Image Processing Fundamentals - On-chip Electronic Noise

On-chip Electronic Noise

This noise originates in the process of reading the signal from the sensor, in this case through the field effect transistor (FET) of a CCD chip. The general form of the power spectral density of readout noise is:

Readout noise -

where a and are constants and is the (radial) frequency at which the signal is transferred from the CCD chip to the "outside world." At very low readout rates ( < _min) the noise has a 1/ character. Readout noise can be reduced to manageable levels by appropriate readout rates and proper electronics. At very low signal levels (see eq. ), however, readout noise can still become a significant component in the overall SNR .