[daip] [forwarded from Shinji Horiuchi] FITLD errors

[Eric Greisen]

 >   I have a question on FITLD. I have a VSOP experiment recorded in VLBA 
 > format, copied to S2 and correlated at Penticton. This is a spectral line 
 > experiment with 8192 channels for each of 2 IFs. As in the following email 
 > to Penticton I can not load the FITLD file by FITLD, and Penticton people 
 > do not know why. The error message says "chans   16384 too many, get AIPS 
 > Manager ". Does AIPS has limit in number of channels to deal with FITLD? 
 > Thank you in advance for answering to this question.
 > 
 > >  FITLD1: Sky frequencies (MHz) before re-ordering occurs:
 > >  FITLD1: Incoming FREQID #   1
 > >  FITLD1:  1608.00   1655.00
 > >  FITLD1: IMREF1: NUMBER KEYWORDS  51 NOT EXPECTED 12
 > >  FITLD1: CL table interval set at  1.00 minutes
 > >  FITLD1: GET3DT: # pol * IF * chans   16384 too many, get AIPS Manager
 > >  FITLD1: UT2UV: ERROR   1 TRANSLATING UV BINARY TABLE
 > >  FITLD1: ERROR      1 RETURNED FROM BTRTAB
 > >  FITLD1: Purports to die of UNNATURAL causes
 > >
 > >Then I tried to reduce the number of IFs and channels to load with FITLD 
 > >inputs BIF,EIF or BCHANNEL, ECHANNEL, but it always ended up with the same 
 > >results. What do you suggest to do? Could you make sure if you can load 
 > >the data into AIPS at Penticton?
 > >

There are limits to various parameters in AIPS becuase array and
buffer sizes must be allocated in advance in Fortran.  For some reason
- presumably limits in the VLBA Correlator and small thinking on the
part of FITLD's author - the limits in FITLD were not those in the
rest of AIPS.  I have changed the standard version to use the standard
limits which would (just) encompass your observation.

Since these limits control the size of buffers which must be used to
read your data before channel/IF selection, the adverbs cannot help
you.

Eric Greisen

The Relevant part of the new FITLD:

LOCAL INCLUDE 'PFITLD.INC'
      INCLUDE 'INCS:PUVD.INC'
      INTEGER   MAXFQI, LMXCHA, LMXCIF, LTARSZ
C                                       MAXFQI=max number FREQ ID's
      PARAMETER (MAXFQI = MAXFQ)
C                                       check the sizes carefully in
C                                       SCRTCH.INC below
C                                       MAXCHA for data read by FITLD
      PARAMETER (LMXCHA=MAXCHA)
C                                       MAXCIF for data read by FITLD
C                                       max (#pols * #chans * #IFs)
      PARAMETER (LMXCIF=MAXCIF)
C                                       LTARSZ = max local table size
C                                       is for BP tables (+6 extra)
      PARAMETER (LTARSZ=XBPRSZ)
LOCAL END