Method for carrying out relative radiometric calibration on CCD (Charge-Coupled Device) image

Abstract

The invention provides a method for carrying out relative radiometric calibration on a CCD (Charge Coupled Device) image, which is used for carrying out relative radiometric calibration on an original image obtained through push broom of a one-dimensional CCD camera. The method comprises the following steps of step A testing radiometric calibration data (formula) of each detection unit of the one-dimensional CCD camera under different integrating sphere output radiances Lj and different integral times Tk by utilizing an integrating sphere method; step B computing a relative radiometric calibration coefficient of each detection unit by the radiometric calibration data (formula) of each detection unit of the one-dimensional CCD camera under different energy levels Lj and different integral times Tk through an improved relative radiometric calibration model through; and step C carrying out radiation intensity calibration on each pixel in the original image by utilizing the relative radiometric calibration coefficient of each detection unit corresponding to a pixel so as to obtain an image after relative radiometric calibration. According to the method, the problem of obvious chromatic aberration of a splicing image of the interior of the same flight strip and an adjacent flight strip, which is caused by the difference between the integral times during processing of an airway array CCD image, is avoided.

Description

technical field [0001] The invention relates to the field of remote sensing technology, in particular to a method for performing relative radiation correction on a CCD image. Background technique [0002] One of the core components of the aviation optical linear array load is the CCD (Charge-coupled Device, charge-coupled device) array, which contains many detection units. Due to the limitation of the manufacturing process, the parameters of each detection unit cannot be guaranteed to be the same, resulting in a certain difference in the response characteristics of each detection unit of the CCD array. For the push-broom sensor, the remote sensing image is pushed through the linear CCD array. Due to the difference in the response characteristics of each detection unit of the CCD array, the final image will have uneven brightness in the entire field of view, or even Exhibits banding noise. [0003] The radiometric correction of optical remote sensing images includes relativ...

AI Technical Summary

Problems solved by technology

Even under the same incident radiation conditions, the DN value output by the CCD camera will be different due to the difference in the integration time of the CCD camera

If the relative radiation correction method shown in Figure 1 is still used to perform radiation correction on the aero-optical linear array load image, the DN values ​​of the images acquired at different integration times after relative radiation correction will not be on the same benchmark, which makes the use of There will be obvious chromatic aberration when the corrected adjacent air strip images are stitched together, which will affect the stitching effect

At the same time, due to the dynamic change of the integration time, the images of the same ground object scene in the adjacent flight zone have different DN value outputs, so that it is impossible to use the unified absolute radiometric calibration coefficient to perform absolute radiometric correction on the image, which will give the subsequent absolute radiometric correction band come with great difficulty

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