(frstyr, lines)

Given the "lines" of a two-line element set, parse the lines and return the elements in units suitable for use in SPICE software.

Arguments

• frstyr: Year of earliest representable two-line elements
• lines: A pair of "lines" containing two-line elements

Output

• epoch: The epoch of the elements in seconds past J2000
• elems: The elements converted to SPICE units

References

• NAIF Documentation

getfat(file, arclen=10, typlen=10)

Determine the file architecture and file type of most SPICE kernel files.

Arguments

• file: The name of a file to be examined
• arclen: Maximum length of output architecture string (default: 10)
• typlen: Maximum length of output type string (default: 10)

Output

• arch: The architecture of the kernel file
• typ: The type of the kernel file

References

• NAIF Documentation

getfov(instid, room=10, shapelen=128, framelen=128)

Return the field-of-view (FOV) parameters for a specified instrument. The instrument is specified by its NAIF ID code.

Arguments

• instid: NAIF ID of an instrument
• room: Maximum number of vectors that can be returned (default: 10)
• shapelen: Space available in the string shape (default: 128)
• framelen: Space available in the string frame (default: 128)

Output

Returns a tuple consisting of

• shape: Instrument FOV shape
• frame: Name of the frame in which FOV vectors are defined
• bsight: Boresight vector
• bounds: FOV boundary vectors

References

• NAIF Documentation

gfdist(target, abcorr, obsrvr, relate, refval, adjust, step, nintvls, cnfine)

Return the time window over which a specified constraint on observer-target distance is met.

Arguments

• target: Name of the target body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• relate: Relational operator
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is confined

Output

Returns a window containing the results.

References

• NAIF Documentation

gfevnt(udstep, udrefn, gquant, qnpars, lenvals, qpnams, qcpars, qdpars, qipars, qlpars,
       op, refval, tol, adjust, rpt, udrepi, udrepu, udrepf, nintvls, bail, udbail, cnfine)

Determine time intervals when a specified geometric quantity satisfies a specified mathematical condition.

Arguments

• udstep: Name of the routine that computes and returns a time step
• udrefn: Name of the routine that computes a refined time
• gquant: Type of geometric quantity
• qpnams: Names of quantity definition parameters
• qcpars: Array of character quantity definition parameters
• qdpars: Array of double precision quantity definition parameters
• qipars: Array of integer quantity definition parameters
• qlpars: Array of logical quantity definition parameters
• op: Operator that either looks for an extreme value (max, min, local, absolute) or compares the geometric quantity value and a number
• refval: Reference value
• tol: Convergence tolerance in second
• adjust: Absolute extremum adjustment value
• rpt: Progress reporter on (true) or off (false)
• udrepi: Function that initializes progress reporting
• udrepu: Function that updates the progress report
• udrepf: Function that finalizes progress reporting
• nintvls: Workspace window interval coun
• cnfine: SPICE window to which the search is restricted

Output

Returns a window containing the results.

References

• NAIF Documentation

gffove!(inst, tshape, raydir, target, tframe, abcorr, obsrvr, tol, udstep, udrefn,
            rpt, udrepi, udrepu, udrepf, cnfine, result)

Determine time intervals when a specified target body or ray intersects the space bounded by the field-of-view (FOV) of a specified instrument.

Arguments

• inst: Name of the instrument
• tshape: Type of shape model used for target body
• raydir: Ray's direction vector
• target: Name of the target body
• tframe: Body-fixed, body-centered frame for target body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• tol: Convergence tolerance in seconds
• udstep: Name of the routine returns a time step
• udrefn: Name of the routine that computes a refined time
• rpt: Progress report flag
• udrepi: Function that initializes progress reporting
• udrepu: Function that updates the progress report
• udrepf: Function that finalizes progress reporting
• cnfine: SPICE window to which the search is restricted
• result: Window containing the results

Output

Returns result.

References

• NAIF Documentation

gfilum(method, angtyp, target, illmn, fixref, abcorr, obsrvr, spoint, relate, refval,
       adjust, step, nintvls, cnfine)

Return the time window over which a specified constraint on the observed phase, solar incidence, or emission angle at a specifed target body surface point is met.

Arguments

• method: Computation method
• angtyp: Type of illumination angle
• target: Name of the target body
• illmn: Name of the illumination source
• fixref: Body-fixed, body-centered target body frame
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• spoint: Body-fixed coordinates of a target surface point
• relate: Relational operator
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is confined

Output

Returns a window containing the results.

