[daip] forwarded message from Daniel Lebach

[Eric Greisen]

------- start of forwarded message (RFC 934 encapsulation) -------
Content-Type: text
Received: from polaris.cv.nrao.edu (polaris.cv.nrao.edu [192.33.115.101])
	by zia.aoc.NRAO.EDU (8.9.3/8.9.3) with ESMTP id NAA13215
	for <egreisen at aoc.nrao.edu>; Tue, 24 Sep 2002 13:01:54 -0600 (MDT)
Received: from cv3.cv.nrao.edu (cv3.cv.nrao.edu [192.33.115.2])
	by polaris.cv.nrao.edu (8.9.3/8.9.3/CV-SOL-3.0) with ESMTP id PAA16867
	for <egreisen at polaris.cv.nrao.edu>; Tue, 24 Sep 2002 15:01:53 -0400 (EDT)
Received: from cfa.harvard.edu (cfa.harvard.edu [131.142.10.1])
	by cv3.cv.nrao.edu (8.11.6/8.11.6) with ESMTP id g8OJ1pQ04504
	for <egreisen at cv3.cv.nrao.edu>; Tue, 24 Sep 2002 15:01:51 -0400
Received: from gyro.harvard.edu (gyro [131.142.25.132])
	by cfa.harvard.edu (8.9.2/8.9.2/cfunix Mast-Sol 0.5) with ESMTP id PAA14639
	for <egreisen at cv3.cv.nrao.edu>; Tue, 24 Sep 2002 15:01:50 -0400 (EDT)
Received: (from del at localhost)
	by gyro.harvard.edu (8.9.2/8.9.2/cfunix S 0.5) id PAA21251
	for egreisen at cv3.cv.nrao.edu; Tue, 24 Sep 2002 15:01:50 -0400 (EDT)
Message-Id: <200209241901.PAA21251 at gyro.harvard.edu>
X-MailScanner: Found to be clean
From: Daniel Lebach <dlebach at cfa.harvard.edu>
To: egreisen at cv3.cv.nrao.edu
Subject: Re: [daip] possible errors in CLCOR parallactic angle corrections (OPCOD 'PANG')
Date: Tue, 24 Sep 2002 15:01:50 -0400 (EDT)


Hi Eric,

The experiment from which the data in the postcript plots of my last
e-mail came is BR071D, obs. on 21 Dec. 2001.  (I hope you saw those
plots.)

Let me emphasize that the discrepancy between RCP and LCP phases
becomes highly noticeable only when an observed source is passing
very nearly overhead, i.e., near 90 degrees elevation.  Further, the
problem might occur only when the antenna must slew between different
sources at these high elevations (and hence spin a lot in azimuth);
that is the only circumstance under which I have had high-elevation
data to assess the problem.

Good luck.

Dan

> From: Eric Greisen <egreisen at cv3.cv.nrao.edu>
> Date: Tue, 24 Sep 2002 11:43:16 -0600
> To: Dan Lebach <del at cfa.harvard.edu>
> Subject: Re: [daip] possible errors in CLCOR parallactic angle corrections (OPCOD 'PANG')
> 
> I have looked at the information you have sent.  Can you tell us the
> experiment number/code for one of the experiments that show this
> affect?  We want to look at certain plots from the PC table to see if
> there is evidence of cable problems etc.  I have looked at CLCOR and
> other than some issue about perhaps not updating the parallactic angle
> often enough, I see no real problem.  But there may be hardware or
> logic problems elsewhere in the system.
> 
> Thanks
> 
> Eric Greisen
> 

------- end -------