| term_pl02 |
|
Table of contents
Procedure
term_pl02 ( Terminator using DSK type 2 plate model )
void term_pl02 ( SpiceInt handle,
ConstSpiceDLADescr * dladsc,
ConstSpiceChar * trmtyp,
ConstSpiceChar * source,
ConstSpiceChar * target,
SpiceDouble et,
ConstSpiceChar * fixref,
ConstSpiceChar * abcorr,
ConstSpiceChar * obsrvr,
SpiceInt npts,
SpiceDouble * trgepc,
SpiceDouble obspos [3],
SpiceDouble trmpts [][3],
SpiceInt pltids [] )
AbstractDeprecated: This routine has been superseded by the CSPICE routine termpt_c. This routine is supported for purposes of backward compatibility only. Compute a set of points on the umbral or penumbral terminator of a specified target body, where the target body's surface is represented by a triangular plate model contained in a type 2 DSK segment. Required_ReadingNAIF_IDS PCK SPK TIME KeywordsBODY GEOMETRY MATH Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- handle I DSK handle. dladsc I DLA descriptor of target body segment. trmtyp I Terminator type. source I Light source. target I Target body. et I Observation epoch. fixref I Body-fixed frame associated with target. abcorr I Aberration correction. obsrvr I Observer. npts I Number of points in terminator set. trgepc O Epoch associated with target center. obspos O Position of observer in body-fixed frame. trmpts O Terminator point set. pltids O DSK plate IDs of surface points. Detailed_Input
handle is the DAS file handle of a DSK file open for read
access. This kernel must contain a type 2 segment
that provides a plate model representing the entire
surface of the target body.
dladsc is the DLA descriptor of a DSK segment representing
the surface of a target body.
trmtyp is a string indicating the type of terminator to
compute: umbral or penumbral. The umbral terminator is
the boundary of the portion of the target surface in
total shadow. The penumbral terminator is the boundary
of the portion of the surface that is completely
illuminated. Note that in astronomy references, the
unqualified word "terminator" refers to the umbral
terminator. Here, the unqualified word refers to either
type of terminator.
To compute the terminator points, this routine first
computes a set of points on the terminator of the
indicated type on the surface of a reference ellipsoid
for the target body. Each such point defines the
direction of a ray emanating from the target center and
associated with a terminator point on the actual surface
defined by the plate model. The outermost surface
intercept of each such ray is a considered to be a
terminator point of the surface defined by the plate
model.
Possible values of `trmtyp' are
"UMBRAL"
"PENUMBRAL"
Case and leading or trailing blanks in `trmtyp' are
not significant.
source is the name of the body acting as a light source.
`source' 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 "SUN" and "10" are
legitimate strings that indicate the Sun is the light
source.
This routine assumes that a kernel variable
representing the light source's radii is present in
the kernel pool. Normally the kernel variable would
be defined by loading a PCK file.
The shape of the light source is always modeled as a
sphere, regardless of whether radii defining a
triaxial ellipsoidal shape model are available in the
kernel pool. The maximum radius of the body is used
as the radius of the sphere.
target is 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.
This routine assumes that a kernel variable representing
the target's radii is present in the kernel pool.
Normally the kernel variable would be defined by loading
a PCK file.
et is the epoch of participation of the observer,
expressed as ephemeris seconds past J2000 TDB: `et' is
the epoch at which the observer's position is
computed.
When aberration corrections are not used, `et' is also
the epoch at which the position and orientation of the
target body and position of the light source are
computed.
When aberration corrections are used, `et' is the epoch
at which the observer's position relative to the solar
system barycenter is computed; in this case the
position and orientation of the target body are
computed at et-lt or et+lt, where `lt' is the one-way
light time between the target body's center and the
observer, and the sign applied to `lt' depends on the
selected correction. See the description of `abcorr'
below for details.
fixref is the name of the reference frame relative to which
the output terminator points are expressed. This must
a body-centered, body-fixed frame associated with the
target. The frame's axes must be compatible with the
triaxial ellipsoidal shape model associated with the
target body (normally provide via a PCK): this
routine assumes that the first, second, and third
axis lengths correspond, respectively, to the x, y,
and z-axes of the frame designated by `fixref'.
