; INDXH ;--------------------------------------------------------------- ;! writes index file describing contents of UV data base ;# TASK CALIBRATION SINGLEDISH ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 1997 ;; Associated Universities, Inc. Washington DC, USA. ;; ;; This program is free software; you can redistribute it and/or ;; modify it under the terms of the GNU General Public License as ;; published by the Free Software Foundation; either version 2 of ;; the License, or (at your option) any later version. ;; ;; This program is distributed in the hope that it will be useful, ;; but WITHOUT ANY WARRANTY; without even the implied warranty of ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;; GNU General Public License for more details. ;; ;; You should have received a copy of the GNU General Public ;; License along with this program; if not, write to the Free ;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge, ;; MA 02139, USA. ;; ;; Correspondence concerning AIPS should be addressed as follows: ;; Internet email: aipsmail@nrao.edu. ;; Postal address: AIPS Project Office ;; National Radio Astronomy Observatory ;; 520 Edgemont Road ;; Charlottesville, VA 22903-2475 USA ;----------------------------------------------------------------------- INDXH LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC INDXH Task to index a uv data base. INNAME Input UV file name (name) INCLASS Input UV file name (class) INSEQ 0.0 9999.0 Input UV file name (seq. #) INDISK 0.0 9.0 Input UV file disk unit # CPARM -1.0 9999.0 1=> max. time gap (min). 0 => 10 min 2=> max scan length (min). 0 => 60 min 3=> CL/CS entry interval in minutes. 0 => 5 min, < 0 => don't create a new table. 4=> VLBA only: recalculate CL entry group delays using IM table data. 0 => No recalculation, 1 => Recalculate delays. 5=> single-dish only: maximum "antenna"/"beam" number in data set (if no AN) ---------------------------------------------------------------- INDXH Type: Task Use: Creates an index (NX) table and indexes the uv data file. A maximum time gap and a maximum scan length may be specified. If no CL (CS for single-dish data) table is present, an empty one is (optionally) created. Data must be in T* order and may be in single-source or multi-source format. The NX table is used to speed access to uv data sets by giving offsets into the file for time ranges, source numbers, and the like. CL and CS tables, version 1, are the basis for interferometer and single-dish calibration. Usually they are created as the data are read in (for the VLA with FILLM, for the VLBA with FITLD, and for some single-dish data sets with SD2UV) and should not be replaced. If they are lost or were never created (i.e. OTFUV in OTF 12m data), then INDXH may be used to create them if they are needed. Adverbs: INNAME.....Input UV file name (name). Standard defaults. INCLASS....Input UV file name (class). Standard defaults. INSEQ......Input UV file name (seq. #). 0 => highest. INDISK.....Disk drive # of input UV file. 0 => any. CPARM......CPARM(1) = max. gap in data in minutes. If a gap longer than CPARM(1) is found, a new index record will be started. 0 => 10 min. CPARM(2) = max. length (in minutes) of a scan. If an uninterrupted section of data on the same source longer than CPARM(2) is found, a new index record will be started. 0 => 60 min. [For single-dish data, a "SCAN" random parameter, if present, will also be used to determine scan boundaries. In this case, set CPARM(2) to a high value unless you want to subdivide scans.] CPARM(3) = interval of CL (CS for single-dish) table entries in minutes. If there are no CL/CS tables associated with the data a new one will be created with null (1's and 0's) entries. 0 => 5 min. If CPARM(3) < 0, then a new CL or CS table will not be created. CPARM(4) = VLBA-only delay recalculation option. When recreating a CL table, the geometric group delays used by the VLBA correlator are recalculated using information from the IM table. 0 => No recalculation, 1 => recalculate delays. CPARM(5) = single-dish only: the maimum antenna or beam number actually in the data set. This is used to cover up for absent antenna (AN) tables only. ----------------------------------------------------------------