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 Deprecated: This routine has been superseded by the routine cspice_ilumin.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. ## I/OGiven: target the name of the target body. 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. [1,c1] = size(target); char = class(target) or [1,1] = size(target); cell = class(target) The target and observer define a state vector whose position component points from the observer to the target. Case and leading or trailing blanks are not significant in the string 'target'. et the ephemeris time(s) at which to compute the apparent illumination angles at the specified surface point on the target body, as seen from the observing body. [1,n] = size(et); double = class(et) abcorr describes the aberration corrections to apply to the state evaluations to account for one-way light time and stellar aberration. [1,c2] = size(abcorr); char = class(abcorr) or [1,1] = size(abcorr); cell = class(abcorr) This routine accepts the same aberration corrections as does the routine spkezr_c. See the header of spkezr_c for a detailed description of the aberration correction options. For convenience, the options are listed below: 'NONE' Apply no correction. 'LT' "Reception" case: correct for one-way light time using a Newtonian formulation. 'LT+S' "Reception" case: correct for one-way light time and stellar aberration using a Newtonian formulation. 'CN' "Reception" case: converged Newtonian light time correction. 'CN+S' "Reception" case: converged Newtonian light time and stellar aberration corrections. 'XLT' "Transmission" case: correct for one-way light time using a Newtonian formulation. 'XLT+S' "Transmission" case: correct for one-way light time and stellar aberration using a Newtonian formulation. 'XCN' "Transmission" case: converged Newtonian light time correction. 'XCN+S' "Transmission" case: converged Newtonian light time and stellar aberration corrections. The 'abcorr' string lacks sensitivity to case, and to embedded, leading and trailing blanks. obsrvr the name of the observing body, typically a spacecraft, the earth, or a surface point on the earth. 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. [1,c3] = size(obsrvr); char = class(obsrvr) or [1,1] = size(obsrvr); cell = class(obsrvr) Case and leading or trailing blanks are not significant in the string 'obsrvr'. spoint an 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'. [3,n] = size(spoint); double = class(spoint) 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 SPK kernel path-name to a string variable. % MGS = '/kernels/MGS/spk/spk_m_030102-030403_021004.bsp'; % % Define the start and stop time for the computations. % START_TIME = '1 Feb 2003'; STOP_TIME = '1 APR 2003'; % % Number of steps? % STEP = 75; % % Load the standard leapseconds and PCK kernels, and the MGS SPK % kernel. % cspice_furnsh( 'standard.tm' ) cspice_furnsh( MGS ) % % Convert the strings to ephemeris time J2000. % et_start = cspice_str2et( START_TIME ); et_stop = cspice_str2et( STOP_TIME ); % % Length of a step in seconds for STEP steps. % space = (et_stop - et_start)/STEP; % % Create a vector of ephemeris times. % et = [0:(STEP-1)]*space + et_start; % % 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. % [pos, alt] = cspice_subpt( 'Intercept', TARGET, et, CORRECT, OBSERVER ); [ phase, solar, emissn] = ## ParticularsNone. ## Required ReadingFor important details concerning this module's function, please refer to the CSPICE routine illum_c. MICE.REQ KERNEL.REQ NAIF_IDS.REQ SPK.REQ TIME.REQ ## Version-Mice Version 1.0.3, 18-NOV-2014, EDW (JPL) Edited I/O section to conform to NAIF standard for Mice documentation. -Mice Version 1.0.2, 18-MAY-2010, BVS (JPL) Index lines now state that this routine is deprecated. -Mice Version 1.0.1, 30-DEC-2008, EDW (JPL) Edits to header; Abstract now states that this routine is deprecated. Corrected misspellings. -Mice Version 1.0.0, 15-DEC-2005, EDW (JPL) ## Index_EntriesDEPRECATED illumination angles DEPRECATED lighting angles DEPRECATED phase angle DEPRECATED emission angle DEPRECATED solar incidence angle |

Wed Apr 5 18:00:32 2017