Method for correcting nonuniformity of space camera on-orbit radiation response

Abstract

The invention discloses a method for correcting the nonuniformity of space camera on-orbit radiation response, belongs to the technical field of space camera on-orbit image processing, solves the problems that an ideal effect is difficult to achieve during correction, and the cost is high, and improves the real-time performance of interpretation. The method is characterized in that a two-point calibration correction method is adopted; dark field gray value points and subsaturated gray value points are selected; pixels have the same gray value after images are corrected under the condition that light is uniformly transmitted; the gray value of each pixel is equal to zero basically after the image are corrected under the condition of a dark field; and images are subjected to a minus operation and a multiplication operation sequentially, operation results are subjected to upper limit judgment, and the space camera on-orbit radiation response nonuniformity correction method is implemented. According to the nonuniformity correction method, a function of correcting the nonuniformity of the space camera radiation response is realized by the field programmable gate array (FPGA) software design of a space camera imaging controller; a few restriction is provided for modification of FPGA software, so that the flexibility of implementing correction is improved, and a good correction effect can be obtained; and downlink images can be directly interpreted, so that the real-time performance of space camera image interpretation is improved.

Description

technical field [0001] The invention belongs to the technical field of on-orbit image processing of a space camera, in particular to a method for correcting non-uniformity of radiation response of a space camera on-orbit. Background technique [0002] The space camera imaging system is mainly composed of six parts: imaging controller, timing driver, detector (TDI-CCD), optical-mechanical system, pre-amplification circuit and video signal processing circuit. Its structure is as figure 1 shown. [0003] The imaging controller adopts the FPGA chip of Xilinx company model XQ2VP40, which mainly completes the functions of TDI-CCD timing signal generation and image data packaging. The chip integrates 192 BlockRam resources with a capacity of 18Kbit, which can be configured as RAM, ROM or FIFO by calling the IP core to realize the function of data storage. [0004] The detector adopts the visible light TDI-CCD customized by Dalsa Company, which consists of 4096 pixels in the hori...

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Problems solved by technology

[0007] In order to solve the problems existing in the prior art, the present invention provides a method for correcting the inhomogeneity of the radiation response of the space camera on orbit. This method solves the problems of difficult correction and high cost. At the same time, the problem of real-time interpretation is also obtained. improved

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