[daip] Fwd: Problems loading FITS data into AIPS

[Eric Greisen]

Richard Townsend wrote:
> Hi,
> 
> So I installed AIPS for the very first time yesterday, and, although it 
> took me quit a while, I finally got it up and running without any error 
> messages. My main goal with this piece of software is to display images 
> similar to the graphs in chapter 6 of the cookbook. However, I have run 
> into some issues in trying to read a FITS file in AIPS. Following the 
> various instructions as well as I could, here is the background info of 
> my problem:
> 
> I am running Ubuntu, if that makes a huge difference.
> 
> The file I am trying to read is called sequence29.fits and it is in the 
> directory /home/rtownsend/Dowloads/. In my terminal, I did:
> 
> $MYAREA=/home/rtownsend/Downloads; export MYAREA
> 
> Then, while running AIPS, I did the following:
> 
> TASK 'FITLD'
> DATAIN 'MYAREA:SEQUENCE29.FITS'
> GO
> 
> The got the following output in my MSGSRV window:
> 
> localh> FITLD1: Task FITLD (release of 31DEC10) begins
> localh> FITLD1: Create FITLD             .TEMP     .    1 (MA)   on 
> disk  1  cno   1
> localh> FITLD1: TAPIO: RECORD LENGTH    128 INCONSISTENT WITH BLOCK SIZE 
> 2880
> localh> FITLD1: IMGDAT: COULD NOT READ INPUT.   IER=   10
> localh> FITLD1: ERROR     1 RETURNED FROM IMGTAP
> localh> FITLD1: Destroyed  1 extension files of type HI
> localh> FITLD1: Destroyed MA image file: catno=    1 disk=1
> localh> FITLD1: Purports to die of UNNATURAL causes
> localh> FITLD1: localhos 31DEC10 TST: Cpu=     0.0  Real=     0  
> IO=             1
> 
> I assume that the fourth line of output means that the task failed, but, 
> unfortunately, I couldn't find any documentation to explain to me what 
> TAPIO or IMGDAT refers to. If you could offer any help at all that would 
> be fantastic. To reiterate, I am trying to read the data from the file 
> sequence29.fits, and then plot it on a graph. I will attach the file in 
> case that is the problem. Thank you!

You assume correctly that it failed.  The file you attached is not an 
integer times 2880 bytes in length and so is not a valid FITS file.  Did 
you remember to say binary when you ftp'ed the file or did the copy fail 
in some way?  Things like TAPIO and IMGDAT are internal names that help 
us debug things should real debugging be required.  The record length 
message is what was important here.

I took a bit more of a look and the file size is exactly 2880 + 
2*512*512 bytes long.  This suggests that the FITS writing software did 
not pad out the last record to 2880 bytes which is a requirement.

Eric Greisen


Eric Greisen