References

• NAIF Documentation

function gfocce!(occtyp, front, fshape, fframe, back, bshape, bframe, abcorr, obsrvr, tol,
    udstep, udrefn, rpt, udrepi, udrepu, udrepf, cnfine, result)

Determine time intervals when an observer sees one target occulted by another.

Arguments

• occtyp: Type of occultation
• front: Name of body occulting the other
• fshape: Type of shape model used for front body
• fframe: Body-fixed, body-centered frame for front body
• back: Name of body occulted by the other
• bshape: Type of shape model used for back body
• bframe: Body-fixed, body-centered frame for back body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• tol: Convergence tolerance in seconds
• udstep: Name of the routine that returns a time step
• udrefn: Name of the routine that computes a refined time
• rpt: Progress report flag
• udrepi: Function that initializes progress reporting
• udrepu: Function that updates the progress report
• udrepf: Function that finalizes progress reporting
• cnfine: SPICE window to which the search is restricted
• result: SPICE window containing results

Output

Returns result.

References

• NAIF Documentation

gfoclt(occtyp, front, fshape, fframe, back, bshape, bframe, abcorr, obsrvr, step, cnfine,
       maxwin=100)

Determine time intervals when an observer sees one target occulted by, or in transit across, another.

The surfaces of the target bodies may be represented by triaxial ellipsoids or by topographic data provided by DSK files.

Arguments

• occtyp: Type of occultation
• front: Name of body occulting the other
• fshape: Type of shape model used for front body
• fframe: Body-fixed, body-centered frame for front body
• back: Name of body occulted by the other
• bshape: Type of shape model used for back body
• bframe: Body-fixed, body-centered frame for back body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• step: Step size in seconds for finding occultation events
• cnfine: Window to which the search is restricted
• maxwin: Maximum size of the output window (default: 100)

Output

Returns a window containing the results.

References

• NAIF Documentation

gfpa(result, target, illmn, abcorr, obsrvr, relate, refval, adjust, step, nintvls, cnfine)

Determine time intervals for which a specified constraint on the phase angle between an illumination source, a target, and observer body centers is met.

Arguments

• target: Name of the target body
• illmn: Name of the illuminating body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• relate: Relational operator
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is confined

Output

Returns a window containing the results.

References

• NAIF Documentation

gfposc(target, frame, abcorr, obsrvr, crdsys, coord, relate, refval, adjust, step,
       nintvls, cnfine)

Determine time intervals for which a coordinate of an observer-target position vector satisfies a numerical constraint.

Arguments

• target: Name of the target body
• frame: Name of the reference frame for coordinate calculations
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• crdsys: Name of the coordinate system containing coord
• coord: Name of the coordinate of interest
• relate: Operator that either looks for an extreme value (max, min, local, absolute) or compares the coordinate value and refval
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is restricted

Output

Returns a window containing the results.

References

• NAIF Documentation

gfrefn(t1, t2, s1, s2)

For those times when we can't do better, we use a bisection method to find the next time at which to test for state change.

Arguments

• t1: One of two values bracketing a state change
• t2: The other value that brackets a state change
• s1: State at t1
• s2: State at t2

Output

Returns the new value at which to check for transition.

References

• NAIF Documentation

gfrepf()

Finish a GF progress report.

References

• NAIF Documentation

gfrepi(window, begmss, endmss)

Initialize a search progress report.

Arguments

• window: A window over which a job is to be performed
• begmss: Beginning of the text portion of the output message
• endmss: End of the text portion of the output message

References

• NAIF Documentation

gfrepu(ivbeg, ivend, time)

Tell the progress reporting system how far a search has progressed.

Arguments

• ivbeg: Start time of work interval
• ivend: End time of work interval
• time: Current time being examined in the search process

References

• NAIF Documentation

gfrfov(inst, raydir, rframe, abcorr, obsrvr, step, cnfine, maxwin=10000)

Determine time intervals when a specified ray intersects the space bounded by the field-of-view (FOV) of a specified instrument.

Arguments

• inst: Name of the instrument
• raydir: Ray's direction vector
• rframe: Reference frame of ray's direction vector
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• step: Step size in seconds for finding FOV events
• cnfine: SPICE window to which the search is restricted
• maxwin: Maximum length of the output window (default: 10000)

Output

Returns a window containing the results.

