Saturation time

The saturation time is estimated in each channel by SaturationChannel. This Task sums the source and the foreground focal plane and look for the maximum and minimum signals. From the detector details, it then estimates the saturation time. The channel description must include the well depth and the fraction of well depth to use:

<channel> channel_name

    <detector>
        <well_depth> 100000 </well_depth>
        <f_well_depth> 0.9 </f_well_depth>
    </detector>

</channel>

The saturation time is estimated as the well depth divided by the maximum signal in a pixel of the array. Then the integration time is the saturation time multiplied by the fraction of the well depth to use.

Inside RadiometricModel this tasks is handled by the compute_saturation method. To use the default task in a script on a channel the user can write:

import exosim.tasks.radiometric as radiometric

saturationChannel = radiometric.SaturationChannel()
sat, t_int, max_sig, min_sign = saturationChannel(table=table,
                                                  description=description
                                                  input_file=input)

Where table is the wavelength radiometric table with aperture, ch_name is the channel name, description is the dictionary containing the channel information from the xml file, and input_file is the input hdf5 file containing the focal planes.