; MAPBM ;--------------------------------------------------------------- ;! Map VLA beam polarization ;# TASK CALIBRATION POLARIZATION UV Image VLA OOP ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1997, 2000, 2002-2003, 2006-2007, 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 ;; 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 ;----------------------------------------------------------------------- MAPBM LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC MAPBM: Map VLA beam polarization INNAME Input UV data (name) INCLASS Input UV data (class) INSEQ Input UV data (seq. #) INDISK Input UV data disk drive # SOURCES Source (pointings) list QUAL Source qualifier TIMERANG Time range to process. BIF 0.0 100.0 Lowest IF number 0=>all EIF 0.0 100.0 Highest IF number 0=>all PMODEL Source polarization DOCALIB -1.0 101.0 > 0 calibrate data & weights > 99 do NOT calibrate weights GAINUSE CL table to apply DOPOL -1.0 10.0 If >0.5 correct polarization. PDVER PD table to apply (DOPOL>0) BLVER BL table to apply. FLAGVER Flag table version DOBAND -1.0 10.0 If >0 apply bandpass cal. Method used depends on value of DOBAND (see HELP file). BPVER Bandpass table version SMOOTH Smoothing function. See HELP SMOOTH for details. OUTNAME Output image name (name) OUTDISK Output image disk drive # Note: OUTCLASS='ANT_#' 'RMS_#' for rms maps where # is antenna number. OUTSEQ -1.0 32000.0 Output seq. no. IMSIZE 1. 4096. Image size (X,Y) in pixels CELLSIZE 1.E-12 (X,Y) size of grid in asec APARM Task enrichment parms (1) Avg. time in sec. (2) Blank time at the begin. of the avg. time in sec. (3) 0 => no rms maps 1 => yes rms maps no scaling for the rms maps (4) 0 => Yes dividing of a polarization map by its maximum 1 => No dividing of a polarization map by its maximum (5) 0 => create separate maps for each of selected antennas 1 => combine data of all selected antennas and create one map ANTENNAS Selected antennas from the list of measured antennas 0 => all If any number is negative then all antennas listed are NOT selected and all others are. BASELINE The reference antenna list Must be given!!! BADDISK Disk drive #'s to avoid ---------------------------------------------------------------- MAPBM Type: Task Use: Image VLA quasi "holography" mode data to make total intensity gain images and images of the fractional Q, U and V polarizations. The uv data are expected to be rasters in azimuth and elevation. Prior calibration and editing may be applied and then the data is then averaged over baseline. The resultant images are the qubes of primary beam (and the rms of each of these) for each of the selected antennas with the stokes I, Q, U and V as the third axis. For Stokes I, the image is the average observed I divided by PMODEL(1). For the other values of Stokes the image values are the real part of the ratio of the complex Stokes' value to I (complex also) after correction for source polarization. Note: QUACK is needed to eliminate the first couple of integrations of a raster while the on-line system (VLA 9/93) sorts out where it needs to be. Note: QUACK may not be enough; exceedingly painful, careful editing of the data will be needed to insure that all the spurious points are removed. Adverbs: INNAME.....Input UV data file (name). Standard defaults. MUST be a multi source file. INCLASS....Input UV data file (class). Standard defaults. INSEQ......Input UV data file (seq. #). 0 => highest. INDISK.....Input UV data file disk drive #. 0 => any. SOURCES....List of sources (pointings) to be processed. All blank means any. QUAL.......Source qualifier for rasters. TIMERANG...Time range of the data to be processed. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to ref. date. BIF........First IF to image. 0=>all. EIF........Highest IF to image. 0=>all higher than BIF PMODEL.....The Stokes parameters for the source. PMODEL(1) = I flux density (Jy) PMODEL(2) = Q flux density (Jy) PMODEL(3) = U flux density (Jy) PMODEL(4) = V flux density (Jy) DOCALIB....If true (>0), calibrate the data using information in the specified Cal (CL) table for multi-source or SN table for single-source data. Also calibrate the weights unless DOCALIB > 99 (use this for old non-physical weights). GAINUSE....CL table version number to apply. 