cspice_ckgpav |
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## AbstractCSPICE_CKGPAV returns pointing (attitude) and angular velocity for a specified spacecraft clock time. For important details concerning this module's function, please refer to the CSPICE routine ckgpav_c. ## I/OGiven: inst the scalar NAIF integer ID for the instrument, spacecraft, or other structure for which pointing is being requested sclkdp the double precision scalar encoded spacecraft clock time for which pointing is being requested tol the double precision scalar time tolerance in ticks (+/-), the units of encoded spacecraft clock time, about 'sclkdp' The C-matrix returned by ## ExamplesAny numerical results shown for this example may differ between platforms as the results depend on the SPICE kernels used as input and the machine specific arithmetic implementation. Retrieve pointing and angular velocity data from a Cassini CK kernel. ;; ;; Constants for this program: ;; ;; -- The code for the Cassini spacecraft is -82 ;; ;; -- The code for the Cassini spacecraft bus is -82000. ;; ;; -- The spacecraft clock ticks every 1/256 of a second. ;; ;; -- The reference frame we want is J2000. ;; ;; -- The bus boresight has direction ( 0, 0, 1 ) in the ;; bus (instrument) frame. ;; SC = -82 INST = -82000 REF = 'J2000' TICS = 256.d NPICS = 2 BORE = [ 0.d, 0.d, 1.d] CK = '/kernels/cassini/ck/030810_031019_c39_port1_pa.bc' SCLK = '/kernels/cassini/sclk/cas00082.tsc' SCLKCH = [ '1440000000.000' , '1445000000.000' ] ;; ;; Load the CK pointing file. ;; cspice_furnsh, CK ;; ;; Need to load a Cassini SCLK kernel to convert from ;; clock string to ticks and the leapseconds kernel. ;; cspice_furnsh, SCLK cspice_furnsh, 'standard.tm' ;; ;; ;; Calculate a tolerance for pointing data. Use 5 seconds, ;; convert to ticks by multiplying by the number of ticks ;; per second. ;; toltik = 5.d * TICS for i = 0, (NPICS-1) do begin ;; ;; cspice_ckgp requires encoded spacecraft clock time. ;; cspice_scencd, SC, SCLKCH[i], sclkdp ;; ;; Retrieve the 'REF' reference frame to 'INST' reference frame ;; transformation matrix at time sclkdp with a tolerance ;; 'toltik'. ;; ;; [INST] = [cmat][ref] ;; ## ParticularsNone. ## Required ReadingICY.REQ CK.REQ SCLK.REQ ## Version-Icy Version 1.0.2, 03-JUN-2010, BVS (JPL) Edits to header. Added warning regarding non-zero tolerance. -Icy Version 1.0.1, 09-JUN-2006, EDW (JPL) Edits to header. Improved argument descriptions. -Icy Version 1.0.0, 16-JUN-2003, EDW (JPL) ## Index_Entriesget ck pointing and angular velocity |

Wed Apr 5 17:57:59 2017