Calibration

For a new instrument all that is required is to specify a new set of rules and work out what to do with the `best' calibration that is returned. For UFTI this simply means that the name is returned to the primitive for use. For SCUBA more complex routines are required for sky opacity calibration since the number returned by the index file is sometimes modified for different filters before being returned to the user (the SCUBA calibration system never returns a file name).

For every type of calibration, the calibration object (ORAC::Calib and sub-classes) must provide the following methods:

1.

A method for returning the current calibration observation that matches the criteria. This method should be an obvious name related directly to the calibration (e.g. `dark', `skydip').

2.

A method for retrieving the ORAC::Index object associated with the relevant index file. The name of this method should be related to the name of the index file (e.g. skydipindex will access the file index.skydip).

3.

A method to prevent the pipeline from overwriting the current calibration (used when the user is overriding a certain calibration from the command line). This will be called, for example, darknoupdate(). oracdr assumes that the method is of this form since this method will be called whenever a user makes use of the -calib switch,