; RFI ;--------------------------------------------------------------- ;! Look for RFI in uv data ;# TASK CALIBRATION OOP EDITING ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1996, 1999-2000, 2003, 2006-2007 ;; 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 ;----------------------------------------------------------------------- RFI LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC RFI Look for RFI in a uv data set. INNAME Input UV data INCLASS Input UV data (class) INSEQ Input UV data (seq. #) INDISK Input UV data disk drive # SOURCES Source (pointings) list QUAL -10.0 Source qualifier -1=>all CALCODE Calibrator code ' '=>all TIMERANG Time range to process. SELBAND Bandwidth to select (kHz) SELFREQ Frequency to select (MHz) FREQID Freq. ID to select. BIF 0.0 100.0 Lowest IF number 0=>all EIF 0.0 100.0 Highest IF number 0=>all BCHAN 0.0 2048.0 Lowest channel number 0=>all ECHAN 0.0 2048.0 Highest channel number 0=>all SUBARRAY 0.0 1000.0 Subarray, 0=>all DOCALIB -1.0 101.0 > 0 calibrate data & weights > 99 do NOT calibrate weights GAINUSE CL/SN table to apply DOPOL -1.0 10.0 If >0 correct polarization. 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. UVRANGE 0. Min & max baseline (klambda) SOLINT Time interval (sec) BPARM (1) Fraction allowable bad baselines. (2) rms cutoff (Jy) (3) Amp. factor for cutoff DOCRT -1.0 132.0 > 0 -> use the terminal, else use the line printer > 72 => terminal width OUTPRINT Printer disk file to save BADDISK -1.0 1000.0 Disks to avoid for scratch. ---------------------------------------------------------------- RFI Type: Task Use: Detect interference using the rms amplitude in each correlator. Currently works for up to 8 correlators. Either single or multisource data files can be processed. This task computes the rms sine and cosine fluctuations in each baseline/correlator and compares them with the value of BPARM(2) plus the average source amplitude times BPARM(3), in quadrature. If the fraction of bad baselines in any correlator exceeds BPARM(1) a message is generated. When a message is generated, the source name and time range is given followed by a list of logical flags, one per correlator in the order that they appear in the data. T indicates that the corresponding correlator exceeded the maximum number of flagged baselines; F indicates otherwise. If the output format is sufficiently wide, the correlator number and the average rms value of offending baselines for the worst baseline/correlation is given. Adverbs: INNAME.....Input UV data 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. '*' or blank = all; a "-" before a source name means all except ANY source named. QUAL.......Only sources with a source qualifier number in the SU table matching QUAL will be used if QUAL is not -1. CALCODE...."sources" may be selected on the basis of the calibrator code given in the SU table. ' ' => any calibrator code selected '* ' => any non blank code (cal. only) '-CAL' => blank codes only (no calibrators) NB: The CALCODE test is applied in addition to the other tests, i.e. SOURCES and TIMERANG, in the selection of sources to process. CALCODE affects only the selection of calibrators. 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. SELBAND....Bandwidth of data to be selected. If more than one IF is present SELBAND is the width of the first IF required. Units = kHz. For data which contain multiple bandwidths/frequencies the task will insist that some form of selection be made by frequency or bandwidth. SELFREQ....Frequency of data to be selected. If more than one IF is present SELFREQ is the frequency of the first IF required. Units = MHz. FREQID.....Frequency identifier to select (you may determine which is applicable from the OPTYPE='SCAN' listing produced by LISTR). If either SELBAND or SELFREQ are set, their values overide that of FREQID. However, setting SELBAND and SELFREQ may result in an ambiguity. In that case, the task will request that you use FREQID. 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). BIF........First IF to select. 0=>all. EIF........Highest IF to select. 0=>all higher than BIF BCHAN......First channel to select. 0=>all. ECHAN......Highest channel to select. Use BIF, EIF, BCHAN, ECHAN to limit the total number of correlators to 8 or fewer. SUBARRAY...Subarray number to consider. 0=>all. GAINUSE....CL table version number to apply. 0=> highest. DOPOL......If > 0 then correct data for instrumental polarization as represented in the AN table. Only one subarray may be done at a time. 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. 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 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). UVRANGE....(Minimum,Maximum) baseline (kilo-lambda) to process. SOLINT.....The interval over which the rms is determined. 0 => 60 seconds. BPARM......Task enrichment parameters: BPARM(1)...The fraction of baselines which can exceed the rms limit before the integration is listed as bad. 0 => 0.25 BPARM(2)...The maximum allowable sine/cosine rms per baseline/correlator. No default. BPARM(3)...Source amplitude coefficient for determining bad baselines. The maximum allowed rms is given by: sqrt (BPARM(2)**2 + (avg_amp*BPARM(3))**2) Note: the value of BPARM(3) is a compromise between false detection of interference on strong sources and missing interference on weak sources as the interference may mimic a strong source. DOCRT......False (<= 0) use the line printer if OUTPRINT = ' ' else write named OUTPRINT file only. True (> 0) use the terminal interactively. The task will use the actual terminal width as a display limit unless 72 < DOCRT < width. In that case, the display limit will be DOCRT characters. OUTPRINT...Disk file name in which to save the line printer output. ' ' => use scratch and print immediately for interactive jobs - batch jobs use OUTPRINT = 'PRTFIL:BATCHjjj.nnn' (jjj= job #, nnn = user #). When OUTPRINT is not blank, multiple outputs are concatenated, and the file is not actually printed. BADDISK...This array contains the numbers of disks on which it is desired that scratch files not be located. BADDISK has no effect input data. ---------------------------------------------------------------- RFI: Task to find periods of interference Documentor: W. D. Cotton NRAO Related Programs: TVFLG, UVFLG The purpose of this task to to find periods of interference based on high values of the RMS of either the sine or cosine parts of the visibilities in a given interval. Each baseline and correlator is analysed separately and if the fraction of baselines on a given correlator (e.g. IF 2, channel 1, RR) exceeds a specified level this interval is listed in the output. Correlators Correlators are specified by a correlator number. This number is the number in a sequence with polarization (RR, LL, RL, LR) varying the fastest, then frequency channel, then IF. For VLA continuum data correlator 6 is IF 2 LL.