`fixref' may refer to a built-in frame (documented in
the Frames Required Reading) or a frame defined by a
loaded frame kernel (FK).
The orientation of the frame designated by `fixref' is
evaluated at epoch of participation of the target
body. See the descriptions of `et' and `abcorr' for
details.
abcorr indicates the aberration correction to be applied
when computing the observer-target position, the
orientation of the target body, and the target-
source position vector. `abcorr' may be any of
the following.
"NONE" Apply no correction. Compute the
terminator points using the position
of the light source and target, and
the orientation of the target, at `et'.
Let `lt' represent the one-way light time between the
observer and the target body's center. The following
values of `abcorr' apply to the "reception" case in
which photons depart from the target body's center at
the light-time corrected epoch et-lt and *arrive* at
the observer's location at `et':
"LT" Correct for one-way light time (also
called "planetary aberration") using a
Newtonian formulation. This correction
yields the location of the terminator
points at the approximate time they
emitted photons arriving at the
observer at `et' (the difference between
light time to the target center and
light time to the terminator points
is ignored).
The light time correction uses an
iterative solution of the light time
equation. The solution invoked by the
"LT" option uses one iteration.
The target position as seen by the
observer, the position of the light
source as seen from the target at
et-lt, and the rotation of the target
body, are corrected for light time.
'LT+S' Correct for one-way light time and
stellar aberration using a Newtonian
formulation. This option modifies the
positions obtained with the "LT" option
to account for the observer's velocity
relative to the solar system
barycenter. This correction also
applies to the position of the light
source relative to the target. The
result is the apparent terminator as
seen by the observer.
"CN" Converged Newtonian light time
correction. In solving the light time
equation, the "CN" correction iterates
until the solution converges. The
position and rotation of the target
body and the position of the light
source relative to the target are
corrected for light time.
'CN+S' Converged Newtonian light time
and stellar aberration corrections.
obsrvr is the name of the observing body. This is 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.
npts is the number of terminator points to compute.
Detailed_Output
trgepc is the "target epoch." `trgepc' is defined as follows:
letting `lt' be the one-way light time between the
target center and observer, `trgepc' is either the
epoch et-lt or `et' depending on whether the requested
aberration correction is, respectively, for received
radiation or omitted. `lt' is computed using the
method indicated by `abcorr'.
`trgepc' is expressed as seconds past J2000 TDB.
obspos is the vector from the center of the target body at
epoch `trgepc' to the observer at epoch `et'. `obspos' is
expressed in the target body-fixed reference frame
`fixref', which is evaluated at `trgepc'.
`obspos' is returned to simplify various related
computations that would otherwise be cumbersome. For
example, the vector `xvec' from the observer to the
Ith terminator point can be calculated via the call
vminus_c ( trmpts[i], obspos, xvec );
The components of `obspos' are given in units of km.
trmpts is an array of points on the umbral or penumbral
terminator of the target, as specified by the input
argument `trmtyp'. The ith point is contained in the
array elements
trmpts[i][j], j = 0, 1, 2
As described above, each terminator point lies on a ray
emanating from the center of the target and passing
through a terminator point on the target's reference
ellipsoid. Each terminator point *on the reference
ellipsoid* is the point of tangency of a plane that is
also tangent to the light source. These associated
points of tangency on the light source have uniform
distribution in longitude when expressed in a
cylindrical coordinate system whose Z-axis is the
target-source vector. The magnitude of the separation in
longitude between the tangency points on the light
source is
2*Pi / npts
If the reference ellipsoid for the target is spherical,
the terminator points also are uniformly distributed in
longitude in the cylindrical system described above. If
the reference ellipsoid of the target is non-spherical,
the longitude distribution of the points generally is
not uniform.
The terminator points are expressed in the body-fixed
reference frame designated by `fixref'. Units are km.
pltids is an array of integer ID codes of the plates on which
the terminator points are located. The ith plate ID
corresponds to the ith terminator point. These ID codes can
be use to look up data associated with the plate, such
as the plate's vertices or outward normal vector.
