PhoSim Tutorial 9: How to Generate Calibration Data

Calibration data can be generated in a similar manner as with a real telescope. Basically, the commands have to be given to the 

A bias frame can be generated with the catalog:

phosim examples/bias

The catalog simply has these two commands to set the exposure time to 0 and to make the minimum number of sources to be 0. This is necessary because PhoSim will not generate chips with no sources on them by default.

vistime 0.0

minsource 0

The electron image will be empty, and the amplifier images will have the appropriate bias level and read noise. 

Similarly, a dark can be generated by closing the dome and setting the exposure time to a reasonably long value. An example of this is the following command.

phosim examples/dark

The example has the following commands that set the exposure time to 5 minutes, have the minimum source as 0, and close the dome with "telconfig 1".

vistime 300.0

minsource 0

telconfig 1

The electron image will contain dark current (if significant in the device) and many cosmic rays since the exposure time is 300 seconds. The example above produces this image:

Similarly, a flat can be generated by simulating an illumination pattern across the field. This can be done with this example that uses a flat SED illumination pattern.

phosim examples/flat

This catalog will close the dome and put on the dome light (telconfig 2). The dome light will have an intensity of 20.0 magnitudes per sq. arcsecond and a flat spectrum (domewav 0). If the dome wavelength is set to any other value other than 0, it simulates a monochromatic flat (i.e. laser illuminated). The commands are below.

vistime 15.0

telconfig 2

minsource 0

domeint 20.0

domewav 0

The flat image in this example is shown below