; AFARS ;-------------------------------------------------------------------- ;! Is used after FARS to determine Position and Value of the maximum ;# TASK ANALYSIS POLARIZATION ;-------------------------------------------------------------------- ;; Copyright (C) 2011-2012 ;; 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 ;----------------------------------------------------------------------- AFARS LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC AFARS: Find RM of maximum amplitude and the Amp/Phase there INNAME First image (real/ampl) name INCLASS First image class INSEQ 0.0 9999.0 First image seq. # INDISK 0.0 9.0 First image disk drive # IN2NAME 2nd image (imag/phase) name IN2CLASS 2nd image class IN2SEQ 0.0 9999.0 2nd image seq. # IN2DISK 0.0 9.0 2nd image disk drive # OUTNAME Output images name RM OUTSEQ -1.0 9999.0 Output images seq. # OUTDISK 0.0 9.0 Output images disk # DOALIGN -2.0 1.0 Should images be coincident? (See HELP.) BLC 0.0 4096.0 Bottom left corner TRC 0.0 4096.0 Top right corner OPCODE 'CMPL' => 2nd and 3rd outputs real and imaginary at peak, else amplitude and phase BPARM (1) If peak < BPARM(1), blank output RM and phase (2) Value for blanked RMs -1111 => magic blank (3) Value for blanked phases -1111 => magic blanks (5) method of finding peak DOHIST -3.0 1.0 -2 => copy 1st HI only -3 => copy no HI files ---------------------------------------------------------------- AFARS Type: Task The task may be used to find the position and value of maximum of the spectrum given in the input cubes. The cubes should be the output cubes of the task FARS (CLEAN or UNCLEAN) with reals in the first cube and imaginaries in the second cube OR with amplitudes in the first cube and phases in the second cube. These images are the output of FARS (not the transposed output from the procedure DOFARS) and so have the RM spectrum on the first axis and RA/Dec on the second and third axes. The first output image: Position of maximum in radians/m^2. The second and third output images: Real and imaginary at the position of maximum in Jy/beam if OPCODE='CMPL'; otherwise the maximum amplitude in Jy/beam and the phase at the position of the maximum in degrees. Adverbs: USERID......The ID of the owner of the images. 0 => current user, 32000 => any user. INNAME......First image name. (amplitude) INCLASS.....First image class. Standard defaults. INSEQ.......First image seq. #. 0 => highest. INDISK......Disk drive # for the first image. 0 => any. IN2NAME.....Second image name (phase) IN2CLASS....Second image class. Standard defaults. IN2SEQ......Second image seq. #. 0 => highest. IN2DISK.....Disk drive # for the second image. 0 => any. OUTNAME.....The output images name. (Position of max and zero) Output classes are 'AFARrm' and 'AFARam', 'AFARph' or 'AFARre', 'AFARim' OUTSEQ......Output images seq. #. 0 => highest unique. OUTDISK.....Output disk number. 0 => highest with space. DOALIGN.....Controls how the four images are to be aligned (see HELP DOALIGN). True (>.1) means that the images must agree in their coordinates, though not necessarily in the reference pixel position. Alignment is by coordinate values (if DOALIGN > -0.1) or by offsets from the reference pixel positions (if DOALIGN <= -0.1). NOTE: all real axes (>1 point) are aligned. If DOALIGN = -2, the headers are ignored and the images are aligned at pixel (1,1,...). BLC.........Bottom left corner of the 1st input image. TRC.........Top right corner of the 1st input images. (See BLC.) OPCODE......What is recorded to second and third cube? 'CMPL' => real and imaginary at the maximum amplitude position ELSE => the maximum amplitude itself and the phase at the position of the maximum amplitude The position (on the faraday rotation axis) is recorded in the first cube. ICUT........If the amplitude is < ICUT, blank the output position and phase BPARM.......(1) If the peak value is < BPARM(1) then the output will be blanked using value BPARM(2) for RM and BPARM(3) for phase. 0 -> no blanking. (2) Value for blanked pixels in the RM output image. The value -1111 is used to request magic blanks. (3) Value for blanked pixels in the phase output image. The value -1111 is used to request magic blanks. (5) <= 0 -> use a simple 3-point parabolic fit around the maximum amplitude to find the estimated maximum and its location in the RM row = 1 -> use a 5-point least-squares parabolic fit around the maximum amplitude to find the estimated maximum in the the RM row >= 2 -> use the maximum in the row and its position as the estimate. DOHIST......Normally the HI file of input 1 is copied to the output history file and the HI file of the second input is ignored (it will be very similar to the first one). DOHIST >= -2 => copy the first HI file only. DOHIST = -3 => copy no HI file, write AFARS HI only. ----------------------------------------------------------------