MOS Fiber Configuration Data File

The automated fiber assignment code (assign) produces a file that describes the fiber assignments. This file is read by SCRAP. In a sense this serves as a more immediately human readable version of the FITS ASCII tables. In the long run the possibility that SCRAP might directly use the FITS tables from assign should be considered.

The PROPOSED file format

This follows the general guidelines and should be compared with the format currently in use.

The Magic Number

The first line of the file must be

#@ MOS Pconfig File

Keyword/Value Pairs

The keywords in the header of this table include, but are not limited to, the following:

DATE:

# Various keywords describing the field center
RA_PNT:
DEC_PNT:
HA_PNT:
RADECPNT: FK5
EQUINPNT:
MJD-PNT:
DATE_PNT:

# Various keywords describing the coordinate system below
RADECSYS: REFGAPPT
MJD_WCS:
REFWAVEL:

# Keywords that keep the old input code in SCRAP happy
NUM_FIBERS:
NUM_OBJECTS:

NUM_FIBERS and NUM_OBJECTS are not included in the FITS files and are not defined in the data dictionary. They are required by the design of the SCRAP code.

NUM_OBJECTS is the total number of fibers in the table which are assigned to objects; i.e., SCRAP will have to move NUM_OBJECTS fibers away from their park locations.

NUM_FIBERS is the total number of fibers in the table. Ron Wurtz believes that each fiber which has a button must appear in the table; he is not sure whether or not SCRAP needs to see all 101 entries implied by the number of pivots.

The Magic Number starting the table

The table begins after a line which reads

#@ MOS Pconfig Table

Contents of the table

Each line of the table shall consist of these entries in this order:

PIVOTID SLITID FIBERID FIBSTAT BTN_POSX BTN_POSY PIV_POSX PIV_POSY UNAME MAG RA DEC PRIO

The current version of SCRAP requires that the fibers be presented in an ordered fashion. There must first be NUM_OBJECTS fibers which are assigned to objects elsewhere than their park locations. There must be a total of NUM_FIBERS entries in the table.

The data dictionary contains definitions of each of these entries.

For historical reasons the output formats of these columns will differ from those in the FITS file. X & Y Positions shall be given in micrometers. RA and DEC shall be given as sexagesimal strings, with RA in hours.

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Steve Allen <sla@ucolick.org>