Two optical payloads on the GF-5 satellite have produced by Beijing Institute of Space Mechanics and Electricity. The full-spectrum spectral camera has the characteristics of wide spectral range, high spatial resolution and high accuracy of radiation calibration. It has reached the domestic leading and international advanced technology level, which has greatly improved China's high-precision observation capability. This paper designs a video circuit for the visible near-infrared spectrum of the camera. The circuit implements timing control and driving of the detector, as well as analog to digital conversion and processing of the analog signal. It completes the acquisition of 8 channels of analog signals, and outputs 14 bits of quantized bits and 30 Mbps of single channel data. The system achieves high signal-to-noise ratio (SNR) through high-stability power supply, high-speed drive level shifting and high-precision (2ns/step) timing control. Under the given simulation test conditions in the laboratory, the measured signal-to-noise ratio of the visible light channel reached 307, and good image data was obtained in the external scene imaging and in the space.
|