[Nexus] NXsas with multi-frame image set

[Pete R Jemian]

I want to store a set of images according to the NXsas application 
definition.  In the current case, these images form a time series. 
NXsas defines /entry/instrument/detector/data as a 2-D image frame.

What's my storage strategy?  Any of these or something different?

first choice: 3-D frame set
     /entry/instrument/detector/data: (frames, rows, columns)

second choice: single frames in same NXdetector
     /entry/instrument/detector/data_frame_1: (rows, columns)
     ...
     /entry/instrument/detector/data_frame_n: (rows, columns)

third choice: one group for each frame
     /entry_frame_1/instrument/detector/data: (rows, columns)
     ...
     /entry_frame_n/instrument/detector/data: (rows, columns)
     and link other objects (NXsample, ...) from /entry_frame_1/*

Pete