Space Camera Imaging Gain In-Orbit Adjusting Strategy

A Multi-Step Gain Adjusting Strategy (MSGAS) of space camera was proposed, which was used to get higher SNR (Signal-Noise Rate) image. When the space camera working in poor light condition, the CCD signal was so weak that it´s difficult to get a clear image, to reduce the quantization noise and improve the SNR, we must amplify the CCD signal first and then quantize. The MSGAS was achieved by adjusting the gain of the CCD (Charge Couple Device) signal processor step by step, the upper limit and lower limit were set, if the MDN (Mean Digital Number) of a fixed length image data was not between the lower and upper limit, the gain was adjusted step by step. In the experiment, the upper limit, lower limit and the step were set, and the result of the experiment showed that MSGAS was robust and SNR was improved from 28 to 39.