Program: PLATE Purpose: snips raw data from tape(s) to custom plate Category: IRAS Author: Do Kester File: plate.src Keywords: INSTRUME= give instrument identification [] a combination of observation mode SURVEY SPLINE AO PO FLASH UNKNOWN and band number 12 25 60 100 LRS BPHF 1 2 3 4 ( 2 letters suffice ) PO is an alias for AO; AOs, POs and UNKNOWNs are collectively known as pointed observations. CENTER= give the central longitude and latitude of the plate SIZE= give (long. and lat.) size of the plate [1.0] COOR= give coordinate system [EQUATORIAL 2000] standard coordinate systems are: EQUATORIAL 2000.0 GALCTIC ECLIPTIC 2000.0 SUPERGALACTIC SUNREFERENCED sun at lambda=0.0 ( 3 letters suffice ) If the second item cannot be read the system will ask EPOCH= give epoche pertaining to COOR [2000.0] If the coordinate system is unknown the program asks whether you want to make a new system, if not you get a retry. *** CONFIRM= I want a new system [yes] If yes, the system asks for 3 angles and a reference system: *** POLEDIST= give distance between the poles in degrees [0.0] of the reference coordinate system and the coordinate system to be defined *** REFNODE= give long. of the asc. node in the ref. system [0.0] *** NEWNODE= give long. of the asc. node in the new system [0.0] *** COOR= give ref. coordinate system [EQUATORIAL 2000] IRSET= give set name to write to [no snip action] If the set already exists the program asks for STATUS= it already exists: choose merge, error or [overwrite] ( 1 letter suffices ) OBJECT= give name of the object [no name] OBSERVER= give name of the observer [no name] *** FLASHTIMES= number of secs to cut from the beginning and end of the scans. [32,20] In case of AO or Unknown the flashtimes are set to 0,0 by default. *** SOPATT= select only this sop/att combination Zero, one or two items can be given here. Depending on the selected instrument the following happens: instrume items in SOPATT= survey 0 normal case, no list is displayed select all scans overlapping the plate 1 display list of all overlapping scans request further selection with SOPATT= 2 no list is displayed select only the scan indicated with SOPATT= AO or 0 display list of all overlapping scans unknown select the first scan in the list 1 display list of all overlapping scans ask again for one SOPATT= 2 no list is displayed select only the scan indicated with SOPATT= Note that survey scans are snipped to the plate size; Use MINTICK= to get a full sized scan. Note also that the pointed observations are NOT snipped at all. Except for the display of the list the central position is irrelevant. *** SKIPTICK= skip snips with a overlap length shorter than [2] ticks *** MINTICK= make snips of a minimum length of [2] ticks This action is performed after the skip, so that one can throw away too short snips and make all others of a minimum length, with the selected area as much as possible in the center of the snip. Full scans are selected with MINTICK=6000 (or larger). NB. Due to flashes at begin or end of a scan some snips may actually turn out shorter. Description: PLATE builds an IRAS Data Structure (IRDS) for a particular area (custom plate) from the optical disc server. For the definition of an IRDS see IRAS User Manual SWG-ROG 90 003. The custom plate is defined by an area on the sky: keyword CENTER, SIZE and COOR, and keyword INSTRUME which defined the observation mode and the band number. Only scan(snip)s which pertain to the same area and instrument can be stored in the same IRDS. The area is called the custom plate. The unsnipped data are stored on digital optical discs which reside in a jukebox like server. With IRSET the name of the IRDS is queried. If IRSET is presented with an existing IRDS it is asked whether it is an error, or to overwrite it, or to merge the new data with this existing one. In this way an existing IRDS can be enlarged. Note that if this IRDS is on quite a different location as the one requested by CENTER, SIZE and COOR, two unrelated custom plates are stored in one IRDS. It is not clear what the use of such a set is. Where the beginning or the end of a scan falls within the custom plate the snip starts later or ends earlier by a number of seconds given with FLASHTIMES. The first number pertains to the beginning and the second to the ending of the scans. In this way the flashes at the start and end of each scan are avoided. AO's have no flashes at the beginning and end of the scans. For them the FLASHTIMES are by default 0. When sop/att selection is asked either by default for pointed observations or if the keywords SOPATT received some input ( the answer 0 will do the trick ) a list of sop/att combinations which are present in the selected area is made and the user is asked to select from this list. Selection can only be done in increasing order. Some data around data outages were discovered to be corrupt. Those parts are put to the GIPSY blank value. Updates: 900105 DK, documentation only 900327 DK, creation of code 910308 DK, add noise estimate on snip-detector level 910912 DK, adapted for the optical disc server 920218 DK, blank out corrupt data 920225 DK, list available sop-att's if sop/att selection 920225 DK, put flashtimes=0 0 by default for AO's 920226 DK, SCANTYPE is added to the header at snip-level 920227 DK, proper handling of crippled irds's 930330 DK, add UNKNOWNs and PO as alias for AO 931019 DK, allow single scan selection 940419 DK, repaired obscure bug in string handling