Object classification

It should, in principle, be possible to classify objects using the PISAFIND parameterisations of a single frame, but, this will only be possible provided that the apparent morphology of subject objects allow it (faint noise-limited objects are unlikely to be distinguishable from stars, and you shouldn't be too disappointed when they are not).

However, given a set of distinguishable objects a classification can be performed. Before such a task can be undertaken it is first necessary to remove the intensity dependency of the parameters. This allows the `shape' for a class of objects to remain reasonably constant. The quality `shape', in this context, really refers to a multivariate function. Usually the only objects on any single frame which have a constant shape are the stars. So the approach adopted in PISA is to `normalize' the PISAFIND parameterisations so that they are referenced to an ideal star. This is the first stage of classification using PISA.