[evlatests] Modcomp-free: L-Band

[rperley at nrao.edu]

Some clarification is needed here.

With Modcomps in control, I know from long experience that there are no
data available while antennas are slewing, as I have always done the test
with all flags ignored.  Either the correlator is off, or a flag not
accessible to AIPS has been used (if such a thing exists).

When filling Modcomp-free data, I note I get a continual stream of data
(with the same flag controls in AIPS turned off), regardless of whether
the antennas are moving or not.

Something is different between the systems, I claim.

Whether the correlator products should be blocked from the archive during
antenna slews is an interesting question.  I suspect not, for you never
know what the antennas might see on their journey ...


> On Thu, 14 Jun 2007, Rick Perley wrote:
>
>>    1) The first 1.25 minutes of the scan were all noise -- evidently
>> the correlator was outputting data even though the antennas were slewing
>> from the previous source (3c147 at P-band ) to the L-band source
>> (3C84).  I thought the correlator was supposed to be turned off when the
>> antennas were slewing ...
>
> Data is not surpressed while the antennas are slewing, but it
> should be flagged.  It would be interesting to look at that
> because we have seen curiosities in flags today while antennas
> were slewing.
>
> I don't know that doing this was a conscious decision.  If it
> is deemed desireable idcaf could probably be taught to do it.
>