cspice_illum |
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## AbstractCSPICE_ILLUM calculates the illumination angles at a specified surface point of a target body. Deprecated: This routine has been superseded by the routine cspice_ilumin. This routine is supported for purposes of backward compatibility only. For important details concerning this module's function, please refer to the CSPICE routine illum_c. ## I/OGiven: target is the scalar string name of the target body. 'target' is case-insensitive, and leading and trailing blanks in 'target' are not significant. Optionally, you may supply a string containing the integer ID code for the object. For example both "MOON" and "301" are legitimate strings that indicate the moon is the target body. The target and observer define a state vector whose position component points from the observer to the target. et the scalar or N-vector of double precision epochs, specified in ephemeris seconds past J2000, at which the apparent illumination angles at the specified surface point on the target body, as seen from the observing body, are to be computed. abcorr the aberration correction to be used in computing the location and orientation of the target body and the location of the Sun. obsrvr the name of the observing body, typically a spacecraft, the earth, or a surface point on the earth. 'obsrvr' is case-insensitive, and leading and trailing blanks in 'obsrvr' are not significant. Optionally, you may supply a string containing the integer ID code for the object. For example both "EARTH" and "399" are legitimate strings that indicate the earth is the observer. spoint a double precision Cartesian 3-vector or 3xN array representing a surface point or points on the target body, expressed in rectangular body-fixed (body equator and prime meridian) coordinates. Each 'spoint' element (spoint[*,i]) corresponds to the same element index in 'et' (et[i]) and need not be visible from the observer's location at time 'et'. Note: The design of ## 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. ;; ;; Compute the time evolution of the phase, solar, and ;; emission angles for the intercept sub-point of the ;; MGS orbiter from Feb 1, 2003 to April 1, 2003. ;; TARGET = 'MARS' OBSERVER = 'MGS' CORRECT = 'LT+S' ;; ;; Assign the MGS kernel to a string variable. ;; Define the start and stop time for the computations. ;; MGS = '/kernels/MGS/spk/spk_m_030102-030403_021004.bsp' START_TIME = '1 Feb 2003' STOP_TIME = '1 APR 2003' ;; ;; Number of steps? ;; STEP = 75 ;; ;; Load the standard leapseconds, PCK kernels and the MGS ;; kernel. ;; cspice_furnsh, 'standard.tm' cspice_furnsh, MGS ;; ;; Convert the strings to ephemeris time J2000. ;; cspice_str2et, START_TIME, et_start cspice_str2et, STOP_TIME , et_stop ;; ;; Length of a step in seconds for STEP steps. ;; space = (et_stop - et_start)/double(STEP) ;; ;; Create a vector of ephemeris times. ;; et = et_start + dindgen(STEP)*space ;; ;; Start at 'et_start', take STEP steps ;; of space 'length'. At each time, calculate the ;; intercept sub-point of the observer, then calculate ;; the illumination angles at the sub-point. ;; cspice_subpt, 'Intercept', TARGET, et, CORRECT, $ OBSERVER, pos, alt ## ParticularsNone. ## Required ReadingICY.REQ KERNEL.REQ NAIF_IDS.REQ SPK.REQ TIME.REQ ## Version-Icy Version 1.1.2, 18-MAY-2010, BVS (JPL) Index lines now state that this routine is deprecated. -Icy Version 1.1.1, 11-NOV-2008, EDW (JPL) Edits to header; Abstract now states that this routine is deprecated. -Icy Version 1.1.0, 18-JUL-2005, EDW (JPL) Added capability to process vector 'et' and 'spoint' as inputs returning vectors 'dist', 'phase', 'solar', and 'emissn' as outputs. -Icy Version 1.0.0, 16-JUN-2003, EDW (JPL) ## Index_EntriesDEPRECATED illumination angles DEPRECATED lighting angles DEPRECATED phase angle DEPRECATED emission angle DEPRECATED solar incidence angle |

Wed Apr 5 17:58:01 2017