References

• NAIF Documentation

gfrr(target, abcorr, obsrvr, relate, refval, adjust, step, nintvls, cnfine)

Determine time intervals for which a specified constraint on the observer-target range rate is met.

Arguments

• target: Name of the target body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• relate: Relational operator
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is confined

Output

Returns a window containing the results.

References

• NAIF Documentation

Determine time intervals when the angular separation between the position vectors of two target bodies relative to an observer satisfies a numerical relationship.

Arguments

• targ1: Name of first body
• shape1: Name of shape model describing the first body
• frame1: The body-fixed reference frame of the first body
• targ2: Name of second body
• shape2: Name of the shape model describing the second body
• frame2: The body-fixed reference frame of the second body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• relate: Operator that either looks for an extreme value (max, min, local, absolute) or compares the angular separation value and refval
• refval: Reference value
• adjust: Absolute extremum adjustment value
• step: Step size in seconds for finding angular separation events
• nintvls: Workspace window interval count
• cnfine: Window to which the search is restricted

Output

Returns a window containing the results.

References

• NAIF Documentation

gfsntc(target, fixref, method, abcorr, obsrvr, dref, dvec, crdsys, coord, relate, refval,
       adjust, step, nintvls, cnfine)

Determine time intervals for which a coordinate of an surface intercept position vector satisfies a numerical constraint.

Arguments

• target: Name of the target body
• fixref: Body fixed frame associated with target
• method: Name of method type for surface intercept calculation
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• dref: Reference frame of direction vector dvec
• dvec: Pointing direction vector from obsrvr
• crdsys: Name of the coordinate system containing COORD
• coord: Name of the coordinate of interest
• relate: Operator that either looks for an extreme value (max, min, local, absolute) or compares the coordinate value and refval
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is restricted

Output

Returns a window containing the results.

References

• NAIF Documentation

gfsstp(step)

Set the step size to be returned by gfstep.

Arguments

• step: Time step to take

References

• NAIF Documentation

gfstep()

Return the time step set by the most recent call to gfsstp.

Arguments

• step: Time step to take

References

• NAIF Documentation

gfstol(value)

Override the default GF convergence value used in the high level GF routines.

Arguments

• value: Double precision value returned or to store

References

• NAIF Documentation

gfsubc(target, fixref, method, abcorr, obsrvr, crdsys, coord, relate, refval, adjust, step,
       nintvls, cnfine)

Determine time intervals for which a coordinate of an subpoint position vector satisfies a numerical constraint.

Arguments

• target: Name of the target body
• fixref: Body fixed frame associated with target
• method: Name of method type for subpoint calculation
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• crdsys: Name of the coordinate system containing coord
• coord: Name of the coordinate of interest
• relate: Operator that either looks for an extreme value (max, min, local, absolute) or compares the coordinate value and refval
• refval: Reference value
• adjust: Adjustment value for absolute extrema searches
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: Window to which the search is restricted

Output

Returns a window containing the results.

References

• NAIF Documentation

gftfov(inst, target, tshape, tframe, abcorr, obsrvr, step, nintvls, cnfine)

Determine time intervals when a specified ephemeris object intersects the space bounded by the field-of-view (FOV) of a specified instrument.

Arguments

• inst: Name of the instrument
• target: Name of the target body
• tshape: Type of shape model used for target body
• tframe: Body-fixed, body-centered frame for target body
• abcorr: Aberration correction flag
• obsrvr: Name of the observing body
• step: Step size in seconds for finding FOV events
• nintvls: Workspace window interval count
• cnfine: Window to which the search is restricted

Output

Returns a window containing the results.

References

• NAIF Documentation

gfudb!(udfuns, udfunb, step, cnfine, result)

Perform a GF search on a user defined boolean quantity.

Arguments

• udfuns: Name of the routine that computes a scalar quantity of interest corresponding to an et, e.g. f(et) = ...
• udfunb: Name of the routine returning the boolean value corresponding to an et, e.g. g(f, et) = ...
• step: Step size used for locating extrema and roots
• cnfine: Window to which the search is restricted
• result: Window containing results

Output

Returns result.

References

• NAIF Documentation

gfuds!(udfuns, udqdec, relate, refval, adjust, step, nintvls, cnfine, result)

Perform a GF search on a user defined scalar quantity.

