Flatfields
Below are a bunch of views of the engineering grade
of the Rockwell chip under serveral different conditions.
Warm
When the chip is a room temperature it is similar to being
in a fully saturated condition.
The mean value is around 11235 DN.
The differential bias offset of the four quadrants is
visible.
The vertical bands have an amplitude of about 20DN and a period
of 40 pixels (~630Hz).
They have an unknown origin and subtract out.
Below is a rowcut.
Reset
Below is an image of the chip taken cold (92K)
with a very short exposure time that looks like a purely
reset chip.
It has a mean of 33203 DN.
Sky
Below is a sky flat taken with a mean signal of 5800 DN
The picture is shown at low contrast to show the
relative flatness of the chip.
Below is a rowcut thru the above sky image.
And a histogram of the distribution.
Last updated on 2000 September 15