Table of contents
CSPICE_SPKOBJ finds the set of ID codes of all objects in a specified SPK
file.
Given:
spkfnm the name of an SPK file.
help, spkfnm
STRING = Scalar
ids an initialized SPICE set data structure.
help, ids
STRUCT = cspice_celli(N)
`ids' optionally may contain a set of ID codes on input; on
output, the data already present in `ids' will be combined with
ID code set found for the file `spkfnm'.
If `ids' contains no data on input, its size and
cardinality still must be initialized.
the call:
cspice_spkobj, spkfnm, ids
returns:
ids a SPICE set data structure which contains the union of its
contents upon input with the set of ID codes of each object for
which ephemeris data are present in the indicated SPK file.
help, ids
STRUCT = cspice_celli(N)
The elements of SPICE sets are unique; hence each ID code in
`ids' appears only once, even if the SPK file contains multiple
segments for that ID code.
See the -Examples section below for a complete example
program showing how to retrieve the ID codes from `ids'.
The user must create `ids' using cspice_celli. (Note:
a set is a type of cell).
None.
Any numerical results shown for these examples may differ between
platforms as the results depend on the SPICE kernels used as input
and the machine specific arithmetic implementation.
1) Use a simple function to display the SPK IDs found in an SPK or set of
SPKs, and the time coverage of the data corresponding to those IDs.
This example calls both cspice_spkobj and cspice_spkcov. In practice,
algorithms using cspice_spkobj will also use cspice_spkcov and
vice-versa.
Use the LSK kernel below to load the leap seconds and time
constants required for the time conversions.
naif0012.tls
Example code begins here.
PRO spkobj_ex1, spknam
;;
;; From a given SPK file, retrieve the list of objects listed
;; in the file then retrieve the time coverage for each object.
;;
;; Local parameters...
;;
MAXIV = 1000
WINSIZ = 2 * MAXIV
TIMLEN = 51
MAXOBJ = 1000
LSK = 'naif0012.tls'
;;
;; Local variables
;;
cover = cspice_celld( WINSIZ )
ids = cspice_celli( MAXOBJ )
;;
;; Note, neither cspice_spkcov or cspice_spkobj requires this
;; kernel to function. We need the data for output time
;; conversion.
;;
cspice_furnsh, LSK
;;
;; Find the set of objects in the SPK file.
;;
for i = 1, n_elements(spknam) do begin
cspice_spkobj, spknam[i-1], ids
endfor
;;
;; We want to display the coverage for each object. Loop over
;; the contents of the ID code set, find the coverage for
;; each item in the set, and display the coverage.
;;
for i=0, cspice_card( ids ) - 1 do begin
;;
;; Find the coverage window for the current object, 'i'.
;; Empty the coverage window each time
;; so we don't include data for the previous object.
;;
obj = ids.base[ ids.data + i ]
cspice_scard, 0L, cover
for k = 1, n_elements(spknam) do begin
cspice_spkcov, spknam[k-1], obj, cover
endfor
;;
;; Get the number of intervals in the coverage window.
;;
niv = cspice_card( cover ) / 2
;;
;; Display a simple banner.
;;
print, "========================================"
print, "Coverage for object:", obj
;;
;; Convert the coverage interval start and stop times to TDB
;; calendar strings.
;;
for j=0, niv-1 do begin
;;
;; Get the endpoints of the jth interval.
;;
cspice_wnfetd, cover, j, b, e
;;
;; Convert the endpoints to TDB calendar
;; format time strings and display them.
;; Pass the endpoints in an array, [b,e],
;; so cspice_timout returns an array of time
;; strings.
;;
cspice_timout, [b,e], $
"YYYY MON DD HR:MN:SC.### (TDB) ::TDB", $
TIMLEN ,$
timstr
print, "Interval: ", j
print, "Start : ", timstr[0]
print, "Stop : ", timstr[1]
print
endfor
endfor
;;
;; Empty the kernel pool.
