Error and Warning Messages

Except where otherwise stated, the following messages appear on both the command device (typically the terminal) and the report device (typically the file to be printed). The `Log:' information shows the severity and message number which appear in the log file (if one was specified; see Section 4.1).

Can't open file nn

The above message may appear when ASTROM is started and usually means either that the specified data file doesn't exist, or that file protection problems prevent the report file from being written.

Please run ASTROM from the correct script!
ASTROM improperly invoked!
GETARG error!

These are examples of other messages which appear when ASTROM is started and which depend on the particular type of computer being used. They indicate either software errors or some other gross error. Attempting to run the ASTROM executable image directly rather than through the correct command procedure is one possible cause.

^^^^^^ POSSIBLE DATA ERROR? ^^^^^^
(Log: error 1)

This message is output to the command device only. It means that at least one of the fields in the plate centre $[\alpha,\delta\,]$ was suspect - unexpectedly negative, fractional when it should have been integer, or outside the conventional range.

Observation data were incomplete and will be ignored
(Log: error 14)

Many of the observation data may be omitted and have sensible defaults, but certain combinations of omission make it impossible for ASTROM to carry out a reduction in observed place. When this happens, the above message is output and a mean place reduction is carried out.

For the given observation data, the plate centre ZD is xxx.x degrees!
Reduction will be in MEAN place.
(Log: warning 2)

This indicates that the zenith distance of the field centre, if the observation data are to be believed, is greater than $90^{\circ}$. The most likely causes are an incorrectly specified time or observatory site.

sla_DS2TP status n
(Log: error 9)

The above message indicates something badly wrong with the reference star or plate centre positions.

Impossible sla_SVD error!
(Log: error 9)

If this message appears please ask your Starlink Site Manager to contact the Starlink User Support group.

sla_SVD warning n
(Log: warning 3)

Certain very rare combinations of (perfectly valid) data can provoke the above message. If it appears, please check the rest of the output to see if it looks reasonable. If you prefer, you can almost certainly make the condition disappear by changing one of the data values very slightly. If the results look suspect, or if changing the data fails to eliminate the problem, please ask your Starlink Site Manager to contact the Starlink User Support group.

Fit was ill-conditioned!
(Log: warning 4)

This warns that the input data failed to define all the fitted parameters adequately. The cure is to use more reference stars or not to fit the plate centre and/or the distortion.

Radial distortion coefficient cannot reliably be determined!
(Log: warning 6)

This message, which appears only on the report device, warns that the data were of insufficient quality to allow the distortion to be determined. This can happen, for example, if the distortion is very small or if there aren't enough reference stars.

Plate centre cannot reliably be determined!
(Log: warning 8)

The above message, which appears only on the report device, warns that the data were of insufficient quality to allow the plate centre to be determined. This can happen, for example, if the radial distortion is very small or if there aren't enough reference stars.

*************** INVALID DATA ****************
(Log: error 12)

This indicates that there is something fatally wrong with the most recent input record.

------ PREMATURE END OF DATA ------
(Log: error 16)

This indicates that the input file has ended, or that an end-of-sequence record or an end-of-file record has been read at a time when more input records are needed before a plate solution can be attempted.

****** PLATE EPOCH WAS NOT SPECIFIED ******
(Log: error 17)

This happens if no plate epoch is available. This information must be supplied, either as part of the plate data record or in a time record.

****** TOO MANY REFERENCE STARS; MAX n ******
(Log: error 18)

ASTROM internal workspace limits have been reached; reduce the number of reference stars. If you have a legitimate requirement for a larger number of reference stars than is currently allowed, please ask your Starlink Site Manager to contact the Starlink User Support Group.

------ FIT n ABORTED ------

This message always follows one of those described earlier, which will indicate the source of the problem.

----- UNKNOWNS BUT NO SOLUTION ------
(Log: error 19)

An unknown star record has been encountered before the records defining a plate solution have been input. Check the order of records in the input file.

FITS Filename <filename> too long. FITS writing abandoned
(Log: error 10)

The requested FITS header file name is too long (the maximum is around 100 characters).

FITS filename blank!? FITS writing abandoned
(Log: error 11)

The requested FITS headef file name appears to be blank.

Unrecognised FITS WCS style, xxx. FITS writing abandoned
(Log: error 15)

The header style requested is not one of the supported ones. No FITS file will be written.

FITS error detected: ...
(Log: error 13)

The FITS system reported some error (reproduced in the message). FITS writing will be abandoned.