Quantum efficiency variation map#

The QuantumEfficiencyMap tool allows the creation of quantum efficiency variation maps that can be used in ExoSim`(see :ref:`qe_map).

The tool assumes that the QE has a normal distribution around the median (which is given by the Estimate responsivity) and it requires the standard deviation as input. Then it randomises the pixel QE according to the indicated distribution.

The following configuration are to be set into the tool input parameters

<channel> channel_name
    <detector>
        <qe_sigma> 0.1 </qe_sigma>
    </detector>
</channel>

Then the tool can be run as

import exosim.tools as tools

tools.QuantumEfficiencyMap(options_file='tools_input_example.xml',
                           output='output_qe_map.h5')

The result will be like

../../_images/qe_map_phot.png ../../_images/qe_map_spec.png

and then applied as

../../_images/qe_map.png

with the QE normalisation distributed as

../../_images/qe_variation_histo.png

The default QuantumEfficiencyMap also allow for QE degradation. Given the the amplitude of the degradation an the time scale, it creates a randomised aging factor for each pixel and interpolate the QE efficiency map in time to age accordingly.

<channel> channel_name
    <detector>
        <qe_sigma> 0.1 </qe_sigma>
        <qe_aging_factor> 0.01 </qe_aging_factor>
        <qe_aging_time_scale unit="hr"> 5 </qe_aging_time_scale>
    </detector>
</channel>
../../_images/qe_aging_histo.png

The resulting QE at 5 hr will be the product between the QE map computed with <qe_sigma> 0.1 </qe_sigma> and the aged map.