; SNSMO ;--------------------------------------------------------------- ;! smooths and filters a calibration SN table ;# Task Calibration ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1997, 2001, 2003, 2005, 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 ;----------------------------------------------------------------------- SNSMO LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC SNSMO Task which smooths and filters Solution(SN) tables. 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 # SOURCES Source list ' '=>all. DOBTWEEN -1.0 1.0 > 0 -> smooth all sources together; else separate them SELBAND Bandwidth to select (kHz) SELFREQ Frequency to select (MHz) FREQID Freq. ID to select, 0=>all BIF 0.0 100.0 Lowest IF number 0=>all EIF 0.0 100.0 Highest IF number 0=>all TIMERANG Time range to use. ANTENNAS Antennas to correct. SUBARRAY 0.0 9999.0 Subarray; 0 => all. SAMPTYPE Smoothing function BPARM Smoothing parameters CUTOFF 0.0 Cutoff for functional forms DOBLANK Blanked value interpolation SMOTYPE Data to smooth CPARM Range of allowed delays and rates. NORMALIZ -1.0 4.0 > 0 => apply a global normaliztion - see HELP INVERS Input SN table; 0=>highest OUTVERS Output SN table; 0=>new REFANT Reference antenna 0=>pick. BADDISK 0.0 9999.0 Disks to avoid for scratch ---------------------------------------------------------------- SNSMO Task: This task references and smooths an SN table. First rates and delays can be clipped to a specified range of values. Next phase like values (phase, delays and rate) are rereferenced if necessary to a single antenna. This rereferencing is done in a manner which should preserve the coherence of the two orthoginal polarization systems. Following the referencing the solutions are smoothed in a manner to preserve coherence, rates may be averaged before smoothing and the average phase difference between the orthogonal polarizations before smoothing is enforced on the solutions after smoothing. Blanked solutions will be interpolated or not under control of DOBLANK. WARNING: THIS TASK WAS CHANGED 27 MARCH, 2003. The smoothing no longer propagates good solutions indefinitely. Instead the support size is strictly enforced. Additional smoothing options are now available. DOBLANK is now changed: if it is < 0, failed solutions are not fixed, if it is >= 0 they are fixed. If it is <= 0, good solutions are smoothed, if it is > 0 good solutions are not altered. 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. SOURCES....list of sources to process: '*' = all; a "-" before a source name means all except ANY source named. DOBTWEEN...> 0 => smooth all SN values regardless of source. <= 0 => smooth only SN values from the same source. Well-separated calibrators may have different phases just because of different atmosphere, so one would not want to smooth them together. This can be achieved via doing one source at a time, but DOBTWEEN allows one to do all sources at once - at least if the choice is a simple one. FREQID.....Frequency identifier to select (you may determine which is applicable from the OPTYPE='SCAN' listing produced by LISTR). BIF........First IF to process. 0=>all. EIF........Highest IF to process. 0=>all higher than BIF TIMERANG...Time range of the data to be used. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to reference date. ANTENNAS...A list of the antennas to be modified. If any number is negative then all antennas listed are NOT to be modified. All 0 => use all. SUBARRAY...The subarray to modify. 0 -> all. SAMPTYPE...The type of smoothing. 'BOX ' = boxcar smoothing (default) 'MWF ' = Median window filter 'GAUS' = Gaussian 'EXP ' = Exponential 'LINE' = Linear (1 - abs(t-t0)/sigma) '2PT ' = Two-point '2PTH' = Two-point + "Hanning" BPARM......Parameters for smoothing function. Function support full-width width in hours. (1) => support time for amplitudes, (2) => support time for phase, (3) => support time for rates (4) => support time for singleband delay (5) => support time for multiband delay Added parameter (FWHM) for GAUS, EXP, LINE (6) => smoothing FWHM time for amplitudes, (7) => smoothing FWHM time for phase, (8) => smoothing FWHM time for rates (9) => smoothing FWHM time for singleband delay (10) => smoothing FWHM time for multiband delay In all cases, the substitution for blanked and good solutions is governed by DOBLANK (see below) CUTOFF.....Cutoff for GAUS, EXP, LINE. The sum of the weighting function in the support region must exceed CUTOFF for the smoothed value to be regarded as valid. Be careful, a value of 1.5 means that the sample itself must be good and the sum over other good samples in the support range must exceed 0.5. < 1.e-6 => 1.e-6. DOBLANK....Blanked value interpolation: > 0: replace previously blanked values with smoothed values, leave previously good values unchanged. = 0: replace previously blanked and previously good values with smoothed values. < 0: replace previously good values with smoothed values, leave previously blanked values blanked. Note that DOBLANK >= 0 requires a SMOTYPE that smooths both phase and amplitude, namely BOTH, FULL, VLBI, or VLMB. SMOTYPE....Specified the data to be smoothed. ' '=>'AMPL' 'AMPL' = amplitude smoothing only, 'PHAS' = phase smoothing only, 'BOTH' = amplitude and phase, 'DELA' = delay smoothing only, 'VLBI' = Coherent phase, rate and delay smoothing. Phases smoothed in each IF separately. 