<font face="Verdana, Arial, Helvetica" size="2">Eskil Varenius updated #16009<br />
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FRING FRNSRC: MIN FFT IN FREQ REQUESTED 1003040 MAX ALLOWED 262144<br />
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<div style="margin-left: 40px;">Ticket ID: 16009</div>
<div style="margin-left: 40px;">URL: <a href="https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/16009">https://help.nrao.edu/staff/index.php?/Tickets/Ticket/View/16009</a></div>
<div style="margin-left: 40px;">Name: Eskil Varenius</div>
<div style="margin-left: 40px;">Email address: <a href="mailto:varenius@chalmers.se">varenius@chalmers.se</a></div>
<div style="margin-left: 40px;">Creator: User</div>
<div style="margin-left: 40px;">Department: AIPS Data Reduction</div>
<div style="margin-left: 40px;">Staff (Owner): -- Unassigned --</div>
<div style="margin-left: 40px;">Type: Issue</div>
<div style="margin-left: 40px;">Status: Open</div>
<div style="margin-left: 40px;">Priority: Default</div>
<div style="margin-left: 40px;">SLA: NRAO E2E</div>
<div style="margin-left: 40px;">Template group: Default</div>
<div style="margin-left: 40px;">Created: 03 April 2020 12:52 PM</div>
<div style="margin-left: 40px;">Updated: 03 April 2020 12:52 PM</div>
<div style="margin-left: 40px;">Reply due: 07 April 2020 12:52 PM (4d 0h 0m)</div>
<div style="margin-left: 40px;">Resolution due: 29 December 2022 12:00 AM (999d 11h 8m)</div>
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<p>Dear AIPS support,</p>
<p>I run FRING (AIPS 31DEC19) on some S/X-band data with these parameters:</p>
<pre> fring.docalib = -1
fring.calsour = ''
fring.refant = 8
fring.solint = 2
fring.snver = 2
fring.bif=7
fring.eif=16
fring.timeran = 0, 19, 52, 0, 0, 20, 0, 0
</pre>
<pre>and it runs without complaining. However, I want to average IFs together to solve on weak sources. </pre>
<pre>I try aparm(5)=1, but now I get</pre>
<pre>FRING2: Task FRING (release of 31DEC19) begins
FRING2: UVGET: doing no flagging this time
FRING2: Set integration time to 1.000000 seconds, hope that is ok
FRING2: Selecting the data
FRING2: No need to divide by flux densities in this task
FRING2: Determining solutions
FRING2: Writing SN table 2
FRING2: CHKFRQ FOUND 4 INCREMENTS NOT OF THE SAME SIGN
FRING2: WILL TRY SOLUTION ANYWAY - CHECK CAREFULLY
FRING2: Time= 0/ 19 54 59, Polarization = 1
FRING2: FREQUENCIES DO NOT LIE ON A UNIFORM GRID.
FRING2: THIS MAY DEGRADE DETERMINATION OF DELAYS.
FRING2: QINIT: did a GET of 1272252 Kwords, OFF 17465325100633
FRING2: FRNSRC: MIN FFT IN FREQ REQUESTED 1003040 MAX ALLOWED 262144
FRING2: Purports to die of UNNATURAL causes
</pre>
<p>The frequency structure of these S/X-band data may be unusual; it is</p>
<pre>Frequency Table summary uses reference channel 0.62
FQID IF# Freq(GHz) BW(kHz) Ch.Sep(kHz) Sideband Bandcode
1 1 2.22599000 4000.0002 125.0000 1
2 2.24599000 4000.0002 125.0000 1
3 2.26599000 4000.0002 125.0000 1
4 2.29599000 4000.0002 125.0000 1
5 2.34599000 4000.0002 125.0000 1
6 2.36599000 4000.0002 125.0000 1
7 8.20899000 4000.0002 125.0000 1
8 8.21299000 4000.0002 125.0000 1
9 8.25299000 4000.0002 125.0000 1
10 8.44875000 4000.0002 125.0000 1
11 8.46415000 4000.0002 125.0000 1
12 8.46800000 4000.0002 125.0000 1
13 8.47185000 4000.0002 125.0000 1
14 8.48710000 4000.0002 125.0000 1
15 8.48725000 4000.0002 125.0000 1
16 8.49110000 4000.0002 125.0000 1
</pre>
<p>(although I'm only intereted in the X-band part). </p>
<p>Am I doing something wrong, or is this a bug? And what is meant by the lines :</p>
<pre>FRING2: CHKFRQ FOUND 4 INCREMENTS NOT OF THE SAME SIGN
and</pre>
<pre>FRING2: FRNSRC: MIN FFT IN FREQ REQUESTED 1003040 MAX ALLOWED 262144<br /><br />I'm very grateful for any hints.
</pre>
<p>Kind regards (and: I hope you are all fine in these difficult times)</p>
<p>Eskil</p>
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