Abstract: Aiming at the problems of limited acquisition method, band registration, and data quantification of near-surface multispectral images, this paper introduces a self-developed filter wheel multispectral camera that can work continuously in the field, has simple operation and easy band registration, and completes relative radiometric correction and absolute radiometric calibration with high-precision integrating sphere in the laboratory. The multi-stage brightness calibration method and empirical linear method are used to establish a calibration model to correct the uneven response of multi-band multispectral camera and calculate the spectral radiation brightness at the pupil. In this paper, we design data acquisition and processing experiments of different brightness and integration time, and give the optimal integration time range for each band of the new camera. The results of radiometric correction and calibration show that the selected correction coefficient has high stability and reliability for multispectral images under different imaging conditions, and is suitable for radiometric correction of filter wheel-type multispectral cameras. The calibration results can be used to quantitatively retrieve the target parameters of the land surface, which has broad application prospects in the fields of crop monitoring, environmental monitoring and protection.

Key words: filter wheel type, multispectral imagery, radiometric calibration, calibration method