[fitsbits] Potential new compression method for FITS tables

[Preben Grosbol]

On Thursday 16 December 2010 14:42:51 Mark Taylor wrote:
> Although it doesn't say so explicitly, I presume since there's no
> indication otherwise that tables encoded in the way described by this
> document are still XTENSION = 'BINTABLE'.  I think this is problematic,
> since a table reader which is unaware of this convention may encounter
> such a FITS extension, see that it's a BINTABLE, and believe that it can
> make sense of it.
Hi Mark,
 I can second your concern.  We have had the discussion before in the 80's
with the blocking convention. I believe it to be important that old readers,
not knowing new conventions, are not mislead.  As a minimum, it should be
trivial for the end user (e.g. by reading the header keywords) to understand
why data are not read correctly.

As a side comments, I participated in a meeting for general archives a few
years ago.  There they did not recommend to save compress data since
the effect of single bit errors is more serious than for raw data, not
justifying the gain of disk space.

Preben Grosbol