Arguments

• udfuns: Name of the routine that computes the scalar quantity of interest at some time, e.g. f(et) = ...
• udqdec: Name of the routine that computes whether the scalar quantity is decreasing, e.g. g(f, et) = ...
• relate: Operator that either looks for an extreme value (max, min, local, absolute) or compares the geometric quantity value and a number
• refval: Value used as reference for scalar quantity condition
• adjust: Allowed variation for absolute extremal geometric conditions
• step: Step size used for locating extrema and roots
• nintvls: Workspace window interval count
• cnfine: SPICE window to which the search is restricted
• result: SPICE window containing results

Output

Returns result.

References

• NAIF Documentation

gipool(name; start=1, room=100)

Return the value of a kernel variable from the kernel pool.

Arguments

• name: Name of the variable whose value is to be returned
• start: Which component to start retrieving for name (default: 1)
• room: The largest number of values to return (default: 100)

Output

Returns an array of values if the variable exists or nothing if not.

References

• NAIF Documentation

gnpool(name, start, room, lenout=128)

Return names of kernel variables matching a specified template.

Arguments

• name: Template that names should match
• start: Index of first matching name to retrieve
• room: The largest number of values to return
• lenout: Length of strings in output array kvars (default: 128)

Output

Returns lernel pool variables whose names match name.

References

• NAIF Documentation

halfpi()

hrmint(xvals, yvals, x)

Evaluate a Hermite interpolating polynomial at a specified abscissa value.

Arguments

• xvals: Abscissa values
• yvals: Ordinate and derivative values
• x: Point at which to interpolate the polynomial

Output

• f: Interpolated function value at x
• df: Interpolated function's derivative at x

References

• NAIF Documentation

hx2dp(str)

Convert a string representing a double precision number in a base 16 "scientific notation" into its equivalent double precision number.

Arguments

• str: Hex form string to convert to double precision

Output

• dp: Double precision value to be returned

References

• NAIF Documentation

illumf(method, target, ilusrc, et, fixref, abcorr, obsrvr, spoint)

Compute the illumination angles - phase, incidence, and emission - at a specified point on a target body. Return logical flags indicating whether the surface point is visible from the observer's position and whether the surface point is illuminated.

The target body's surface is represented using topographic data provided by DSK files, or by a reference ellipsoid.

The illumination source is a specified ephemeris object.

Arguments

• method: Computation method
• target: Name of target body
• ilusrc: Name of illumination source
• et: Epoch in TDB seconds past J2000 TDB
• fixref: Body-fixed, body-centered target body frame
• abcorr: Aberration correction flag
• obsrvr: Name of observing body
• spoint: Body-fixed coordinates of a target surface point

Output

• trgepc: Target surface point epoch
• srfvec: Vector from observer to target surface point
• phase: Phase angle at the surface point
• incdnc: Source incidence angle at the surface point
• emissn: Emission angle at the surface point
• visibl: Visibility flag (true if visible)
• lit: Illumination flag (true if illuminated)

References

• NAIF Documentation

illumg(method, target, ilusrc, et, fixref, obsrvr, spoint, abcorr)

Find the illumination angles (phase, incidence, and emission) at a specified surface point of a target body.

The surface of the target body may be represented by a triaxial ellipsoid or by topographic data provided by DSK files.

The illumination source is a specified ephemeris object.

Arguments

• method: Computation method.
• target: Name of target body.
• ilusrc: Name of illumination source.
• et: Epoch in ephemeris seconds past J2000 TDB.
• fixref: Body-fixed, body-centered target body frame.
• obsrvr: Name of observing body.
• spoint: Body-fixed coordinates of a target surface point.
• abcorr: Aberration correction.

Output

• trgepc: Sub-solar point epoch.
• srfvec: Vector from observer to sub-solar point.
• phase: Phase angle at the surface point.
• incdnc: Solar incidence angle at the surface point.
• emissn: Emission angle at the surface point.

References

• NAIF Documentation

ilumin(method, target, et, fixref, obsrvr, spoint, abcorr)

Find the illumination angles (phase, solar incidence, and emission) at a specified surface point of a target body.

