; UVADC ;--------------------------------------------------------------- ;! Fourier transforms and corrects a model and adds to uv data. ;# TASK UV AP ANALYSIS ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1997, 1999, 2001-2002, 2008-2009 ;; 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 ;----------------------------------------------------------------------- UVADC LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC UVADC Task to correct and add CLEAN components to uv data. INNAME Input UV file name (name) INCLASS Input UV file name (class) INSEQ 0.0 9999.0 Input UV file name (seq. #) INDISK Input UV file disk unit # NMAPS 0.0 4096.0 No. maps to use for model. CHANNEL -1.0 9999.0 Spectral channel (0=>all) Use 0 for continuum BIF 0.0 9999.0 First IF (0=>1) EIF 0.0 9999.0 Highest IF (0=>BIF to last) IN2NAME Cleaned map name (name) IN2CLASS Cleaned map name (class) IN2SEQ 0.0 9999.0 Cleaned map name (seq. #) IN2DISK Cleaned map disk unit # INVERS -1.0 46655.0 CC file version #. OUTNAME Output UV file name (name) OUTCLASS Output UV file name (class) OUTSEQ -1.0 9999.0 Output UV file name (seq. #) OUTDISK Output UV file disk unit #. BCOMP First CLEAN comp to sub. 1 per field. NCOMP Last CLEAN comp to sub. to use (0 => all) FLUX Lowest CC component used. CPARM (1) >0 => max. correct for bandwidth smearing (2) bandwidth corr. factor (3) frequency corr. factor FACTOR Factor times CLEAN fluxes. 0->1.0 add -1.0 subtract SMODEL Source model, 1=flux,2=x,3=y See HELP SMODEL for models. BADDISK Disks to avoid for scratch ---------------------------------------------------------------- UVADC Task: Fourier transforms a CLEAN point model and corrects for geometric distortions and adds to a uv data set. This task is designed for use to correct the effects of minor geometric distortions due to curvature of the sky and optionally (1) bandwidth smearing, (2) errors in the nominal bandwidth, and (3) errors in the nominal center frequency. It is mostly of use for snapshots with the VLA. If a correction for bandwidth smearing is requested then the correction factor for each component/visibility/frequency is limited to the range (0.98, 1.0 + 0.01*CPARM(1)) If the computed correction is outside of this range then 1.0 + 0.01*CPARM(1) is used. Note: this correction cannot recover badly smeared images and will amplify the noise on some baselines! If a correction is to be made to the nominal bandwidth to be used for the bandwidth smearing correction this can be passed as CPARM(2). A similar correction to the nominal center frequency (and thus the u, v and w) can be passed as CPARM(3). Model images made with both values of IMAGR's DO3DIMAG option are handled correctly, as are multi-scale images. Set NMAPS = NFIELD * NGAUSS. NOTE: this task does NOT apply flagging or calibration tables to the input UV data. Run SPLIT first if that operation is desired. 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. NMAPS......Number of image files to use for model. For multi-scale models, set NMAPS = NFIELD * NGAUSS to include the Clean components of the extended resolutions. If more than one file is to be used, the NAME, CLASS, DISK and SEQ of the subsequent image files will be the same as the first file except that the LAST 3 or 4 characters of the CLASS will be an increasing sequence above that in IN2CLASS. Thus, if INCLASS='ICL005', classes 'ICL005' through 'ICLnnn' or 'ICnnnn', where nnn = 5 + NMAPS - 1 will be used. Old names (in which the 4'th character is not a number) are also supported: the last two characters are '01' through 'E7' for fields 2 through 512. In old names, the highest field number allowed is 512; in new names it is 4096. CHANNEL....Frequency channel, 0 => all (use 0 for continuum) BIF........First IF to process. 0=>1 EIF........Highest IF to process 0=> do BIF to highest. Note: not all data sets will have IFs. IN2NAME....Model map name (name). Standard defaults. IN2CLASS...Model map name (class). Standard defaults. IN2SEQ.....Model map name (seq. #). 0 => highest. IN2DISK....Disk drive # of model map. 0 => any. INVER......CC file ver. number. 0 => highest. OUTNAME....Output UV file name (name). Standard defaults. OUTCLASS...Output UV file name (class). Standard defaults. OUTSEQ.....Output UV file name (seq. #). 0 => highest unique. OUTDISK....Disk drive # of output UV file. 0 => highest with space BCOMP......The first clean component to process. One value is specified for each field used. NCOMP......Number of Clean components to use for the model, one value per field. If all values are zero, then all components in all fields are used. If any value is not zero, then abs(NCOMP(i)) (or fewer depending on FLUX and negativity) components are used for field i, even if NCOMP(i) is zero. If any of the NCOMP is less than 0, then components are only used in each field i up to abs(NCOMP(i)), FLUX, or the first negative whichever comes first. If abs(NCOMP(i)) is greater than the number of components in field i, the actual number is used. For example NCOMP = -1,0 says to use one component from field one unless it is negative or < FLUX and no components from any other field. This would usually not be desirable. NCOMP = -1000000 says to use all components from each field up to the first negative in that field. NCOMP = -200 100 23 0 300 5 says to use no more than 200 components from field 1, 100 from field 2, 23 from field 3, 300 from field 5, 5 from field 6 and none from any other field. Fewer are used if a negative is encountered or the components go below FLUX. FLUX.......Only components > FLUX in absolute value are used in the model. CPARM......Task enrichment parameters: (1) If CPARM(1) is > 0 then a correction is applied for the effects of bandwidth smearing. The value of CPARM(1) gives the maximum correction in percent. (2) If CPARM(2) > 0 then CPARM(2) is a factor to be multiplied times the nominal (header) value of the bandwidth before making the bandwidth smearing correction. (3) If CPARM(3) > 0 then CPARM(3) is a factor to correct the reference frequency. This will correct both the reference frequency and the values of, u, v and w in the output dataset. FACTOR.....This value will be multiplied times the CLEAN component flux densities before addition. The default 0->1.0, so the clean component model will be added from the UV data. FACTOR=-1 will subtract the clean component model from the uv data. SMODEL.....A single component model to be used instead of a CLEAN components model; if abs (SMODEL) > 0 then use of this model is requested. SMODEL(1) = flux density (Jy) SMODEL(2) = X offset in sky (arcsec) SMODEL(3) = Y offset in sky (arcsec) SMODEL(4) = Model type (uses point only) BADDISK....The disk numbers to avoid for scratch files. ----------------------------------------------------------------