[daip] CL ver 1 geodelay calculation problem

Eric Greisen egreisen at nrao.edu
Mon Jul 28 11:01:03 EDT 2008


Walter Brisken wrote:
> For VLBI files, the CL tables have a column called GEODELAY which contains 
> a tabulated listing of the delay model at each CL interval.  I have an 
> example FITS-IDI file, straight off the VLBA hardware correlator, where 
> FITLD results in this column containing nothing but zeros until row 11149, 
> where reasonable values start.  I have confirmed that the two model 
> tables, IM and MC, have valid values for the duration of the file. 
> Removing NX1 and CL1 and running INDXR results in a CL1 table with zero 
> GEODELAY for the entire length of the file.  I have tested FITLD with 
> values of CLINT ranging from 0.016667 to 1 minute, always with similar 
> results.
> 
> This problem exists both in NEW and TST versions and is consistently 
> reproducible.  The file I found that demostrates this problem is:
> 
> /home/parallax/7200001.FITS

I think I see where it is going wrong.  The one FITS file has 2 UV 
tables in it.  The GEODLY values are set for the time range matching the 
2nd table only.  My bet is that it does not do the clean-up pass in the 
first table when there are 2 tables in one file.  That is an error, but...

Eric Greisen





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