cspice_subsol |
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## AbstractCSPICE_SUBSOL determines the coordinates of the sub-solar point on a target body as seen by a specified observer at a specified epoch, optionally corrected for planetary (light time) and stellar aberration. Deprecated: This routine has been superseded by the routine cspice_subslr. This routine is supported for purposes of backward compatibility only. ## I/OGiven: method the name for the computation method to use. [1,c1] = size(method); char = class(method) or [1,1] = size(method); cell = class(method) The choices are: 'Near point' The sub-solar point is defined as the nearest point on the target to the sun. 'Intercept' The sub-observer point is defined as the target surface intercept of the line containing the target's center and the sun's center. In both cases, the intercept computation treats the surface of the target body as a triaxial ellipsoid. The ellipsoid's radii must be available in the kernel pool. Neither case nor white space are significant in method. For example, the string ' NEARPOINT' is valid. target the 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. [1,c2] = size(target); char = class(target) or [1,1] = size(target); cell = class(target) This routine assumes that the target body is modeled by a tri-axial ellipsoid, and that a PCK file containing its radii has been loaded into the kernel pool via cspice_furnsh. et the value(s) for ephemeris time expressed as ephemeris seconds past J2000 at which the sub-solar point on the target body is to be computed. [1,n] = size(et); double = class(et) abcorr the aberration corrections to apply when computing the observer-target state. [1,c3] = size(abcorr); char = class(abcorr) or [1,1] = size(abcorr); cell = class(abcorr) 'abcorr' may be any of the following. 'NONE' Apply no correction. Return the geometric sub-solar point on the target body. 'LT' Correct for planetary (light time) aberration. Both the state and rotation of the target body are corrected for one way light time from target to observer. The state of the sun relative to the target is corrected for one way light from the sun to the target; this state is evaluated at the epoch obtained by retarding et by the one way light time from target to observer. 'LT+S' Correct for planetary (light time) and stellar aberrations. Light time corrections are the same as in the 'LT' case above. The target state is additionally corrected for stellar aberration as seen by the observer, and the sun state is corrected for stellar aberration as seen from the target. 'CN' Converged Newtonian light time correction. This option produces a solution that is at least as accurate at that obtainable with the 'LT' option. Whether the 'CN' solution is substantially more accurate depends on the geometry of the participating objects and on the accuracy of the input data. In all cases this routine will execute more slowly when a converged solution is computed. See the section titled "The Computation of Light Time" in the SPK Required Reading document spk.req for details. 'CN+S' Converged Newtonian light time and stellar aberration corrections. Light time and stellar aberration corrections are applied as in the 'LT+S' case. obsrvr the name of the observing body. This is typically a spacecraft, the earth, or a surface point on the earth. [1,c4] = size(obsrvr); char = class(obsrvr) or [1,1] = size(obsrvr); cell = class(obsrvr) `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. the call: spoint = ## 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. % % Find the sub solar position on the earth as seen from the moon at % at epoch JAN 1, 2006 using the 'near point' then the 'intercept' % options. Apply light time correction to return apparent position. % % Load the meta kernel listing the needed SPK, PCK, LSK % kernels. % cspice_furnsh( 'standard.tm' ) et = cspice_str2et( 'JAN 1, 2006' ); % % First use option 'Near Point' % point1 = ## Particulars
## Required ReadingFor important details concerning this module's function, please refer to the CSPICE routine subsol_c. MICE.REQ FRAMES.REQ PCK.REQ SPK.REQ TIME.REQ ## Version-Mice Version 1.0.4, 30-OCT-2014, EDW (JPL) Edited I/O section to conform to NAIF standard for Mice documentation. -Mice Version 1.0.3, 23-JUN-2014, NJB (JPL) Updated description of converged Newtonian light time correction. -Mice Version 1.0.2, 18-MAY-2010, BVS (JPL) Index line now states that this routine is deprecated. -Mice Version 1.0.1, 11-NOV-2008, EDW (JPL) Edits to header; Abstract now states that this routine is deprecated. -Mice Version 1.0.0, 07-MAR-2007, EDW (JPL) ## Index_EntriesDEPRECATED sub-solar point |

Wed Apr 5 18:00:35 2017