4 Future developments

 4.1 Restrictions and limitations

As a longer-term goal, it might be possible to automate even the discovery of the initial pointing, if there is some reasonable way of estimating plate-centre and plate-scale information ex nihil, from the pattern of objects in the plate.

At present, only one CCD can be processed at a time. It would be useful if the application could process images from multiple CCDs arranged in a mosaic.

4.1 Restrictions and limitations

The script inherits some limitations from ASTROM, and some from CCDPACK’s FINDOFF.

The limitations due to ASTROM are as follows (quoted from SUN/5, Section 5):

ASTROM aims to deliver results better than 1′′ from typical Schmidt plate measurements, and better than 0.1′′ from carefully measured JKT and AAT plates etc. Astrometric specialists will, nonetheless, be aware of a number of shortcomings, including the following:

Despite these limitations, which stem mainly from the need for simplicity of use, the accuracy of the result tends in practice to be dominated by the quality of the input data rather than by ASTROM itself.

Further, ASTROM requires that at least 10 reference stars are available. Since autoastrom obtains its reference stars from well-stocked catalogues, this is not a problem in practice.

The restrictions arising from FINDOFF are similarly slight, and should not be a problem if the initial astrometry is good enough. It’s not at present completely clear exactly what ‘good enough’ means.