SISPI support for Calibration Procedures

SISPI will play a role not only during standard survey operation but must also provide the observer with the tools (controls) to take a variety of calibration frames. To better understand these requirements Kyler and I met with Darren to discuss typical calibration procedures and how they might be used for DES.
Typically there is a hierarchy of nightly, weekly and monthly procedures. Some of the details (for DES) are still in flux and will be better defined as we continue to develop our calibration system.

Nightly calibration procedures include dome flats, dark and bias frames. For dome flats we will take several exposures with all filters. Lights-On, lights-off flats will be useful to subtract stray light.
Dark frames are taken with the shutter closed and bias frames are taken with 0 second exposure time. We means we read out the CCDs immediately after the reset signal.

We expect to visit standard star fields to get an illumination correction. If not nightly we'll do this at least for every photometric night.

Twilight flats are another possibility.

Every week we will check the quantum efficiency of the system using calibrated light sources and photodiodes on the focal plane (maybe paired with the 2kx2k CCDs)

Every month we will perform a full spectrophotometric calibration in which we scan through the entire spectrum (maybe from 300 -1100 nm) and illuminate the entire focal plane to give us the QE of every pixel.