Gain Drift

The AddGainDrift task, part of the ExoSim simulation package, is designed to model and apply gain drift to a detector simulator. The gain drift is constructed as a polynomial trend dependent on time and wavelength.

The polynomial coefficients are randomly generated within specified ranges. Finally, the resulting amplitude is rescaled according to the input parameters.

Usage and Parameters

To apply gain drift using the AddGainDrift task, the following parameters should be specified in the configuration file. Here we include also some example values. - gain_coeff_order_t: Order of the polynomial used for the time-dependent trend. - gain_coeff_t_min and gain_coeff_t_max: Minimum and maximum values for the randomly generated coefficients of the time-dependent polynomial trend. - gain_coeff_order_w: Order of the polynomial used for the wavelength-dependent trend. - gain_coeff_w_min and gain_coeff_w_max: Minimum and maximum values for the randomly generated coefficients of the wavelength-dependent polynomial trend. - gain_drift_amplitude: gain drift desired maximum amplitude relative to the signal.

These parameters control the characteristics of the gain noise, allowing for detailed modeling of the detector’s response.

<channel>
    <detector>
        <gain_drift> True </gain_drift>
        <gain_drift_task> AddGainDrift </gain_drift_task>

        <gain_drift_amplitude> 1e-2 </gain_drift_amplitude>

        <gain_coeff_order_t> 5 </gain_coeff_order_t>
        <gain_coeff_t_min> -1.0 </gain_coeff_t_min>
        <gain_coeff_t_max> 1.0 </gain_coeff_t_max>

        <gain_coeff_order_w> 5 </gain_coeff_order_w>
        <gain_coeff_w_min> -1.0 </gain_coeff_w_min>
        <gain_coeff_w_max> 1.0 </gain_coeff_w_max>
    </detector>
</channel>

Alternatively, the AddGainDrift task can also randomly estimate the amplitude of the gain drift by using the range defined with the keywords: gain_drift_amplitude_range_min, gain_drift_amplitude_range_max:

<channel>
    <detector>
        <gain_drift> True </gain_drift>
        <gain_drift_task> AddGainDrift </gain_drift_task>

        <gain_drift_amplitude_range_min> 1e-2 </gain_drift_amplitude_range_min>
        <gain_drift_amplitude_range_max> 5e-2 </gain_drift_amplitude_range_max>
    </detector>
</channel>

Customization

The AddGainDrift task is designed for flexibility and can be customized or replaced by a user-defined implementation as needed.

Note

Users are encouraged to develop their own custom realizations of this task to fit specific simulation requirements (see Custom Tasks).