Subject: Re: VLBA UV-data FITS test files

From: dwells at azalea.cx.nrao.edu (Don Wells)
Date: Mon, 6 Jul 1992 22:39:05 GMT

In article <1992Jun27.034259.18877 at cco.caltech.edu>
mcs at goblin.caltech.edu (Martin Shepherd) writes: "... I have just been
reading the draft proposal for the new FITS format for interferometer
UV data exchange. Does anybody know if there are any FITS test files
in this format - available by anonymous ftp?..."

anonFTP fits.cx.nrao.edu[192.33.115.8]:/FITS/SampleData/VLBA contains:

       1485 Jul  6 16:19 README
     318012 Jun 19 12:32 VLBA_format.ps
    8663040 Jun 23 16:23 j000015.fits
      12426 Jul  6 15:40 j000015.lis

The README says:

		-*- Sample VLBA distribution file -*-

The FITS file in this directory, j000015.fits, was produced by the
VLBA Correlator in late June 1992, just before the machine was
disassembled for shipment to New Mexico.  The file contains fringe
visibilities from an astronomical source observed by a five-station
array in early April. The file format is described in the document
VLBA_format.ps; it is a set of binary tables ('BINTABLE' extensions).
Current TST versions of AIPS are said to be able to read this file.

Those who are interested solely in the header syntax, not in the
visibility data, should get the file j000015.lis, which contains an
ASCII listing of the headers of all the tables plus size information
for the binary records.

This sample distribution file does *not* conform exactly to the format
described in the document. In particular, the UV data table does not
have the integration time column which is specified in the document.
Both the document and the file format should be regarded as *DRAFT*;
details will be subject to change in the coming months.

Send comments or questions about the VLBA format to John Benson
(jbenson at nrao.edu) and/or Phil Diamond (pdiamond at nrao.edu).
--

Donald C. Wells             Associate Scientist        dwells at nrao.edu
National Radio Astronomy Observatory                   +1-804-296-0277
520 Edgemont Road                                 Fax= +1-804-296-0278
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