[daip] zenangle problem?

[Eric Greisen]

bob at physics.ucdavis.edu wrote:
>  hi, i am running imagr on data from 1994.
> imagr is calculating a zenangle og 91.4 degrees.
> 
> unless i don't understand what zenangle is, this is
> not possible.
> 
> any comments
> 
> 
> bob
> 
> ps below see imhead for the image
> 
>> imhe
> AIPS 4: Image=10015+32  (MA)         Filename=10015+32552 .ICL001.   2
> AIPS 4: Telescope=VLA                Receiver=VLA
> AIPS 4: Observer=AB628               User #=  326
> AIPS 4: Observ. date=14-JUN-1994     Map date=30-JUN-2009
> AIPS 4: Minimum=-2.56503583E-03      Maximum= 1.75535306E-02 JY/BEAM
> AIPS 4: ----------------------------------------------------------------
> AIPS 4: Type    Pixels   Coord value     at Pixel     Coord incr   Rotat
> AIPS 4: RA---SIN   512    10 01 29.933     256.00         -1.800    0.00
> AIPS 4: DEC--SIN   512    32 55 12.000     257.00          1.800    0.00
> AIPS 4: FREQ         1   1.4000000E+09       1.00  4.3750000E+07    0.00
> AIPS 4: STOKES       1   1.0000000E+00       1.00  1.0000000E+00    0.00
> AIPS 4: ----------------------------------------------------------------
> AIPS 4: Coordinate equinox 2000.00
> AIPS 4: Map type=NORMAL              Number of iterations=      10
> AIPS 4: Conv size=   5.40 X   5.40   Position angle=   0.00
> AIPS 4: Rest freq      0.000         Vel type: OPTICAL wrt YOU
> AIPS 4: Alt ref. value  1.12500E+05  wrt pixel    1.00
> AIPS 4: Maximum version number of extension files of type CC is   1
> AIPS 4: Maximum version number of extension files of type HI is   1
> AIPS 4: Keyword = 'CCFLUX  '  value =  1.369117E-02
> AIPS 4: Keyword = 'CCTOTAL '  value =  1.369117E-02
> AIPS 4: Keyword = 'PARANGLE'  value =  3.217584E-01
> AIPS 4: Keyword = 'ZENANGLE'  value =  9.145541E+01
> 

I agree that this appears odd.  I think that the UV data format has not 
changed so I suspect the times are okay (an IMH of the uV would reassure 
me of this).  Try PRTUV for a page on the 2 data sets.  I would wonder a 
bit however about the AN files and the SU tables (if any).

Eric Greisen

P.S.  These are not used except for snapshots where OGEOM could re-grid 
correcting the geometry if there were an offset.