tipbod_c |

Table of contents## Proceduretipbod_c ( Transformation, inertial position to bodyfixed ) void tipbod_c ( ConstSpiceChar * ref, SpiceInt body, SpiceDouble et, SpiceDouble tipm[3][3] ) ## AbstractReturn a 3x3 matrix that transforms positions in inertial coordinates to positions in body-equator-and-prime-meridian coordinates. ## Required_ReadingFRAMES PCK NAIF_IDS ROTATION TIME ## KeywordsROTATION TRANSFORMATION ## Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- ref I ID of inertial reference frame to transform from. body I ID code of body. et I Epoch of transformation. tipm O Position transformation matrix, inertial to prime meridian. ## Detailed_Inputref is the NAIF name for an inertial reference frame. Acceptable names include: Name Description -------- -------------------------------- "J2000" Earth mean equator, dynamical equinox of J2000 "B1950" Earth mean equator, dynamical equinox of B1950 "FK4" Fundamental Catalog (4) "DE-118" JPL Developmental Ephemeris (118) "DE-96" JPL Developmental Ephemeris ( 96) "DE-102" JPL Developmental Ephemeris (102) "DE-108" JPL Developmental Ephemeris (108) "DE-111" JPL Developmental Ephemeris (111) "DE-114" JPL Developmental Ephemeris (114) "DE-122" JPL Developmental Ephemeris (122) "DE-125" JPL Developmental Ephemeris (125) "DE-130" JPL Developmental Ephemeris (130) "GALACTIC" Galactic System II "DE-200" JPL Developmental Ephemeris (200) "DE-202" JPL Developmental Ephemeris (202) See the Frames Required Reading frames.req for a full list of inertial reference frame names built into SPICE. The output `tipm' will give the transformation from this frame to the bodyfixed frame specified by `body' at the epoch specified by `et'. body is the integer ID code of the body for which the position transformation matrix is requested. Bodies are numbered according to the standard NAIF numbering scheme. The numbering scheme is explained in the NAIF IDs Required Reading naif_ids.req. et is the epoch at which the position transformation matrix is requested. (This is typically the epoch of observation minus the one-way light time from the observer to the body at the epoch of observation.) ## Detailed_Outputtipm is a 3x3 coordinate transformation matrix. It is used to transform positions from inertial coordinates to body fixed (also called equator and prime meridian --- PM) coordinates. Given a position P in the inertial reference frame specified by `ref', the corresponding bodyfixed position is given by the matrix vector product: tipm * s The X axis of the PM system is directed to the intersection of the equator and prime meridian. The Z axis points along the spin axis and points towards the same side of the invariable plane of the solar system as does earth's north pole. ## ParametersNone. ## Exceptions1) If the kernel pool does not contain all of the data required for computing the transformation matrix, `tipm', the error SPICE(INSUFFICIENTANGLES) is signaled by a routine in the call tree of this routine. 2) If the reference frame, `ref', is not recognized, an error is signaled by a routine in the call tree of this routine. 3) If the specified body code, `body', is not recognized, an error is signaled by a routine in the call tree of this routine. 4) If the `ref' input string pointer is null, the error SPICE(NULLPOINTER) is signaled. 5) If the `ref' input string has zero length, the error SPICE(EMPTYSTRING) is signaled. ## FilesNone. ## Particulars
## ExamplesThe numerical results shown for this example may differ across platforms. The results depend on the SPICE kernels used as input, the compiler and supporting libraries, and the machine specific arithmetic implementation. 1) Calculate the matrix to rotate a position vector from the J2000 frame to the Saturn fixed frame at a specified time, and use it to compute the position of Titan in Saturn's body-fixed frame. Use the meta-kernel shown below to load the required SPICE kernels. KPL/MK File name: tipbod_ex1.tm This meta-kernel is intended to support operation of SPICE example programs. The kernels shown here should not be assumed to contain adequate or correct versions of data required by SPICE-based user applications. In order for an application to use this meta-kernel, the kernels referenced here must be present in the user's current working directory. The names and contents of the kernels referenced by this meta-kernel are as follows: File name Contents --------- -------- sat375.bsp Saturn satellite ephemeris pck00010.tpc Planet orientation and radii naif0012.tls Leapseconds \begindata KERNELS_TO_LOAD = ( 'sat375.bsp', 'pck00010.tpc', 'naif0012.tls' ) \begintext End of meta-kernel Example code begins here. /. Program tipbod_ex1 ./ #include <stdio.h> #include "SpiceUsr.h" int main( ) { /. Local variables ./ SpiceDouble et; SpiceDouble lt; SpiceDouble pos [3]; SpiceDouble satvec [3]; SpiceDouble tipm [3][3]; SpiceInt satid; /. Load the kernels. ./ furnsh_c ( "tipbod_ex1.tm" ); /. The body ID for Saturn. ./ satid = 699; /. Retrieve the transformation matrix at some time. ./ str2et_c ( "Jan 1 2005", &et ); ## Restrictions1) The kernel pool must be loaded with the appropriate coefficients (from a text or binary PCK file) prior to calling this routine. ## Literature_ReferencesNone. ## Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) E.D. Wright (JPL) ## Version-CSPICE Version 1.0.3, 05-AUG-2021 (JDR) Edited the header to comply with NAIF standard. Added complete code example. Added frames.req to -Required_Reading. Updated -Exceptions section. -CSPICE Version 1.0.2, 14-AUG-2006 (EDW) Replace mention of ldpool_c with furnsh_c. -CSPICE Version 1.0.1, 13-APR-2000 (NJB) Made some minor updates and corrections in the code example. -CSPICE Version 1.0.0, 08-FEB-1998 (NJB) Based on SPICELIB Version 1.0.3, 10-MAR-1994 (KSZ). ## Index_Entriestransformation from inertial position to bodyfixed |

Fri Dec 31 18:41:14 2021