High-resolution optical push-broom satellite steady-state reimaging sensor calibration method and system

Abstract

The invention provides a high-resolution optical push-broom satellite steady-state reimaging sensor calibration method and system; the calibration method includes the steps of building a single TDI CCD unsteady-state strict geometric model and a virtual CCD steady-state imaging strict geometric model, acquiring a rational function model according to the virtual CCD steady-state imaging strict geometric model, establishing a one-to-one mapping relationship between single TDI CCD images and virtual CCD reimaged images, and generating an image after the sensor is calibrated according to the original single TDI CCD images. According to the calibration method and system, the virtual CCD imaging principle is combined, the positioning consistency of a multiple TDI CCD unsteady-state geometric model and a virtual single-line-array CCD steady-state geometric model is utilized, image distortion caused by platform tremble is calibrated while seamless splicing of multiple CCD images is realized, standard scenery images and corresponding high-precision RPC parameters are provided for users, and subsequent image application is facilitated.

Description

technical field [0001] The invention belongs to the technical field of remote sensing satellite data processing. More precisely, the invention is a sensor correction technical solution for steady-state re-imaging of high-resolution optical push-broom satellite images adopted in the ground data processing process of remote sensing satellites. Background technique [0002] With the gradual improvement of spatial resolution, the camera structure of high-resolution optical satellites becomes extremely complex. High resolution generally means that the spatial resolution is better than 5 meters. In order to ensure the imaging quality and imaging efficiency, the photosensitive element is updated from the traditional single-integration CCD (charge-coupled device) to multiple-integration TDICCD (time-delay integration CCD). Expand from a single push-broom line array to multiple spliced ​​push-broom line arrays; at the same time, the improvement of spatial resolution also makes the ph...

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Problems solved by technology

[0004] At present, most of the sensor calibration methods only consider the camera design to solve the splicing problem due to the multi-chip TDICCD, and do not consider the stability of the satellite during the push-broom process; for the problems of fragmentation speed and integration time jump, usually the sampling line frequency Normalized image resampling can easily lead to over-resampled images and reduce image quality

On the other hand, when the satellite trembles, it is difficult to directly generate high-precision RPCs (RFM polynomial coefficients) due to the jitter of the attitude, and only a strict geometric imaging model can be used, which reduces the efficiency of data application

Therefore, the traditional sensor correction method has been unable to meet the high-precision geometric processing requirements of high-resolution remote sensing optical satellites

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