Subject: TAMIN, TAMAX Keywords

From: "Wayne H. Warren Jr. 286-5419" <W3WHW at GIBBS.GSFC.NASA.GOV> (Code 681/GSFC)
Date: Fri, 06 Aug 93 18:18 EDT

leb at hypatia.gsfc.nasa.gov (Lee Brotzman) writes:

>I might suggest, TLMINnnn and TLMAXnnn for "Table Legal Min" and
>"Table Legal Max", respectively.  I think that these keywords are not
>needed as much as the ones mentioned above. It's much more important to
>know the *real* value boundaries then the *expected* boundaries, at
>least in the applications that I can think of.

I prefer TAMINnnn and TAMAXnnn for "allowed" myself, since the other
seems to imply that these "allowed" values could never change for the
same data (plus they remind me of LAWYERS-"sic").  These parameters may
be somewhat less important than the REAL extrema, but for validation
purposes, they can be very useful to discover invalid data.  For
example, in a catalog of stellar parameters, one knows that stellar
radial velocities can never be outside the range +/-300 k/s (just an
example), whereas the actual range might be much smaller and the user
might not be familiar enough with radial velocites to know the "allowed"
values.  Thus, the allowed extrema provide at least a certain amount of
validation for data that cannot be checked at all by any other means.

Wayne H. Warren Jr.
Hughes STX Corporation
Laboratory for Astronomy and Solar Physics
NASA GSFC
w3whw at gibbs.gsfc.nasa.gov