4.3 FITS data format

IMAGER is also able to read and write data (images or uv tables) in the FITS format (Flexible Image Transport System).

FITS format being extremely flexible, one should not expect any arbitrary FITS file can be simply ingested into IMAGER: this is possible only for files those information can reasonably be matched into Gildas data format.

Images stored in the primary HDU of FITS files will be handled, as well as UVFITS files. These are files that can be produced by CASA and CLIC.

The FITS access facility is designed as a minimal support. FITS files can only be accessed in ReadOnly mode, or written in full. Thus only READ and WRITE commands should be expected to work in full on FITS files. This can allow quick looks at the data, but for real processing, data should be explicitely converted to Gildas data format. In particular, some commands (including those used by the PIPELINE) may require write access to the data or header, and would fail on FITS files.