Arguments

• method: Computation method
• target: Name of target body
• et: Epoch in ephemeris seconds past J2000 TDB
• fixref: Body-fixed, body-centered target body frame
• obsrvr: Name of observing body
• spoint: Body-fixed coordinates of a target surface point
• abcorr: Aberration correction

Output

• trgepc: Sub-solar point epoch
• srfvec: Vector from observer to sub-solar point
• phase: Phase angle at the surface point
• incdnc: Solar incidence angle at the surface point
• emissn: Emission angle at the surface point

References

• NAIF Documentation

inedpl(a, b, c, plane)

Find the intersection of a triaxial ellipsoid and a plane.

Arguments

• a: Length of ellipsoid semi-axis lying on the x-axis
• b: Length of ellipsoid semi-axis lying on the y-axis
• c: Length of ellipsoid semi-axis lying on the z-axis
• plane: Plane that intersects ellipsoid

Output

• ellipse: Intersection ellipse

Returns nothing if no ellipse could be found.

References

• NAIF Documentation

inelpl(ellips, plane)

Find the intersection of an ellipse and a plane.

Arguments

• ellips: An ellipse
• plane: A plane

Output

• nxpts: Number of intersection points of ellipse and plane
• xpt1, xpt2: Intersection points

References

• NAIF Documentation

inrypl(vertex, dir, plane)

Find the intersection of a ray and a plane.

Arguments

• vertex, dir: Vertex and direction vector of ray
• plane: A plane

Output

• nxpts: Number of intersection points of ray and plane
• xpt1, xpt2: Intersection points

References

• NAIF Documentation

insrtc!(set, item)

Insert an item into a character set.

Arguments

• set: Insertion set
• item: Item to be inserted

Output

Returns the updated set.

References

• NAIF Documentation

insrtd!(set, item)

Insert an item into a double set.

Arguments

• set: Insertion set
• item: Item to be inserted

Output

Returns the updated set.

References

• NAIF Documentation

insrti!(set, item)

Insert an item into an integer set.

Arguments

• set: Insertion set
• item: Item to be inserted

Output

Returns the updated set.

References

• NAIF Documentation

inter(a, b)

Intersect two sets of any data type to form a third set.

Arguments

• a: First input set
• b: Second input set

Output

Returns intersection of a and b.

References

• NAIF Documentation

intmax()

intmin()

invert(matrix)

invort(matrix)

isordv(vec)

isrchc(value, array)

isrchd(value, array)

isrchi(value, array)

isrot(m, ntol, dtol)

Indicate whether a 3x3 matrix is a rotation matrix.

Arguments

• m: A matrix to be tested
• ntol: Tolerance for the norms of the columns of m
• dtol: Tolerance for the determinant of a matrix whose columns are the unitized columns of m

Output

Returns true if m is a rotation matrix.

References

• NAIF Documentation

iswhsp(str)

j1900()

Returns the Julian Date of 1899 DEC 31 12:00:00 (1900 JAN 0.5).

https://naif.jpl.nasa.gov/pub/naif/toolkitdocs/C/cspice/j1900c.html

j1950()

Returns the Julian Date of 1950 JAN 01 00:00:00 (1950 JAN 1.0).

https://naif.jpl.nasa.gov/pub/naif/toolkitdocs/C/cspice/j1950c.html

j2000()

Returns the Julian Date of 2000 JAN 01 12:00:00 (2000 JAN 1.5).

https://naif.jpl.nasa.gov/pub/naif/toolkitdocs/C/cspice/j2000c.html

j2100()

Returns the Julian Date of 2100 JAN 01 12:00:00 (2100 JAN 1.5).

https://naif.jpl.nasa.gov/pub/naif/toolkitdocs/C/cspice/j2100c.html

jyear()

Returns the number of seconds per Julian year.

https://naif.jpl.nasa.gov/pub/naif/toolkitdocs/C/cspice/jyearc.html

kclear()

Clear the KEEPER subsystem: unload all kernels, clear the kernel pool, and re-initialize the subsystem. Existing watches on kernel variables are retained.

References

• NAIF Documentation

kdata(which, kind, fillen=1024, srclen=256)

Return data for the n-th kernel that is among a list of specified kernel types.

