`showapi.calibration`

¶

This module describes the calibrations applied to the SHOW instrument.

## Readout Noise¶

The raw readout signal coming off the SHOW detector is given by

where \(D_{meas}\) is the measured signal in digital numbers (DN), \(B\) is a DC bias, \(D_{dark}\) is the dark current signal and \(D_{light}\) is the signal due to light incident upon the detector pixel. This can be re-arranged to give the signal due to light.

and the error analysis is given by,

### Measurement Error¶

For convenience we can write,

where \(D_{actual}\) is the total signal in digital numbers (DN) related to the number of electrons stored in the pixel, alternatively

where \(N_e\) is the total number of electrons in the the pixel and \(G_e\) is the number of electrons per DN. The error in the number of electrons is given by Poisson counting statistics,

and this can be converted to equivalent digital noise error as

which can be manipulated to give