The approach and OGIP standard format for storing PHA data
for spectral analysis is outlined and discussed. We describe the
formats for both a file containing a single PHA dataset and the
more general case of a file containing multiple datasets from the
The requirements imposed on the resultant PHA file such that response
matrices etc. can be easily constructed are also outlined.
Intended audience: primarily OGIP programmers, hardware teams & authors
of spectral analysis s/w.