Log output

The log file is a report on ASTROM's actions and results which is easy to parse, and thus easy for another program, acting as a harness for ASTROM, to find out about ASTROM's progress.

The log file consists of a number of statements describing the fits ASTROM has performed, and its success. The statements describing each fit are bracketed in a pair of statements `FIT $\langle n\rangle$' and `ENDFIT', for some fit number  $\langle n\rangle$. The statements thus bracketed are in table 1.

Table 1: Log file statements

Result	RESULT keyword value
Status	STATUS [OK | BAD]
Residuals	RESIDUAL source-number dx dy dr
Information	INFO code details...
Warnings	WARNING code comment
Errors	ERROR code comment

The INFO, WARNING and ERROR statements share a common set of codes, and are described in Appendix D.

The RESIDUAL message reports the size of the residuals for the given source number in the input file. The residuals are reported in the x and y directions, plus $\delta r=\sqrt{\delta x^2+\delta y^2}$.

The STATUS message is OK if the fit succeeded, and BAD otherwise.

The RESULT statements give feedback about the results of the fit. Much of the information is also in the FITS WCS headers, if they are generated. The keywords are listed in table 2.

Table 2: Information returned in log-file RESULT statement

keyword	meaning
nstars	number of ref stars
xrms	RMS errors in fitted x, arcsec
yrms	...in y
rrms	...in r
plate	(mean) plate scale, arcsec
prms	rrms in pixels
nterms	number of terms in fit
rarad	projection pole RA, radians
decrad	projection pole Dec, radians
rasex	projection pole RA, sexagesimal
decsex	projection pole Dec, sexagesimal
wcs	name of FITS WCS header file