`pltids' should be declared by the caller
SpiceInt pltids [npts];
ParametersNone. Exceptions
1) If the input frame name `fixref' cannot be mapped
to a frame ID code, the error SPICE(NOTRANSLATION) is
signaled.
2) If the target name `target' cannot be mapped to a body ID code,
the error SPICE(IDCODENOTFOUND) is signaled.
3) If the source name `source' cannot be mapped to a body ID
code, an error is signaled by a routine in the call tree of
this routine.
4) If the frame designated by `fixref' is not centered
on the target, the error SPICE(INVALIDFIXREF) is
signaled.
5) If the terminator type is not recognized, an error
is signaled by a routine in the call tree of
this routine.
6) If the set size `npts' is not at least 1, an error
is signaled by a routine in the call tree of
this routine.
7) If any of the reference ellipsoid's semi-axis lengths is
non-positive, an error is signaled by a routine in the
call tree of this routine.
8) If the light source has non-positive radius, an error
is signaled by a routine in the call tree of
this routine.
9) If the light source intersects the smallest sphere centered at
the origin and containing the ellipsoid, an error is signaled
by a routine in the call tree of this routine.
10) If radii for the target body or light source are not
available in the kernel pool, an error is signaled by
a routine in the call tree of this routine.
11) If radii are available but either body does not have three
radii, the error SPICE(INVALIDCOUNT) is signaled.
12) If any SPK look-up fails, an error is signaled by
a routine in the call tree of this routine.
13) If a DSK providing a DSK type 2 plate model has not been
loaded prior to calling term_pl02, an error is signaled by a
routine in the call tree of this routine.
14) If the segment associated with the input DLA descriptor is not
of data type 2, the error SPICE(WRONGDATATYPE) is signaled.
15) If a surface point cannot be computed because the ray
corresponding to a longitude/latitude pair fails to intersect
the target surface as defined by the plate model, an error is
signaled by a routine in the call tree of this routine.
16) If the DSK segment identified by `dladsc' is not for the
body identified by `target', the error SPICE(DSKTARGETMISMATCH)
is signaled.
17) If any input string pointer is null, the error
SPICE(NULLPOINTER) is signaled.
18) If any input string has length zero, the error
SPICE(EMPTYSTRING) is signaled.
Files
Appropriate DSK, SPK, PCK, and frame kernels must be loaded by the
calling program before this routine is called.
The following data are required:
- DSK data: a DSK file containing a plate model representing the
target body's surface must be loaded. This kernel must contain
a type 2 segment that contains data for the entire surface of
the target body.
- SPK data: ephemeris data for target, observer, and light
source must be loaded. If aberration corrections are used,
the states of all three objects relative to the solar system
barycenter must be calculable from the available ephemeris
data. Typically ephemeris data are made available by loading
one or more SPK files via furnsh_c.
- PCK data: triaxial radii for the target body and
the light source must be loaded into the kernel pool.
Typically this is done by loading a text PCK file via
furnsh_c.
- Further PCK data: rotation data for the target body must
be loaded. These may be provided in a text or binary PCK
file.
- Frame data: if a frame definition is required to convert
the observer and target states to the target body-fixed
frame designated by `fixref', that definition must be
available in the kernel pool. Typically the definitions of
frames not already built-in to SPICE are supplied by loading
a frame kernel.
In all cases, kernel data are normally loaded once per program
run, NOT every time this routine is called.
