; OOSUB ;--------------------------------------------------------------- ;! Subtracts/divides a model from/into a uv data base ;# TASK UV IMAGING MODELING CALIBRATION OOP ;----------------------------------------------------------------------- ;; Copyright (C) 2007-2010 ;; 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 ;; 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 ;----------------------------------------------------------------------- OOSUB LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC OOSUB Task to subtract CLEAN components from a uv data base. (or, to divide observed visi- bility by model visibility) 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. CMETHOD Modeling method: 'DFT','GRID',' ' CMODEL Model type: 'COMP','IMAG' (see HELP re images) FACTOR Factor times CLEAN fluxes. 0->1.0 Subtract -1.0 Add OPCODE 'DIV ' => divide visibility observation by model vis. 'MODL' => replace visibility with model visibility anything else => subtract SMODEL Source model, 1=flux,2=x,3=y See HELP SMODEL for models. BPARM Task enrichment parameters (1) Antenna diameter (m) 0 -> no correction (2) Omit CC options (3) spectral index radius 0 -> no correction FQTOL Frequency tolerance in kHz (primary beam & spec index) IN3NAME Spectral index image name IN3CLASS Spectral index image class IN3SEQ Spectral index image sequence number IN3DISK Spectral index image disk IN4NAME Spectral curvature name IN4CLASS Spectral curvature class IN4SEQ Spectral curvature sequence number IN4DISK Spectral curvature disk BADDISK Disks to avoid for scratch ---------------------------------------------------------------- OOSUB Task: Subtracts/divides a model from/into a uv data base. The model may be a specific model, a set of CLEAN components files, or a set of images. "CLEAN" models may be points, Gaussians or uniform, optically thin spheres. The task will also subtract the model and then re-read the result replacing the difference with the model value. Model images made with both values of IMAGR's DO3DIMAG option are handled correctly, as are multi-scale images. Set NMAPS = NFIELD * NGAUSS. OOSUB works only on single-source files. OOSUB differs from UVSUB in that it offers the frequency-dependent primary beam and spectral index options found in IMAGR. 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) If > 0, then subtract/divide only this channel but copy all channels with the others unchanged. NOTE WELL: EIF will be set to BIF if CHANNEL >= 1. 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. See note under CHANNEL directly above too. If the IF axis precedes the FREQ axis in the header, then all IFs must be done if all spectral channels are to be done. 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. CMETHOD....This determines the method used to compute the model visibility values. 'DFT' uses the direct Fourier transform, this method is the most accurate. 'GRID' does a gridded-FFT interpolation model computation. ' ' allows the program to use the fastest method. NOTE: data in any sort order may be used by the 'DFT' method but only 'XY' sorted data may be used by the 'GRID' method. NOTE: CMETHOD='GRID' does not work correctly for RL and LR data; DO NOT USE CMETHOD='GRID' for RL, LR! CMODEL.....This indicates the type of input model; 'COMP' means that the input model consists of Clean components, 'IMAG' indicates that the input model consists of images. If CMODEL is ' ' Clean components will be used if present and the image if not. Note that Clean images do not make good models. The Clean components have been convolved with the Gaussian Clean beam making their Fourier transform be rather tapered compared to the original uv data. FACTOR.....This value will be multiplied times the CLEAN component flux densities before subtraction. The default 0->1.0, so the clean component model will be subtracted from the UV data. FACTOR=-1 will add the clean component model to the UV data. FACTOR will be adjusted by OOSUB for image models that are in JY/BEAM. FACTOR is used with all OPCODEs. OPCODE.....OPCODE='DIV ' => divide observed visibility by model visibility. OPCODE='MODL' => replace the visibility with the model visibility. Any other setting of OPCODE causes the task to subtract the model visibility from the observed visibility (the normal mode of operation). 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: 0 => point model 1 => elliptical Gaussian and SMODEL(5) = major axis size (arcsec) SMODEL(6) = minor axis size (arcsec) SMODEL(7) = P. A. of major axis (degrees) 2 => uniform sphere and SMODEL(5) = radius (arcsec) BPARM......Correction control parameters (SEE EXPLAIN IMAGR): (1) If > 0 then make frequency dependent primary beam corrections assuming an antenna diameter of IMAGRPRM(1) meters. Note that VLA and ATCA arrays (TELESCOPE header parameter) use the default primary beam parameters defined elsewhere in AIPS, while other antennas actually use IMAGRPRM(1) as the diameter of a "standard" telescope. See FQTOL below also. (2) If BPARM(1) > 0, you may omit selected CCs from the operation based on position: BPARM(2) <= 0 : Include all CCs = 1 : Omit CCs within the main beam at all frequencies = 2 : Omit CCs within the main beam at some frequncies = 3 : Omit Ccs outside the main beam at some frequencies = 4 : Omit CCs outside the main beam at all frequencies (3) 1 => use a spectral-index image represented in IN3NAME, IN3CLASS, IN3SEQ, IN3DISK below to correct the Clean component model for each channel. IN4NAME et al will also be used as a curvature image iff IN3NAME are specified. bparm(3)-0.5 is used as a radius in pixels over which the spectral index image is averaged. When it is small (0 < BPARM(3) <~ 1), the spectral index is interpolated rather than averaged. See FQTOL below as well. When doing spectral index, the primary beam correction (BPARM(1)) costs very little extra. This parameter is IMAGRPRM(17) in IMAGR. FQTOL......Frequency tolerance in kHz. Spectral channels with FQTOL are handled together (use the same average CC model) when applying the primary beam and spectral index corrections. Default is to do each channel separately which can take a long time. IN3NAME....Image name of spectral index image; no default. IN3CLASS...Image class of spectral index image; no default. IN3SEQ.....Image sequence of spectral index image; 0 -> highest. IN3DISK....Disk of spectral image image; 0 -> any. IN4NAME....Image name of spectral index curvature image; no default. Curvature images should be base 10 rather than base e - they differ by a factor of 2.3. Also the reference frequency is 1.0 GHz. These are changes done 2010-07-13. IN4CLASS...Image class of spectral index curvature image; no default. IN4SEQ.....Image sequence of spectral index curvature image; 0 -> highest. IN4DISK....Disk of spectral curvature image image; 0 -> any. BADDISK....The disk numbers to avoid for scratch files. ----------------------------------------------------------------