A simple test Camera
There is one ccd with name "0"
It has four amplifiers with names "00", "01", "10", and "11"
The camera is modeled after a small portion of the LSST sim Summer 2012 camera:
a single detector with four amplifiers, consisting of
raft 2,2 sensor 0,0, half of channels 0,0 0,1 1,0 and 1,1 (the half closest to the Y centerline)
Note that the Summer 2012 camera has one very weird feature: the bias region
(rawHOverscanBbox) is actually a prescan (appears before the data pixels).
A raw image has the sky in the same orientation on all amplifier subregions,
so no amplifier subregions need their pixels to be flipped.
Standard keys are:
amp: amplifier number: one of 00, 01, 10, 11
ccd: ccd number: always 0
visit: exposure number; test data includes one exposure with visit=1