[daip] New Client Reply - [!JUM-709073]: HI Imaging with Multiple Spectral Windows in AIPS
John Michael Cannon
do-not-reply at nrao.edu
Wed May 23 10:54:45 EDT 2012
New Client Reply: HI Imaging with Multiple Spectral Windows in AIPS
Hello Eric,
Thanks very much for the suggestions. We have successfully used VBGLU to combine 2 spectral windows and then used NOIFs to allow IMAGR to work properly.
I do have more questions related to this. It seems that the total number of visibilities is being modified during these steps. Here are the details.
1. The two input spectral window (single source) UV databases have the following properties:
AIPS 1: Image=R1/UGC 4 (UV) Filename=UGC4685 .SPT_13. 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=22-MAY-2012
AIPS 1: # visibilities 416894 Sort order TB
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 128 1.4011962E+09 65.00 7.8125000E+03 0.00
AIPS 1: IF 1 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Maximum version number of extension files of type FG is 13
AIPS 1: Maximum version number of extension files of type WX is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value = 0
AIPS 1: Image=R1/UGC 4 (UV) Filename=12A074 .SPT_05. 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=22-MAY-2012
AIPS 1: # visibilities 416663 Sort order TB
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 128 1.4016962E+09 65.00 7.8125000E+03 0.00
AIPS 1: IF 1 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Maximum version number of extension files of type FG is 13
AIPS 1: Maximum version number of extension files of type WX is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value = 0
2. These UV databases are combined using VBGLU to give the following (2 IF) database:
AIPS 1: Image=R1/UGC 4 (UV) Filename=UGC4685 .VBTEST. 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=22-MAY-2012
AIPS 1: # visibilities 416962 Sort order T
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 128 1.4006962E+09 1.00 7.8125000E+03 0.00
AIPS 1: IF 2 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type WX is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Maximum version number of extension files of type FG is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value = 0
Note that the number of visibilities is only slightly larger than the input number of visibilities. I thought that perhaps this was showing only visibilities in one or the other IF, but the number is larger than either of the two inputs. I also note that the sort order goes from TB to T.
I note that the output database has only 1 flag file, which I understand to mean that the highest version FG tables from each input are merged to a single output FG table in the output database. Is this correct?
3. This UV database is put into NOIFs; the output database follows:
AIPS 1: Image=R1/UGC 4 (UV) Filename=UGC4685 .NOIFS . 3
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=23-MAY-2012
AIPS 1: # visibilities 344133 Sort order T
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 192 1.4006962E+09 1.00 7.8125000E+03 0.00
AIPS 1: IF 1 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Maximum version number of extension files of type WX is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value = 0
Now the number of visibilities is significantly reduced from either of the input (original) databases or from the database written out by VBGLU.
---> I thought that perhaps these differences were caused by the FG tables. So, we tested this by using SPLAT to apply the FG tables to the input (single source) single spectral window datasets. We then put these (calibrated, with no FG tables) databases into VBGLU, and then that output into NOIFs. We again have changes in the number of visibilities:
1. The two input spectral window (single source) UV databases (output from SPLAT) have the following properties:
AIPS 1: Image=R1/UGC 4 (UV) Filename=12A074 .SPLAT . 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=23-MAY-2012
AIPS 1: # visibilities 336821 Sort order TB
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 128 1.4011962E+09 65.00 7.8125000E+03 0.00
AIPS 1: IF 1 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value =
AIPS 1: Image=R1/UGC 4 (UV) Filename=12A074 .SPLAT . 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=23-MAY-2012
AIPS 1: # visibilities 336821 Sort order TB
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 128 1.4011962E+09 65.00 7.8125000E+03 0.00
AIPS 1: IF 1 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value =
2. These UV databases are combined using VBGLU to give the following (2 IF) database:
AIPS 1: Got(1) disk= 1 user=7000 type=UV 12A074.VBTEST.1
AIPS 1: Image=R1/UGC 4 (UV) Filename=12A074 .VBTEST. 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=23-MAY-2012
AIPS 1: # visibilities 344133 Sort order T
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 128 1.4006962E+09 1.00 7.8125000E+03 0.00
AIPS 1: IF 2 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
AIPS 1: Keyword = 'CROSSPOW' value = 0
3. This UV database is put into NOIFs; the output database follows:
AIPS 1: Image=R1/UGC 4 (UV) Filename=12A074 .NOTEST. 1
AIPS 1: Telescope=EVLA Receiver=EVLA
AIPS 1: Observer=Jessica User #= 7000
AIPS 1: Observ. date=22-APR-2012 Map date=23-MAY-2012
AIPS 1: # visibilities 344133 Sort order T
AIPS 1: Rand axes: UU-L VV-L WW-L TIME1 BASELINE INTTIM
AIPS 1: ----------------------------------------------------------------
AIPS 1: Type Pixels Coord value at Pixel Coord incr Rotat
AIPS 1: COMPLEX 3 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: STOKES 2 -1.0000000E+00 1.00 -1.0000000E+00 0.00
AIPS 1: FREQ 192 1.4006962E+09 1.00 7.8125000E+03 0.00
AIPS 1: IF 1 1.0000000E+00 1.00 1.0000000E+00 0.00
AIPS 1: RA 1 08 57 01.000 1.00 3600.000 0.00
AIPS 1: DEC 1 13 11 57.000 1.00 3600.000 0.00
AIPS 1: ----------------------------------------------------------------
AIPS 1: Coordinate equinox 2000.00
AIPS 1: Rest freq 0.000 Vel type: OPTICAL wrt LSR
AIPS 1: Alt ref. value 0.00000E+00 wrt pixel 65.00
AIPS 1: Maximum version number of extension files of type NX is 1
AIPS 1: Maximum version number of extension files of type HI is 1
AIPS 1: Maximum version number of extension files of type FQ is 1
AIPS 1: Maximum version number of extension files of type AN is 1
AIPS 1: Keyword = 'MAXABSU ' value = -1.000000E+00
Can you help us understand these changes in the number of visibilities in each step?
Ticket Details
===================
Ticket ID: JUM-709073
Department: AIPS Data Processing
Priority: Default
Status: Open
Link: https://help.nrao.edu/staff/index.php?_m=tickets&_a=viewticket&ticketid=1799
More information about the Daip
mailing list