ParticularsIn this routine, we use the term "umbral terminator" to denote the curve usually called the "terminator": this curve is the boundary of the portion of the target body's surface that lies in total shadow. We use the term "penumbral terminator" to denote the boundary of the completely illuminated portion of the surface. Boundaries of illuminated regions on an arbitrary surface are often complicated point sets: boundaries of shadows of mountains and craters, if present, all contribute to the overall set. To make the terminator computation tractable, we simplify the problem by using a reference ellipsoid for guidance. We compute a set of terminator points on the reference ellipsoid for the target body, then use those points to define the latitudes and longitudes of terminator points on the surface defined by the specified triangular shape model. As such, the set of terminator points found by this routine is just an approximation. Below we discuss the computation of terminator points on the target body's reference ellipsoid. This routine assumes a spherical light source. Light rays are assumed to travel along straight lines; refraction is not modeled. Points on the reference ellipsoid at which the entire cap of the light source is visible are considered to be completely illuminated. Points on the ellipsoid at which some portion (or all) of the cap of the light source are blocked are considered to be in partial (or total) shadow. In general, the terminator on an ellipsoid is a more complicated curve than the limb (which is always an ellipse). Aside from various special cases, the terminator does not lie in a plane. However, the condition for a point X on the ellipsoid to lie on the terminator is simple: a plane tangent to the ellipsoid at X must also be tangent to the light source. If this tangent plane does not intersect the vector from the center of the ellipsoid to the center of the light source, then X lies on the umbral terminator; otherwise X lies on the penumbral terminator. Examples
The 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) Compute sets of umbral and penumbral terminator points on Phobos
as seen from Mars. Perform a consistency check using the solar
incidence angle at each point, where the solar incidence angle
is computed using both a reference ellipsoid and the actual
plate model surface and surface normal. We expect to see a
solar incidence angle of approximately 90 degrees. Since the
solar incidence angle is measured between the local outward
normal and the direction to the Sun, the solar incidence angle
at an umbral or penumbral terminator point should be,
respectively, greater than or less than 90 degrees by
approximately the angular radius of the Sun as seen from each
terminator point.
Use the meta-kernel shown below to load the required SPICE
kernels.
KPL/MK
File: term_pl02_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
--------- --------
mar097.bsp Mars satellite ephemeris
pck00010.tpc Planet orientation and
radii
naif0010.tls Leapseconds
\begindata
KERNELS_TO_LOAD = ( 'mar097.bsp',
'pck00010.tpc',
'naif0010.tls' )
\begintext
End of meta-kernel
Use the DSK kernel below to provide the plate model representation
of the surface of Phobos.
phobos_3_3.bds
Example code begins here.
/.
Program term_pl02_ex1
./
#include <stdio.h>
#include <math.h>
#include "SpiceUsr.h"
int main()
{
/.
Local parameters
./
#define FILSIZ 256
#define NPOINTS 3
#define NTYPES 2
#define TOL ( 1.e-12 )
#define CORLEN 15
#define TYPLEN 81
#define TIMLEN 41
/.
Local variables
./
SpiceBoolean found;
SpiceChar * abcorr = "LT+S";
SpiceChar dsk [ FILSIZ ];
SpiceChar * fixref = "IAU_PHOBOS";
SpiceChar meta [ FILSIZ ];
SpiceChar * trmtyp;
SpiceChar * trmtypes [ NTYPES ] =
{
"Umbral",
"Penumbral"
};
SpiceChar * obsrvr = "Mars";
SpiceChar * target = "Phobos";
SpiceChar * utcstr = "2007 FEB 9 00:00:00 UTC";
SpiceChar timstr [ TIMLEN];
SpiceDLADescr dladsc;
SpiceDouble delta;
SpiceDouble emissn;
SpiceDouble lt;
SpiceDouble obspos [3];
SpiceDouble phase;
SpiceDouble radius;
SpiceDouble solar;
SpiceDouble sunAngRad;
SpiceDouble sunPos [3];
SpiceDouble sunRadii [3];
SpiceDouble sunVec [3];
SpiceDouble trgepc;
SpiceDouble et;
SpiceDouble lat;
SpiceDouble lon;
SpiceDouble trmpts [NPOINTS][3];
SpiceInt handle;
SpiceInt i;
SpiceInt n;
SpiceInt typidx;
SpiceInt pltids [NPOINTS];
/.
Prompt for the name of a meta-kernel specifying
all of the other kernels we need. Load the
metakernel.
./
prompt_c ( "Enter meta-kernel name > ", FILSIZ, meta );
furnsh_c ( meta );
/.
Prompt for the name of the DSK to read.
./
prompt_c ( "Enter DSK name > ", FILSIZ, dsk );
/.
Open the DSK file for read access.
We use the DAS-level interface for
this function.
./
dasopr_c ( dsk, &handle );
/.
Begin a forward search through the
kernel, treating the file as a DLA.
In this example, it's a very short
search.
