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Camera for the Large Scale of the Solar Surface
Francis
Beigbeder, Sylvain Rondi, Nadège Meunier, Michel
Rieutord Thierry Roudier, Guy Delaigue, Laurent
Pares, René Dorignac.
Observatoire Midi-Pyrénées,
Laboratoire dAstrophysique
Scientific Detectors Workshop 2005 Taormina,
Italy
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CALAS is an instrument whose purpose is to
observe a large field of view with a very large
resolution and a good temporal cadence. The main
objective is the study of super-granulation. It
will be installed at the Lunette Jean Rösch (a 50
cm diameter refractor) at the Pic du Midi
Observatory. The instrument will present two
optical paths in parallel, one for simple imaging
and the second with a magneto-optical-filter
(MOF) for magneto-graphic observations.
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DETECTOR
Fillfactory IBIS16000
16 Mpixel CMOS Image Sensor It has a pixel size
of 12 x 12 µm2, and on chip Double Sampling
correction circuitry to remove the Fixed Pattern
Noise caused by non-uniformities in threshold
voltages of the readout electronics. The sensor
is read out of through four parallel analog
ouputs, 4 x 10 MHz 2,5
frame/second
3950 x 4090 pixels QE x FF 40 Full Well
240 ke Noise 35 e 64801 (76 dB)
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CONTROLLER
To handle the CMOS sensors we have kept the
timing board of a classical ARC GenII controller,
but associated with customized analog, clock and
interface boards. This special architecture
allows us to link in parallel (LVDS) the
ADCs outputs to the Acquisition System. The DSP
code allows to read the detector with global or
curtain shutter and windowing.
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ACQUISITION SYSTEM
The acquisition System is build with a PC under
Windows XP equipped with a CORECO X64-LVDS PCI-X
frame grabber, a 64 bit image acquisition board
for parallel output, digital cameras. It allows
image transfer to host memory at 528 MB/s Used
here with four 14 bits taps configuration. We
plan to have a Network Attached Storage (NAS) of
several Tera Bytes capacity to save a run of 2 or
3 days of observation.