Re: ATM All Sky Instrument

[Richard Schwartz <richas@idt.net>]

A CCD all sky survey camera offers some interesting possibilities.  

Chemical photography suffers from a defect called RECIPROCITY FAILURE. 
This means that there is a minimum threshold below which photons are not
recorded.  The consequences of this problem are that cameras using
chemical photography are build as fast as possible.  This leads to
complicated schemes for controlling abberations.

However, if CCD's do not suffer reciprocity failure, there is no need
for a fast optical system and the design can be a lot simpler.

The big problem with CCD's is that they are tiny.  They have a small
area, so will cover only a small area of the sky, unless the focal
length is short.  This tends to drive the camera design to a smaller
size.  What we need is a 5" x 5" CCD.