'VLRI' = Coherent phase, rate and delay smoothing. Phases smoothed in each IF separately, but rates are averaged over IF as well as polarization. 'VLMB' = Like VLBI and VLRI but phases are averaged over IF before smoothing. The average phase is the phase of vector average of the complex amplitudes. The average amplitude is the scalar average of the amplitudes. 'FULL' = same as VLBI CPARM......Data can be clipped by comparison with a median window filter. The width of the Median window is specified in CPARM(1-5). The maximum allowed deviation is given in CPARM(6-10). 0 => all values are OK. (1) => smoothing time for amplitudes, (2) => smoothing time for phase (3) => smoothing time for rates (4) => smoothing time for singleband delay (5) => smoothing time for multiband delay (6) => Max. deviation for amplitudes, (7) => Max. deviation for phase, (deg) (8) => Max. deviation for rates (mHz) (9) => Max. deviation for singleband delay (nsec) (10) => Max. deviation for multiband delay (nsec) The clipping on rates is based on the MWF of the average rate over IF compared to the individual rates. The amplitude, phase, and SB delay are done one IF at a time. NORMALIZ...Controls whether a global gain normalization is applied to the table. If there was one previously and NORMALIZ=0 or if NORMALIZ > 0, a global normalization is applied. Otherwise, the global normalization parameter is left unchanged. INVERS.....input version number of the SN table to smooth. 0 => Highest. OUTVERS....output version of SN table to write. 0 => create new table. REFANT.....Reference antenna to use. All phase-like values in the SN table will be referenced to this antenna. 0=> use the one used in the most solutions. BADDISK....A list of disks on which scratch files are not to be placed. This will not affect the output file. ---------------------------------------------------------------- SNSMO: Smooths solution (SN) tables. Documentor: W. D. Cotton Related Programs: CALIB, FRING, CLCAL, SNCOR This task re-references an SN table to a common antenna (REFANT) and then allows smoothing of a variety of data types in an solution (SN) table. This re-referencing and smoothing is done in a way that will maintain phase coherence between the right and left (or orthogonal linear) systems. Phase smoothing is done after removing the integral of the fringe rate which is then replaced after smoothing. This allows the possibility of sensible phase smoothing with non-zero fringe rates. It is recommended that this task not overwrite the original table to protect aginst errors. The SN table differs from the standard SN table by the inclusion of multiband delays for the two polarizations and the IF phases are at the IF frequency. SMOTYPE = 'VLBI' This option causes the residual rates for R and L polarizations to be averaged to maintain R-L coherence. The rates in each IF are processed independently. Values in the "Multiband" delay columns will be processed but the phases in each IF are processed independently. SMOTYPE = 'VLRI' This option causes all residual rates for a given time and antenna to be averaged over both IF and polarization and the phases for the two polarizations of a given IF are forced to maintain R-L coherence. Values in the "Multiband" delay columns will be processed but the phases in each IF are processed independently. SMOTYPE = 'VLMB' This option is designed for data which has been fringe fitted for a multiband delay. In this case the phase in each IF should be estimates of the same (or identical) values. Thus the phases are averaged in IF before smoothing. The average phase is the phase of vector average of the complex amplitudes. The amplitude is the scalar average of the amplitudes. SAMPTYPE '2PT ' - interpolates in time between the two nearest neighbors of a flagged sample within the support time range This mode is really only for DOBLANK > 0. '2PTH' - interpolates in time between the two nearest neighbors of a sample within the support time range, then averages the sample (if good) with the interpolated value. When there is only one good neighbor, the sample itself counts double if it is good.