./
dlabfs_c ( handle, &dladsc, &found );
if ( !found )
{
/.
We arrive here only if the kernel
contains no segments. This is
unexpected, but we're prepared for it.
./
setmsg_c ( "No segments found in DSK file #.");
errch_c ( "#", dsk );
sigerr_c ( "SPICE(NODATA)" );
}
/.
If we made it this far, `dladsc' is the
DLA descriptor of the first segment.
Convert the observation time to seconds past J2000 TDB.
./
str2et_c ( utcstr, &et );
timout_c ( et,
"YYYY-MON-DD "
"HR:MN:SC.### ::TDB(TDB)",
TIMLEN,
timstr );
printf ( "\n\n"
" Observer: %s\n"
" Target: %s\n"
" Observation epoch: %s\n"
" Aberration correction: %s\n"
" Body-fixed frame: %s\n",
obsrvr,
target,
timstr,
abcorr,
fixref );
/.
Look up the radii of the Sun. We'll use these as
part of a computation to check the solar incidence
angles at the terminator points.
./
bodvrd_c ( "SUN", "RADII", 3, &n, sunRadii );
/.
Now compute grids of terminator points using both
terminator types.
./
for ( typidx = 0; typidx < NTYPES; typidx++ )
{
/.
Select the terminator type.
./
trmtyp = trmtypes [typidx];
printf ( "\n"
" Terminator type: %s\n", trmtyp );
/.
Compute the terminator point set.
./
term_pl02 ( handle, &dladsc, trmtyp, "Sun",
target, et, fixref, abcorr,
obsrvr, NPOINTS, &trgepc, obspos,
trmpts, pltids );
/.
Display the terminator points.
./
for ( i = 0; i < NPOINTS; i++ )
{
printf ( "\n" );
reclat_c ( trmpts[i], &radius, &lon, &lat );
printf (
" Terminator point %d:\n"
" Radius (km): %f\n"
" Planetocentric longitude (deg): %f\n"
" Planetocentric latitude (deg): %f\n"
" Plate ID: %d\n",
(int)i,
radius,
lon * dpr_c(),
lat * dpr_c(),
(int)pltids[i] );
/.
Compute the angular radius of the Sun as seen from
the current terminator point. Subtracting (adding)
this value from (to) the solar incidence angle for
umbral (penumbral) terminator points should yield a
value close to 90 degrees. This provides a sanity
check on the locations of the terminator points.
First find the position of the Sun relative to the
target's center at the light time corrected epoch
trgepc.
./
spkpos_c ( "Sun", trgepc, fixref,
abcorr, target, sunPos, < );
vsub_c ( sunPos, trmpts[i], sunVec );
sunAngRad = asin ( sunRadii[0] / vnorm_c(sunVec) );
/.
Compute the delta by which we adjust the solar
incidence angles.
./
if ( eqstr_c( trmtyp, "umbral" ) )
{
delta = -sunAngRad;
}
else
{
delta = sunAngRad;
}
/.
Compute the illumination angles using an ellipsoidal
representation of the target's surface. The role of
this representation is to provide an outward surface
normal.
./
illum_c ( target, et, abcorr,
obsrvr, trmpts[i], &phase,
&solar, &emissn );
printf (
" "
"Solar incidence angle derived using\n"
" "
" - an ellipsoidal reference surface (deg):"
" %f\n",
solar * dpr_c() );
printf (
" "
" > adjusted for Solar angular radius (deg):"
" %f\n",
(solar+delta) * dpr_c() );
/.
Compute the illumination angles at the terminator point
using the actual plate model surface normal.
./
illum_pl02 ( handle, &dladsc, target, et,
abcorr, obsrvr, trmpts[i],
&phase, &solar, &emissn );
printf (
" "
" - plate model's surface and normal vector (deg):"
" %f\n",
solar * dpr_c() );
}
}
printf ( "\n" );
/.
Close the kernel. This isn't necessary in a stand-
alone program, but it's good practice in subroutines
because it frees program and system resources.
