SMA Data Errors and MIR Fixes

Here I summarize the SMA data errors (up to 2010 Feb 28 since 2005) and MIR fixes. Note this is still an incomplete list.

• Time Sensitive Fix
  1. Rest frequency header problem

     SMA Log:

     19656

     Duration:

     2009 Dec 18 – 2010 Jan 10

     Symptom:

     wrong velocity axis when imaging any lines in s25→s48

     Fix:

     before the data is output to miriad or fits (xxx as target name):

      IDL> select,source='xxx',band='s01',/p,/re
      IDL> temp=sp[psf[0]].rfreq
      IDL> select,source='xxx',/p,/re
      IDL> sp[psf].rfreq=temp
           

  2. Velocity header problem

     SMA Log:

     19413

     Duration:

     all double bandwidth data taken before 2009 Nov 28

     Symptom:

     wrong velocity axis when imaging any lines in s25→s48

     Fix:

     before the data is output to miriad or fits:

      IDL> select,/p,/re
      IDL> uti_if2vel_fix
           

  3. Diurnal doppler correction disabled

     SMA Log:

     17621

     Duration:

     all eSMA tracks taken around 2009 Mar 25

     Symptom:

     blurred spectra

     fix:

     before the data is output to miriad or fits

      IDL> select,/p,/re
      IDL> uti_doppler_fix,source='xxx',/diurnal 
           

  4. Frequency labeling problem

     SMA Log:

     14506, 14628

     Duration:

     all data taken before 2007 Nov 26

     Symptom:

     half channel frequency error in all bands

     Fix:

     before the data is output to miriad or fits

      IDL> uti_fqhdr_fix
           

  5. DopplerTrack velocity shift disabled

     SMA Log:

     9294, 9309, 9324

     Duration:

     2004 Dec 10 – 2005 Apr 29

     Symptom:

     blurred spectra

     Fix:

     before the data is output to miriad or fits

      IDL> uti_erot_fix
           

• General Fix
  1. UVW header problem

     SMA Log:

     7820, 17610, 17885, 18037

     Symptom:

     UVW coords have zero values. The cause of the problem is unknown. Although MIR readdata program will check uvw coordinates when loading data into IDL and automatically fix the problem if they are wrong, it is still possible some will slip past the check and the users will have to fix the problem by themselves.

     Fix:

     before the data is output to miriad or fits:

      IDL> select,/p,/re
      IDL> uti_blneu_fix, 'antennas'
      IDL> uti_uvw_fix 
           

  2. eSMA calibration

     SMA Log:

     17621

     Symptom:

     Receiver header problem for baseline 9-10; phase drift due to CSO non-intersection of axes.

     Fix:

     right after loading the data into idl:

      IDL> bl.irec=1
      IDL> select,/p,/re
      IDL> sma_cal_bas, ntel=10, csoda=4.4 
           

  3. Velocity fix for non-dopplerTracked sources

     SMA Log:

     15032, 17603

     Symptom:

     not data problem but incorrect velocity axis for the sources which are not ’dopplerTrack’ed in multiple sources observation.

     Fix:

     before the data is output to miriad or fits:

      IDL> select,/p,/re
      IDL> uti_doppler_fix, source='xxx', ref='maintarget'
         where maintarget is the 'dopplerTrack'ed source. 
           

  4. Velocity header problem

     SMA Log:

     8081

     Symptom:

     wrong velocity axis for some bands but good on other bands. cause unknown.

     Fix:

     before the data is output to miriad or fits:

      IDL> select,/p,/re
      IDL> uti_vel_fix, band='s02',ref='s03'
                which will use s03 as the reference header to fix
         the velocity header for s02
           

  5. Wrong Hour Angle values

     SMA Log:

     no

     Symptom:

     wrong HA values, which will affect UVW coord calculation. cause unknown.

     Fix:

     after loading data into IDL:

      IDL> uti_ha_fix
           

This document was translated from L^AT_EX by H^EV^EA.