[fitsbits] Packed binary values

We're trying to data formats a new spectral instrument. It will produce
binary tables in a vaguely SDFITS-like format, with a table column
that contains a data array. The array will have multiple axes: time,
frequency, polarization, etc., usually with only the frequency axis
being nondegenerate, with table rows generated (say) once per second.
At moderate data rates, the header information changes slowly compared
to the spectral dump rate, and the time axis may become nondegenerate
within a record. However, at the highest data rates packed binary data
(say 2 bits per sample) will have to be stored, and we're trying to figure
out how to best describe those in a way consistent with "principle of
least astonishment". Do others have experience or suggestions with this?

Thanks,

-Mike

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Mike Nolan +1 787 878 2612x334 Fax: +1 787 878 1861
Arecibo Observatory, HC 3 Box 53995, Arecibo, Puerto Rico 00612 USA