./
dascls_c ( handle );
return ( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, using the meta-kernel file named term_pl02_ex1.tm and
the DSK file named phobos_3_3.bds, the output was:
Enter meta-kernel name > term_pl02_ex1.tm
Enter DSK name > phobos_3_3.bds
Observer: Mars
Target: Phobos
Observation epoch: 2007-FEB-09 00:01:05.184 (TDB)
Aberration correction: LT+S
Body-fixed frame: IAU_PHOBOS
Terminator type: Umbral
Terminator point 0:
Radius (km): 12.111257
Planetocentric longitude (deg): 34.584501
Planetocentric latitude (deg): -0.001298
Plate ID: 200400
Solar incidence angle derived using
- an ellipsoidal reference surface (deg): 90.182028
> adjusted for Solar angular radius (deg): 90.000000
- plate model's surface and normal vector (deg): 90.240660
Terminator point 1:
Radius (km): 9.774665
Planetocentric longitude (deg): -143.659941
Planetocentric latitude (deg): 43.397190
Plate ID: 156958
Solar incidence angle derived using
- an ellipsoidal reference surface (deg): 90.182028
> adjusted for Solar angular radius (deg): 90.000000
- plate model's surface and normal vector (deg): 87.138686
Terminator point 2:
Radius (km): 11.500619
Planetocentric longitude (deg): -146.128151
Planetocentric latitude (deg): -43.082379
Plate ID: 25552
Solar incidence angle derived using
- an ellipsoidal reference surface (deg): 90.182029
> adjusted for Solar angular radius (deg): 90.000000
- plate model's surface and normal vector (deg): 91.404206
Terminator type: Penumbral
Terminator point 0:
Radius (km): 12.859785
Planetocentric longitude (deg): -145.415505
Planetocentric latitude (deg): 0.001299
Plate ID: 86763
Solar incidence angle derived using
- an ellipsoidal reference surface (deg): 89.817972
> adjusted for Solar angular radius (deg): 90.000000
- plate model's surface and normal vector (deg): 89.055489
Terminator point 1:
Radius (km): 10.327413
Planetocentric longitude (deg): 36.340069
Planetocentric latitude (deg): -43.397192
Plate ID: 76977
Solar incidence angle derived using
- an ellipsoidal reference surface (deg): 89.817972
> adjusted for Solar angular radius (deg): 90.000000
- plate model's surface and normal vector (deg): 77.351956
Terminator point 2:
Radius (km): 10.086025
Planetocentric longitude (deg): 33.871859
Planetocentric latitude (deg): 43.082380
Plate ID: 282136
Solar incidence angle derived using
- an ellipsoidal reference surface (deg): 89.817972
> adjusted for Solar angular radius (deg): 90.000000
- plate model's surface and normal vector (deg): 88.997322
Restrictions1) This routine models light paths as straight lines. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) Version
-CSPICE Version 1.1.0, 26-OCT-2021 (JDR)
Changed the argument names "npoints" and "plateIDs" to "npts" and
"pltids" for consistency with other routines.
Edited the header to comply with NAIF standard.
Index lines now state that this routine is deprecated.
-CSPICE Version 1.0.0, 22-FEB-2017 (NJB)
Include file references have been updated. Integer output
format in the example program has been updated.
An error in the Detailed_Output header section was corrected.
The text now states that the central axis of the cylindrical
system is the target-source vector.
29-APR-2014 (NJB)
Bug fix: added chkout_c call after call to edterm_.
Bug fix: corrected module name used in check-in and
check-out calls.
Bug fix: added error handling for null input string
pointers and empty strings.
Changed name of argument `fixfrm' to `fixref'.
14-MAY-2010 (NJB)
Updated kernels in example program.
12-FEB-2010 (NJB)
This routine now calls the CSPICE routine
edterm_
instead of
edterm_pl02__
This routine was updated to include
SpiceDSK.h
pl02.h
The header example has been updated to use current
planetary and satellite SPK files.
09-FEB-2007 (NJB)
Index_EntriesDEPRECATED find terminator on plate model DEPRECATED find terminator on triangular shape model DEPRECATED find umbral terminator on plate model DEPRECATED find umbral terminator on plate model DEPRECATED find penumbral terminator on plate model DEPRECATED find penumbral terminator on shape model |
Fri Dec 31 18:41:14 2021