Method and device for determining target radiation brightness characteristic under outdoor visible light condition

The invention relates to a method and a device for determining target radiation brightness characteristics under an outdoor visible light condition. The method comprises the following steps: determining multiple test conditions; for each test point in the preset range, performing downward-looking detection on the tested target by using a pre-calibrated imaging brightness meter to obtain an image at each test point under the current test condition and a gray value of each pixel in the image; the conversion relation between the gray value of each pixel on the detector of the imaging brightness meter and the visible light radiation brightness value is known; determining a radiation brightness value of each pixel in each test point image based on the conversion relation; determining a radiation brightness difference value of different areas in the corresponding image based on the radiation brightness value of each pixel; and analyzing the change rule of the radiance difference value of different areas under each