;;
cspice_kclear
END
When this program was executed on a Mac/Intel/IDL8.x/64-bit
platform, with the following variable as input
spknam = ['sat393.bsp', 'ura112.bsp']
the output was:
========================================
Coverage for object: 3
Interval: 0
Start : 1900 JAN 01 00:00:41.183 (TDB)
Stop : 2099 DEC 24 00:01:07.183 (TDB)
========================================
Coverage for object: 6
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 7
Interval: 0
Start : 1900 JAN 01 00:00:41.183 (TDB)
Stop : 2099 DEC 24 00:01:07.183 (TDB)
========================================
Coverage for object: 10
Interval: 0
Start : 1900 JAN 01 00:00:41.183 (TDB)
Stop : 2099 DEC 24 00:01:07.183 (TDB)
========================================
Coverage for object: 399
Interval: 0
Start : 1900 JAN 01 00:00:41.183 (TDB)
Stop : 2099 DEC 24 00:01:07.183 (TDB)
========================================
Coverage for object: 610
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 611
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 612
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 613
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 614
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 615
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 616
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 617
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 632
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 633
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 634
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
Stop : 2050 JAN 01 00:01:08.183 (TDB)
========================================
Coverage for object: 649
Interval: 0
Start : 1950 JAN 01 00:00:41.183 (TDB)
[...]
Warning: incomplete output. Only 100 out of 174 lines have been
provided.
2) When Example #1 was executed on a Mac/Intel/IDL8.x/64-bit
platform, with the following variable as input
spknam = [ 'mgs_ext12_ipng_mgs95j.bsp', 'mgs_ext26_ipng_mgs95j.bsp' ]
the output was:
========================================
Coverage for object: -94
Interval: 0
Start : 2003 JUL 23 00:00:00.000 (TDB)
Stop : 2003 OCT 15 01:00:00.000 (TDB)
Interval: 1
Start : 2006 OCT 11 00:00:00.000 (TDB)
Stop : 2006 NOV 08 01:00:00.000 (TDB)
This routine provides an API via which applications can determine
the set of objects for which there are ephemeris data in a
specified SPK file.
1) If the input file has transfer format, the error
SPICE(INVALIDFORMAT) is signaled by a routine in the call tree
of this routine.
2) If the input file is not a transfer file but has architecture
other than DAF, the error SPICE(INVALIDARCHTYPE) is signaled
by a routine in the call tree of this routine.
3) If the input file is a binary DAF file of type other than SPK,
the error SPICE(INVALIDFILETYPE) is signaled by a routine in
the call tree of this routine.
4) If the SPK file cannot be opened or read, an error is signaled
by a routine in the call tree of this routine.
5) If the size of the output set argument `ids' is insufficient to
contain the actual number of ID codes of objects covered by
the indicated SPK file, an error is signaled by a routine in
the call tree of this routine.
6) If any of the input arguments, `spkfnm' or `ids', is
undefined, an error is signaled by the IDL error handling
system.
7) If any of the input arguments, `spkfnm' or `ids', is not of
the expected type, or it does not have the expected dimensions
and size, an error is signaled by the Icy interface.
None.
1) If an error occurs while this routine is updating the set
`ids', the set may be corrupted.
CELLS.REQ
DAF.REQ
ICY.REQ
SETS.REQ
SPK.REQ
NAIF_IDS.REQ
None.
N.J. Bachman (JPL)
J. Diaz del Rio (ODC Space)
E.D. Wright (JPL)
-Icy Version 1.1.0, 24-NOV-2021 (JDR)
Changed the input argument name "spk" to "spkfnm" for consistency
with other routines.
Edited the header to comply with NAIF standard.
Added -Parameters, -Exceptions, -Files, -Restrictions,
-Literature_References and -Author_and_Institution sections.
Removed reference to the routine's corresponding CSPICE header from
-Abstract section.
Added arguments' type and size information in the -I/O section.
-Icy Version 1.0.3, 05-JAN-2016 (EDW)
Modified example code to use arrays of SPKs an inputs.
-Icy Version 1.0.2, 30-NOV-2007 (NJB) (EDW)
Corrected bug in the -Examples section program:
program now empties the coverage window prior to collecting
data for the current object. Updated example to
use cspice_wncard rather than cspice_card.
-Icy Version 1.0.1, 26-JAN-2006 (EDW)
Corrected minor typo in description of 'ids' variable
-Icy Version 1.0.0, 30-DEC-2004 (EDW)
find id codes of ephemeris objects in SPK file
find id codes of bodies in SPK file
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