; VLBABPSS ;--------------------------------------------------------------- ;! computes spectral bandpass correction table ;# TASK CALIBRATION AP SPECTRAL ;----------------------------------------------------------------------- ;; Copyright (C) 2015 ;; 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 ;----------------------------------------------------------------------- VLBABPSS LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC VLBABPSS Procedure to create BP table and correct auto-correlations 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 # Data Selection CALSOUR Bandpass calibrator sources. CALCODE Calibrator code ' '=>all TIMERANG Time range to select ANTENNAS Antennas to select CLEAN map (optional) IN2NAME Cleaned map name (name) IN2CLASS Cleaned map name (class) IN2SEQ 0.0 9999.0 Cleaned map name (seq. #) IN2DISK 0.0 9.0 Cleaned map disk unit # INVERS -1.0 46655.0 CC file version #. NCOMP # comps to use for model. 1 value per field FLUX Lowest CC component used. NMAPS 0.0 4096.0 No. Clean map files CMODEL Model type: 'COMP','IMAG' 'SUBI' (see HELP re images) SMODEL Source model, 1=flux,2=x,3=y See HELP SMODEL for details. Control options REFANT Reference antenna VLBABPSS is defined in the VLBAUTIL run file. ---------------------------------------------------------------- VLBABPSS Type: Procedure Use: VLBABPSS run BPASS to VLBA data. Then it runs ACSCL with all the previous calibration applied (sampler corrections, bandpass corrections) and produces additional corrections based on the autocorrelations in order to return them to unity. This is a new prodecure based on the recommendations laid out in VLBA Scientific Memo #37 (Craig Walker). 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. CALSOUR....List of sources for which bandpass response functions are to be determined. All ' ' = all sources; a "-" before a source name means all except ANY source named. If the data file is a single-source file no source name need be specified. If both IN2NAME and IN2CLASS are specified, but multiple sources are selected, BPASS will quit. CALCODE....Calibrators may be selected on the basis of the calibrator code: ' ' => any calibrator code selected '* ' => any non blank code (cal. only) '-CAL' => blank codes only (no calibrators) anything else = calibrator code to select. NB: The CALCODE test is applied in addition to the other tests, i.e. CALSOUR and QUAL, in the selection of sources for which to determine solutions. TIMERANG...Time range of the data to be selected. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to reference date. ANTENNAS...A list of the antennas for which bandpasses are to be determined. If any number is negative then all antennas listed are NOT to be used and all others are. The following specify a CLEAN model to be used if a single source was specified in CALSOUR IN2NAME....Cleaned map name (name). ' ' => no Clean model Note: a CLEAN image for only a single source may be given although the uv data may be in a multi-source file. If the source table contains a flux, then that flux will be used to scale the components model to obtain the stated total flux. This is needed since initial Cleans may not obtain the full flux even though they represent all the essentials of the source structure. IN2CLASS...Cleaned map name (class). ' ' => no Clean model If a Clean model is specified, then only one source may be selected (multi-source files) and no SMODEL may be specified (single-source files). IN2SEQ.....Cleaned map name (seq. #). 0 -> highest. IN2DISK....Disk drive # of cleaned map. 0 => any. INVERS.....CC file version #. 0=> highest numbered version 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. 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. 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: when using a model derived from data with different uv sampling it is best to use 'DFT' 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. 'SUBI' means that the model consists of a sub-image of the original IMAGR output. If CMODEL is ' ' Clean components will be used if present and the image if not. SUBI should work for sub-images made with DO3DIM true and sib-images of the central facet made with DO3DIM false, but probably will not work well for shifted facets with DO3DIM false. Use BLANK rather than SUBIM in such cases. CALIB will set a scaling factor to correct image units from JY/BEAM to JY/PIXEL for image models. If the source table contains a flux, then that flux will be used to scale the components model to obtain the stated total flux. This is needed since initial Cleans may not obtain the full flux even though they represent all the essentials of the source structure. SMODEL.....For single-source files only: a single component model to be used instead of a CLEAN components model; if SMODEL(1) > 0 then use of this model is requested. Note that IN2NAME or IN2CLASS must be blank if SMODEL(1) > 0 and both must be specified if SMODEL(1) <= 0 for single-source files. 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) REFANT.....The antenna to use as a reference in the least-squares solution. ---------------------------------------------------------------- VLBABPSS: Procedure to determine antenna bandpass functions from calibrator data and do final scaling with the auto- correlations Documentor: Amy Mioduszewski Related Programs: BPASS This procedure is defined in VLBAUTIL. VLBABPSS determines the bandpass calibration using BPASS. VLBABPSS should be used along with VLBACCIR and VLBAAMP instead of VLBACALA. This redesign of the amplitude calibration path is based on VLBA Scientific Memo #37 (Craig Walker). The new recommended steps for amplitude calibration are: 1) Do preliminary calibration steps that are necessary (e.g., VLBAFIX, VLBAEOPS, VLBATECR...). 2) VLBACCOR -- digital sampling corrections 3) VLBAMPCL (or VLBAPCOR) -- remove instrumental delay 4) VLBABPSS -- do bandpass 5) VLBAAMP -- correct auto-correlations and a priori amplitude calibration 6) Continue with calibration.