Arguments

• which: Index of kernel to fetch from the list of kernels
• kind: The kind of kernel to which fetches are limited
• fillen: Available space in output file string
• srclen: Available space in output source string

Output

Returns nothing if no kernel was found or a tuple consisting of

• file: The name of the kernel file
• filtyp: The type of the kernel
• source: Name of the source file used to load file
• handle: The handle attached to file

References

• NAIF Documentation

kinfo(file, srclen=256)

Arguments

• file: Name of a kernel to fetch information for
• srclen: Available space in output source string

Output

Returns nothing if no kernel was found or a tuple consisting of

• filtyp: The type of the kernel
• source: Name of the source file used to load file
• handle: The handle attached to file

References

• NAIF Documentation

kplfrm(frmcls)

Return a SPICE set containing the frame IDs of all reference frames of a given class having specifications in the kernel pool.

Arguments

• frmcls: Frame class
• size: Size of the output set

Output

Returns the set of ID codes of frames of the specified class.

References

• NAIF Documentation

ktotal(kind)

Return the current number of kernels that have been loaded via the KEEPER interface that are of a specified type.

References

• NAIF Documentation

kxtrct(keywd, terms, string)

Locate a keyword in a string and extract the substring from the beginning of the first word following the keyword to the beginning of the first subsequent recognized terminator of a list.

Arguments

• keywd: Word that marks the beginning of text of interest
• terms: Set of words, any of which marks the end of text
• string: String containing a sequence of words

Output

Returns nothing if keywd was found or a tuple consisting of

• string: The input string with the text of interest removed
• substr: String from end of keywd to beginning of first terms item found

References

• NAIF Documentation

lastnb(str)

latcyl(radius, lon, lat)

Convert from latitudinal coordinates to cylindrical coordinates.

Arguments

• radius: Distance of a point from the origin
• lon: Angle of the point from the XZ plane in radians
• lat: Angle of the point from the XY plane in radians

Output

Return the tuple (r, lonc, z).

• r: Distance of the point from the z axis
• lonc: Angle of the point from the XZ plane in radians. 'lonc' is set equal to 'lon'
• z: Height of the point above the XY plane

References

• NAIF Documentation

latrec(radius, lon, lat)

Convert from latitudinal coordinates to rectangular coordinates.

Arguments

• radius: Distance of a point from the origin
• lon: Angle of the point from the XZ plane in radians
• lat: Angle of the point from the XY plane in radians

Output

Return the rectangular coordinates vector of the point.

References

• NAIF Documentation

latsph(radius, lon, lat)

Convert from latitudinal coordinates to spherical coordinates.

Arguments

• radius: Distance of a point from the origin
• lon: Angle of the point from the XZ plane in radians
• lat: Angle of the point from the XY plane in radians

Output

Return the tuple (rho, colat, lons).

• rho: Distance of the point from the origin
• colat: Angle of the point from positive z axis (radians)
• lons: Angle of the point from the XZ plane (radians)

References

• NAIF Documentation

latsrf(method, target, et, fixref, npts, lonlat)

Map array of planetocentric longitude/latitude coordinate pairs to surface points on a specified target body.

The surface of the target body may be represented by a triaxial ellipsoid or by topographic data provided by DSK files.

Arguments

• method: Computation method
• target: Name of target body
• et: Epoch in TDB seconds past J2000 TDB
• fixref: Body-fixed, body-centered target body frame
• lonlat: Array of longitude/latitude coordinate pairs

Output

Returns an array of surface points.

References

• NAIF Documentation

lcase(in)

ldpool(kernel)

Load the variables contained in a NAIF ASCII kernel file into the kernel pool.

Arguments

• kernel: Name of the kernel file

Output

None

References

• NAIF Documentation

lgrind(xvals, yvals, x)

Evaluate a Lagrange interpolating polynomial for a specified set of coordinate pairs, at a specified abscissa value. Return the value of both polynomial and derivative.

Arguments

• xvals: Abscissa values of coordinate pairs
• yvals: Ordinate values of coordinate pairs
• x: Point at which to interpolate the polynomial

Output

• p: The value at x of the unique polynomial of degree n-1 that fits the points in the plane defined by xvals and yvals
• dp: The derivative at x of the interpolating polynomial described above

References

• NAIF Documentation

limbpt(method, target, et, fixref, abcorr, corloc, obsrvr, refvec, rolstp, ncuts, schstp,
       soltol, maxn)

Find limb points on a target body. The limb is the set of points of tangency on the target of rays emanating from the observer. The caller specifies half-planes bounded by the observer-target center vector in which to search for limb points.

The surface of the target body may be represented either by a triaxial ellipsoid or by topographic data.

