Cal Bench Alignment

Notes on aligning the cal bench:

Measure the Positions of the Light Sources and Fibers

Use the cal bench FVC and take images of the various calibration sources. Use the ND filter wheels and exposure time to get reasonable exposures and check if all the sources fall on to the same pixel position.

Then with cal sources off, turn on the science back illumination LED, adjust the exposure time to get a good position measurement. This indicates where the science fiber is. Repeat for the sky fiber. They should be aligned to one another.

It is challenging to get back illumination in to the simulcal fiber as there is no built in LED. It is possible to open the calibration scrambler and shine a light in there, but it should be done carefully. If you can get illumination in to the cal fiber, its position can be measure in the same way.

The goal is to get all of these to fall on the same pixels.