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<DIV> </DIV>
<DIV>
<DIV>ͯ·æÏÍ wrote:</DIV>
<DIV>> </DIV>
<DIV>>
> > This is a bit curious - FITLD builds the initial calibration table (CL</DIV>
<DIV>>
> > version 1) from iinformation in the MC and IM tables. This message </DIV>
<DIV>>
> > says that there are times in the CL table for which there was no MC </DIV>
<DIV>>
> > table data within 1 minute. You could try PRTAB on the CL table and </DIV>
<DIV>>
> > examine the clock and atmosphere columns. I suspect that normally they </DIV>
<DIV>>
> > contain only zeros and, if so, this message contains nothing </DIV>
<DIV>>
> > significant. If they are not zero, then it might be good to find the </DIV>
<DIV>>
> > relevant times and fix up the CL table manually.</DIV>
<DIV>> > </DIV>
<DIV>> > </DIV>
<DIV>> > Thank you!</DIV>
<DIV>> > </DIV>
<DIV>>
> I have tried to use "PRTAB" to print 'CL' table, and the values of clock </DIV>
<DIV>>
> and atmosphere columns were zeros. I set the values of 'clock' and </DIV>
<DIV>>
> 'atmosphere' to zeros in 'MC' and 'IM' tables in my fits file. As you </DIV>
<DIV>>
> say "I suspect that normally they contain only zeros and, if so, this </DIV>
<DIV>>
> message contains nothing significant.", that mean only the value of </DIV>
<DIV>>
> 'clock' and 'atmosphere' columns in "CL" table which did not get clock </DIV>
<DIV>>
> and atmosphere, were zeros and nothing significant?</DIV>
<DIV>> > </DIV>
<DIV>> > </DIV>
<DIV>>
> But, I use 'FITLD' (AIPS version '31DEC13' )to load fits file, sometimes </DIV>
<DIV>>
> there were no warnings at all (just like 'no_warning.FITS' in attachment),</DIV>
<DIV>>
> sometimes I got some warnings "MC2CL: WARNING 8 CL RECORDS DID NOT GET </DIV>
<DIV>>
> CLOCK AND ATMOSPHERE" (just like 'have_warnings.FITS' in attachment). </DIV>
<DIV>>
> The fits files in attachment were created by me, maybe there're some </DIV>
<DIV>> > bugs in my fits files.</DIV>
<DIV>> > </DIV>
<DIV>>
> I'm wondering how the 'MC2CL' work ,and which information do the 'MC2CL' </DIV>
<DIV>>
> use in the 'MC' and 'IM' tables.</DIV>
<DIV>> </DIV>
<DIV>>
MC2CL simply copies the clock and atmosphere corrections that were</DIV>
<DIV>>
applied by the correlator into the CL table. In general, these</DIV>
<DIV>>
corrections are not known at correlation time and so are zero in the MC</DIV>
<DIV>> table and thus in the CL table.</DIV>
<DIV>> </DIV>
<DIV>>
Your example FITS file did however expose an error in the handling of</DIV>
<DIV>>
the MC table (and potentially the IM table). The fact that your MC</DIV>
<DIV>>
table records were separated by < 2 seconds caused the fetching routine</DIV>
<DIV>>
to fail to find the records which were present in the MC table. I have</DIV>
<DIV>>
corrected the code and, if you run a MNJ on Tuesday in 31DEC14, you will</DIV>
<DIV>>
get the corrected version. Note that there is no error since the data</DIV>
<DIV>> to be fetched was all zero.</DIV>
<DIV>></DIV>
<DIV>>
The IM2CL routine gets the geometric delay and dispersion terms applied</DIV>
<DIV>>
by the correlator. The former are not zero, the latter are usually</DIV>
<DIV>>
zero. Fortunately, the similar error for IM tables was only triggered</DIV>
<DIV>>
by IM records closer than 1 second and so did not occur with your data.</DIV>
<DIV>> </DIV>
<DIV>>
Thanks you for following up on this matter</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>Thank you for your patience reply.</DIV>
<DIV> </DIV>
<DIV>Am I must upgrade to AIPS(version <SPAN
style="COLOR: #ff0000">31DEC</SPAN><SPAN
style="COLOR: #ff0000; FONT-SIZE: 14pt; FONT-WEIGHT: bold">14</SPAN>)? Is that
ok if I still use AIPS(version <SPAN style="COLOR: #ff0000">31DEC</SPAN><SPAN
style="COLOR: #ff0000; FONT-SIZE: 14pt; FONT-WEIGHT: bold">13</SPAN>)?</DIV>
<DIV> </DIV>
<DIV>you said," The fact that your MC table records were separated by <SPAN
style="COLOR: #ff0000">< </SPAN><SPAN style="COLOR: #ff0000">2 seconds</SPAN>
caused the fetching "....."Fortunately, the similar error for IM tables was only
triggered by IM records <SPAN style="COLOR: #ff0000">closer than <SPAN
style="COLOR: #ff0000">1 second</SPAN> </SPAN>and so did not occur with your
data". Maybe you mean <SPAN style="COLOR: #ff0000">"< 2
minutes</SPAN><SPAN style="COLOR: #ff0000">" ,"<SPAN
style="COLOR: #ff0000">closer than <SPAN style="COLOR: #ff0000">1
minute"</SPAN></SPAN><SPAN style="COLOR: #000080">? </SPAN></SPAN></DIV>
<DIV><SPAN style="COLOR: #ff0000"><SPAN
style="COLOR: #000000"></SPAN></SPAN> </DIV>
<DIV><SPAN style="COLOR: #ff0000"><SPAN style="COLOR: #000080">I have separated
the MC table records by nearly 5 minutes before, and I got the same warnings
(MC2CL: WARNING ...). So, I separated MC table records by every 2 minutes
if the SCAN of a observation was longer than 2 minutes( usually
the SCAN of a observation was 5 minutes), but if the SCAN
time was shorter than 2 minutes I sepparated MC table records by the
SCAN time.</SPAN></SPAN></DIV>
<DIV> </DIV>
<DIV>
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<DIV><SPAN>
<DIV><SPAN style="FONT-FAMILY: ËÎÌå; COLOR: #000000; FONT-SIZE: 10.5pt">
<DIV style="FONT-FAMILY: Verdana; COLOR: #000; FONT-SIZE: 14px">
<DIV><SPAN style="COLOR: #808080">Fengxian Tong.</SPAN></DIV>
<DIV><SPAN style="COLOR: #808080">Shanghai Astronomical Observatory, CAS, 80
Nandan Road, 200030,Shanghai </SPAN></DIV>
<DIV><SPAN style="COLOR: #808080">TEL:
+86-21-3477-5512</SPAN></DIV></DIV></SPAN></DIV></SPAN></DIV></DIV>
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