Development of low light level and wide dynamic range visible nephogram imaging technology

摘要

The novel visible nephogram imaging technology for polar orbit platform is demonstrated in the paper, and it could be operated in from quarter moon to noon sunlight. The critical technologies and theirs solutions of the novel nephograph are included: (ⅰ) the low light level imaging capability is achieved by the combination of time delay and integration charge coupled device (TDI CCD) with push-broom imaging method; (ⅱ) the large field of view capability is implemented by the combination of 3 pieces of imaging module with smaller field of view; (ⅲ) the wide dynamic range capability is achieved by the combination of TDI CCD with gradient neutral density filter (NDF). On the basis of the analysis and trade-off of system design, the prototype of novel visible nephograph for polar orbit platform is developed. The results of experiments and tests in ground demonstration are satisfying, and the nephograph prototype is mainly met the customer demand. In the end of paper, several problems and theirs solution of novel technology for space application are also mentioned.