REVISIONS · SEE_ALSO
mscgetcatalog -- Get coordinates from a Web server covering mosaic exposures
MSCGETCATALOG is a task for getting coordinates and magnitudes from Web-based catalog servers. The task returns a text file of coordinates and magnitudes for a field centered on the specified mosaic exposure(s).
mscgetcatalog input output
- List of mosaic exposures.
- Output text file containing catalog coordinates and magnitudes.
- magmin = 0., magmax = 25.
- Range of magnitudes to select from the catalog.
- catalog = "NOAO:USNO-A2"
- Catalog to be used. With IRAF V2.11 and earlier the choices are:
- The USNO A2 catalog using a server from NOAO.
- The USNO A2 catalog using a server from the CADC.
With IRAF V2.12 the catalogs supported by the astcat package may also be used. For a list of catalogs use the command:
cl> aclist * verbose-
- rmin = 21.
- Minimum radius in arc minutes from the center of the input exposures to include in the output file. The actual radius used is the maximum of this parameter and the maximum radius to the corners of all the input extensions.
Mscgetcatalog is a task for getting coordinates and magnitudes from Web-based catalog servers. This requires that you can make http requests from the system where this task is executed. Proxy servers are not supported. Note that if the server does not respond this task may not return and would need to be interupted.
Mscgetcatalog returns a text file, specified by the output parameter, of coordinates and magnitudes for a field centered on the mosaic exposure(s), specified by the input . This requires that the mosaic exposures have an approximate world coordinate system (WCS). The catalog of sources is generally used to calibrate the WCS provided there is sufficient overlap between the field and the approximate WCS. This file can be used with various mscred tasks such as msccmatch , mscimatch , msczero , and msctvmark .
Currently all coordinates, input and output, are J2000.
The task msccmatch may execute this task to generate the coordinates to use by specifying
!mscgetcatalog $I $C
for the coords parameter. The "$I" field is replaced by the mosaic exposure being calibrated and "$C" is replaced by a temporary filename used by the task.
The center of the circular region to be extracted from the catalog is determined by the midpoint of the coordinates of all the extension corners in the list of input mosaic exposures. The maximum radius from this point to all the corners determines a minimum radius for the region. The rmin parameter may be used to force a minimum radius though if the radius including all the corners is larger then that radius is used.
The currently supported catalogs include approximate magnitudes. When magnitudes are available the magmin and magmax parameters may be used to restrict the output coordinates to a specified magnitude range.
The selection of catalogs in IRAF V2.11 and earlier is limited to "NOAO:USNO-A2" and "CADC:USNO-A2". In V2.12 the catalogs supported by the new catalog access package astcat may also be used. A list of catalogs may be obtained using the command:
cl> aclist * verbose-
The catalog names must be specified exactly as shown in the list.
1. This example illustrates getting coordinates for the brightest stars in an NOAO mosaic exposure using the default USNO-A2 server at NOAO. This specifies the output as "STDOUT" to print to the terminally. More commonly this would be a filename and the magnitude limit would include fainter stars.
ms> mscgetcat obj110 STDOUT magmax=11 15:23:19.94 -0:08:41.8 10.60 12.20 15:23:41.25 -0:16:17.8 8.60 11.60 15:24:57.69 -0:06:16.8 10.90 12.10 15:25:34.79 -0:01:02.8 10.60 12.30 15:25:40.38 -0:01:11.5 10.60 11.50 15:25:54.55 -0:17:02.8 10.40 11.80 15:22:58.95 0:05:55.9 10.40 13.90 15:23:05.07 0:04:17.0 11.00 12.10 15:24:09.96 0:03:04.2 11.00 11.90 15:26:00.73 0:17:46.3 8.60 9.40
2. To use the Guide Star Catalog 2 (in IRAF V2.12):
ms> mscgetcat obj110 STDOUT catalog=gsc2@stsci magmax=11 15:23:19.94 -0:08:41.8 10.60 12.20 15:23:41.25 -0:16:17.8 8.60 11.60 15:24:57.69 -0:06:16.8 10.90 12.10 15:25:34.79 -0:01:02.8 10.60 12.30 15:25:40.38 -0:01:11.5 10.60 11.50 15:25:54.55 -0:17:02.8 10.40 11.80 15:22:58.95 0:05:55.9 10.40 13.90 15:23:05.07 0:04:17.0 11.00 12.10 15:24:09.96 0:03:04.2 11.00 11.90 15:26:00.73 0:17:46.3 8.60 9.40
- MSCGETCATALOG - V4.7: April, 2002
- Modified to allow use of the ASTCAT package which provides access to a larger variety of catalogs.
- MSCGETCATALOG - V4.0: August 22, 2000
- This task is new in this release.