[Obscore1.1] WD comments

[Douglas Tody]

On Wed, 24 Jun 2015, CresitelloDittmar, Mark wrote:
> pg 25: Axes dimensions
>  Outside of the pixelated image context, what values do these hold?
>  For example, the sparse cube (ie: event list).  do each of these hold
>  the #events? or are s_dim1,s_dim2 ==  the span along that axis? and
>  if so, in what frame?
>  It seems that #events is closest to the description as the number of
> samples.

For event data which is not imaged, such as an event list, probably the
best one can do is have t_dim specify the number of events.  The spatial
coverage would be specified with s_fov and the spectral coverage with
em_min/max.  The binning on the spatial and spectral axes is meaningless
and should be zero.  If a precomputed image for the observation is also
provided, that would have all the dim values and would share the same
obs_id.

 	- Doug