0=> highest. DOPOL......If > 0.5 then correct data for instrumental polarization as represented in the AN or PD table. This correction is only useful if PCAL has been run or feed polarization parameters have been otherwise obtained. See HELP DOPOL for available correction modes: 1 is normal, 2 and 3 are for VLBI. 1-3 use a PD table if available; 6, 7, 8 are the same but use the AN (continuum solution) even if a PD table is present. PDVER......PD table to apply if PCAL was run with SPECTRAL true and 0 < DOPOL < 6. <= 0 => highest. BLVER......Version number of the baseline based calibration (BL) table to appply. <0 => apply no BL table, 0 => highest. FLAGVER....Specifies the version of the flagging table to be applied. 0 => highest numbered table. <0 => no flagging to be applied. DOBAND.....If true (>0) then correct the data for the shape of the antenna bandpasses using the BP table specified by BPVER. The correction has five modes: (a) if DOBAND=1 all entries for an antenna in the table are averaged together before correcting the data. (b) if DOBAND=2 the entry nearest in time (including solution weights) is used to correct the data. (c) if DOBAND=3 the table entries are interpolated in time (using solution weights) and the data are then corrected. (d) if DOBAND=4 the entry nearest in time (ignoring solution weights) is used to correct the data. (e) if DOBAND=5 the table entries are interpolated in time (ignoring solution weights) and the data are then corrected. BPVER......Specifies the version of the BP table to be applied. <0 => no bandpass correction done. SMOOTH.....Specifies the type of spectral smoothing to be applied to a uv database . The default is not to apply any smoothing. The elements of SMOOTH are as follows: SMOOTH(1) = type of smoothing to apply: 0 => no smoothing To smooth before applying bandpass calibration 1 => Hanning, 2 => Gaussian, 3 => Boxcar, 4 => Sinc To smooth after applying bandpass calibration 5 => Hanning, 6 => Gaussian, 7 => Boxcar, 8 => Sinc SMOOTH(2) = the "diameter" of the function, i.e. width between first nulls of Hanning triangle and sinc function, FWHM of Gaussian, width of Boxcar. Defaults (if < 0.1) are 4, 2, 2 and 3 channels for SMOOTH(1) = 1 - 4 and 5 - 8, resp. SMOOTH(3) = the diameter over which the convolving function has value - in channels. Defaults: 1,3,1,4 times SMOOTH(2) used when input SMOOTH(3) < net SMOOTH(2). OUTNAME....Output image name (name). Standard defaults. OUTDISK....The disk drive # of output images. 0 => highest with space. Note: OUTCLASS='ANT_#' ('RMS_#' for rms maps) where # is the antenna number. In the case when all antenna data averaged (APARM(5) = 1) OUTCLASS='ANT_*' OUTSEQ.....Output sequence number. 0 => highest unique. IMSIZE.....(X,Y) image size in pixels. Should be odd. CELLSIZE...(X,Y) pixel separation in asec. It should be close to the actual separation at the pointing at the holography measurements. APARM......Task enrichment parameters. (1) Averaging time in seconds; normally interval of each pointing. (2) Time in seconds to ignore at the beginning of each pointing; this allows for antenna move. (3) 0 => no rms maps 1 => yes rms maps no scaling (dividing by the map maxima) for the rms maps (4) 0 => Yes dividing of a polarization map by its maximum 1 => No dividing of a polarization map by its maximum (5) 0 => create separate maps for each selected antennas 1 => combine data of all selected antennas and create one map ANTENNAS...A list of the antennas to be selected. 0 => all. If any number is negative then all antennas listed are NOT selected and all others are. ANTENNAS list is the list of measured antennas. BASELINE...List of the reference antennas. Must be given!!! BADDISK....Disk drive #'s to avoid for scratch files ---------------------------------------------------------------- You can create the average maps averaging all selected antennas and all selected reference antennas, or You can create maps for each selected antenna separately. OUTCLASS of the output map is 'ANT_#'. For 'rms' maps the OUTCLASS of the output map is 'RMS_#'. where # is the antenna number. In the case when all antenna data averaged (APARM(5) = 1) OUTCLASS='ANT_*' Each output map is the cube with the third axis dimension is 4 (one plate for Stokes parameter). So KNTR can plot all polarization at one page. The four maps can be normalized to 1(one) (APARM(4)) dividing by the maximum value at each plate. No normalization for the 'rms' maps. So the values of the maps have to be multiplied by the scale factors. The value of the scale factors can be found as keywords using aips verb 'imh' The scaling all stokes maps to 1, simplifies selection of the levels in KNTR.