Optical remote sensors in the 21st century

The current status of optical remote sensors is briefly surveyed, and shortcomings of those in use nowadays are discussed. Development trends of future sensors are predicted. Because increasing the spatial and spectral resolution weakens the signals the detector receives and then decreases the SNR, the SNR has to be increased in order to develop high-resolution optical remote sensors. Two possible methods to solve this problem are discussed. One is to install a scan mirror near the entrance pupil of the optical remote sensor; the other is to fix a rotating multiple-side prism near the entrance pupil of the optical remote sensor. The dwell time of the detectors is extended, the moving blur is lessened, and the SNR increases. A method of real-time-data processing with an optical computer is proposed.