[daip] New Ticket - [!OJT-697769]: DTSIM bug and explain information errors
James M Anderson
do-not-reply at nrao.edu
Mon Jan 23 05:57:37 EST 2012
New Ticket: DTSIM bug and explain information errors
DTSIM seems to have problems related to right-handed coordinate systems when inserting antenna information from its DTPARM.FOR information.
Using an input file with:
AN_TABLE VER=1 /
STATION = 'ALL_VLBA' /
! STATION = 'EB' MNT='AZEL' CARTPOS= 4033947.4242,486990.5601,4900430.8386 /
END /
and then dumping the information out with PRTAN, I see
vlb054 PRTAN(31DEC12) 100 23-JAN-2012 11:45:54 Page 1
File=VLBI .TESTUV. 2 An.ver= 1 Vol= 1 User= 100
Array= Freq= 22000.000000 MHz Ref.date= 01-FEB-2012
Array reference position in meters (Earth centered)
Array BX= 0.00000 BY= 0.00000 BZ= 0.00000
Polar X = 0.00000 Polar Y = 0.00000 arcsec
Earth rotation rate = 360.9856449672 degrees / IAT day
GST at UT=0 = 130.6194032219 degrees
UT1-UTC= 0.0000000 Data time(UTC )-UTC= 0.0000000 seconds
XYZHAND = 'RIGHT ' TFRAME = '
Solutions determined for FREQID 1
Mount=ALAZ Axis offset= 0.0000 meters IFA IFB
Feed polarization type = R L
Ant 1 = VLBA_PT BX= -1640953.6250 BY= -5014816.0000 BZ= 3575411.7500
Ant 2 = VLBA_KP BX= -1995678.5000 BY= -5037318.0000 BZ= 3357328.0000
Ant 3 = VLBA_LA BX= -1449752.2500 BY= -4975298.5000 BZ= 3709124.0000
Ant 4 = VLBA_BR BX= -2112064.7500 BY= -3705356.5000 BZ= 4726814.0000
Ant 5 = VLBA_FD BX= -1324009.0000 BY= -5332182.0000 BZ= 3231962.5000
Ant 6 = VLBA_SC BX= 2607848.5000 BY= -5488070.0000 BZ= 1932739.5000
Ant 7 = VLBA_NL BX= -130872.1250 BY= -4762317.0000 BZ= 4226851.0000
Ant 8 = VLBA_OV BX= -2409150.0000 BY= -4478573.5000 BZ= 3838617.2500
Ant 9 = VLBA_MK BX= -5464075.0000 BY= -2495249.2500 BZ= 2148296.7500
Ant 10 = VLBA_HN BX= 1446375.2500 BY= -4447940.0000 BZ= 4322306.0000
All of this looks ok, with negative y coordinate values for the VLBA in a right-handed coordinate system, as reported by PRTAN.
But, when I add an extra station on, using
AN_TABLE VER=1 /
STATION = 'ALL_VLBA' /
STATION = 'EB' MNT='AZEL' CARTPOS= 4033947.4242,486990.5601,4900430.8386 /
END /
in the input file, I get
vlb054 PRTAN(31DEC12) 100 23-JAN-2012 11:48:02 Page 1
File=VLBI .TESTUV. 1 An.ver= 1 Vol= 1 User= 100
Array= Freq= 22000.000000 MHz Ref.date= 01-FEB-2012
Array reference position in meters (Earth centered)
Array BX= 0.00000 BY= 0.00000 BZ= 0.00000
Polar X = 0.00000 Polar Y = 0.00000 arcsec
Earth rotation rate = 360.9856449672 degrees / IAT day
GST at UT=0 = 130.6194032219 degrees
UT1-UTC= 0.0000000 Data time(UTC )-UTC= 0.0000000 seconds
XYZHAND = 'RIGHT ' TFRAME = '
Solutions determined for FREQID 1
Mount=ALAZ Axis offset= 0.0000 meters IFA IFB
Feed polarization type = R L
Ant 1 = VLBA_PT BX= -1640953.6250 BY= 5014816.0000 BZ= 3575411.7500
Ant 2 = VLBA_KP BX= -1995678.5000 BY= 5037318.0000 BZ= 3357328.0000
Ant 3 = VLBA_LA BX= -1449752.2500 BY= 4975298.5000 BZ= 3709124.0000
Ant 4 = VLBA_BR BX= -2112064.7500 BY= 3705356.5000 BZ= 4726814.0000
Ant 5 = VLBA_FD BX= -1324009.0000 BY= 5332182.0000 BZ= 3231962.5000
Ant 6 = VLBA_SC BX= 2607848.5000 BY= 5488070.0000 BZ= 1932739.5000
Ant 7 = VLBA_NL BX= -130872.1250 BY= 4762317.0000 BZ= 4226851.0000
Ant 8 = VLBA_OV BX= -2409150.0000 BY= 4478573.5000 BZ= 3838617.2500
Ant 9 = VLBA_MK BX= -5464075.0000 BY= 2495249.2500 BZ= 2148296.7500
Ant 10 = VLBA_HN BX= 1446375.2500 BY= 4447940.0000 BZ= 4322306.0000
Ant 11 = EB BX= 4033947.4242 BY= 486990.5601 BZ= 4900430.8386
where now the VLBA antennas have the wrong sign for the y coordinate, in a right-handed coordinate system, and PRTAN says that this is a right-handed coordinate system.
Inside of DTPARM.FOR, the coordinates are entered in a right-handed coordinate system, but then get converted or not depending on certain cases. Should everything just be made always right-handed?
Next, the EXPLAIN file does not match the code for DTSIM (DTPARM). The EXPLAIN information says that giving STATION = 'SPEC_NAM' for the special VLA codes
VLA_Yx will give VLA antennas for array configurations x. But, the DTPARM code expects this to be called ALL_Yx.
Have a good day,
James M Anderson
Ticket Details
===================
Ticket ID: OJT-697769
Department: AIPS Data Processing
Priority: Default
Status: Open
Link: https://help.nrao.edu/staff/index.php?_m=tickets&_a=viewticket&ticketid=1399
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