Obstap / fixed

[Douglas Tody]

On Wed, 16 Mar 2011, Francois Bonnarel wrote:

> Douglas Tody a e'crit :
>> On Wed, 16 Mar 2011, Francois Bonnarel wrote:
>> 
>>> On the obs_title discussion:
>>> -----------------------------------------------
>>> 
>>> /As far as I understand obs_title is a free text description. Maybe 
>>> usefull but the field name is confusing I think. Nothing to do with an 
>>> ID./
>> 
>> Note that this is already in the data model (SSA/Spectrum) with the
>> name "title": DataID.Title. It is also in SIA1 (VOX:Image_Title).
>> In both cases it is mandatory metadata. The name derives from FITS
>> where it is commonly used for image data. It is not an identifier
>> in the usual sense, but is part of dataset identification, providing
>> a human readable, free text (but short) description of the dataset.
>> This is commonly used in analyis software to e.g. describe a dataset in
>> a query response table, in a plot header, in the label of a displayed
>> image, and so forth.
>> 
>> - Doug
> OK Doug, I noticed that.
> But we may play a little bit with the name/utype match
> keep it "utyped" by DataID.title and use "obs_descr" as a name ?

Obviously it would work either way; this mainly reflects historical
usage.  "obs_title" is more consistent.  These field names are very
similar to FITS keywords where "TITLE" is already used (which is
the main reason we are using this name at all).  Finally in current
usage there is a subtle distinction between "title" and "description".
"title" is supposed to be short, less than one line, and is used to
generate the title for plots and such (hence the name).  "description"
can be longer, e.g. a paragraph, giving a more complete description of
the object, such as might be displayed in a popup.  In practice people
are more likely to provide "title" than the longer "description".

 	- Doug