Arguments

• method: Computation method
• target: Name of target body
• et: Epoch in ephemeris seconds past J2000 TDB
• fixref: Body-fixed, body-centered target body frame
• abcorr: Aberration correction
• corloc: Aberration correction locus
• obsrvr: Name of observing body
• refvec: Reference vector for cutting half-planes
• rolstp: Roll angular step for cutting half-planes
• ncuts: Number of cutting half-planes
• schstp: Angular step size for searching
• soltol: Solution convergence tolerance
• maxn: Maximum number of entries in output arrays

Output

Returns the tuple (npts, points, epochs, tangts).

• npts: Counts of limb points corresponding to cuts
• points: Limb points
• epochs: Times associated with limb points
• tangts: Tangent vectors emanating from the observer

References

• NAIF Documentation

lmpool(cvals)

Load the variables contained in an internal buffer into the kernel pool.

Arguments

• cvals: An array that contains a SPICE text kernel

References

• NAIF Documentation

lparse(list, delim, nmax)

lparsm(list, delims, nmax)

lparss(list, delims)

lspcn(body, et, abcorr)

Compute L_s, the planetocentric longitude of the sun, as seen from a specified body.

Arguments

• body: Name of the central body
• et: Epoch in seconds past J2000 TDB
• abcorr: Aberration correction

Output

Returns the planetocentric longitude of the sun for the specified body at the specified time in radians.

References

• NAIF Documentation

lstlecd(x, array)

lstle[di](x, array)

lstltcd(x, array)

lstlt[di](x, array)

ltime(etobs, obs, dir, targ)

This routine computes the transmit (or receive) time of a signal at a specified target, given the receive (or transmit) time at a specified observer. The elapsed time between transmit and receive is also returned.

Arguments

• etobs: Epoch of a signal at some observer
• obs: NAIF ID of some observer
• dir: Direction the signal travels ( "->" or "<-" )
• targ: Time between transmit and receipt of the signal

Output

• ettarg: Epoch of the signal at the target
• obs: NAIF ID of some observer

References

• NAIF Documentation

lx4dec(string, first)

Scan a string from a specified starting position for the end of a decimal number.

Arguments

• string: Any character string
• first: First character to scan from in string

Output

• last: Last character that is part of a decimal number. If there is no such character, last will be returned with the value first-1.
• nchar: Number of characters in the decimal number

References

• NAIF Documentation

lx4num(string, first)

Scan a string from a specified starting position for the end of a number.

Arguments

• string: Any character string
• first: First character to scan from in string

Output

• last: Last character that is part of a number. If there is no such character, last will be returned with the value first-1.
• nchar: Number of characters in the number

References

• NAIF Documentation

lx4sgn(string, first)

Scan a string from a specified starting position for the end of a signed integer.

Arguments

• string: Any character string
• first: First character to scan from in string

Output

• last: Last character that is part of a signed integer. If there is no such character, last will be returned with the value first-1.
• nchar: Number of characters in the signed integer

References

• NAIF Documentation

lx4uns(string, first)

Scan a string from a specified starting position for the end of a unsigned integer.

Arguments

• string: Any character string
• first: First character to scan from in string

Output

• last: Last character that is part of an unsigned integer. If there is no such character, last will be returned with the value first-1.
• nchar: Number of characters in the unsigned integer

References

• NAIF Documentation

lxqstr(string, qchar, first)

Lex (scan) a quoted string.

Arguments

• string: String to be scanned
• qchar: Quote delimiter character
• first: Character position at which to start scanning

Output

• last: Character position of end of token
• nchar: Number of characters in token

References

• NAIF Documentation

m2eul(r, axis3, axis2, axis1)

Factor a rotation matrix as a product of three rotations about specified coordinate axes.

Arguments

• r: A rotation matrix to be factored
• axis3: Number of the third rotation axis
• axis2: Number of the second rotation axis
• axis1: Number of the first rotation axis

Output

A tuple consisting of the third, second, and first Euler angles in radians.

References

• NAIF Documentation

m2q(r)

Find a unit quaternion corresponding to a specified rotation matrix.

Arguments

• r: A rotation matrix

Output

A unit quaternion representing `r'

References

• NAIF Documentation

matchi(string, templ, wstr, wchar)

Determine whether a string is matched by a template containing wild cards. The pattern comparison is case-insensitive.

Arguments

• string: String to be tested
• templ: Template (with wild cards) to test against string
• wstr: Wild string token
• wchr: Wild character token