To improve the tracking performance of an orbital target-tracking system, this paper researches the limited magnitude calculation method and photoelectric detection performance in a photoelectric tracking system, and deduces and sets up the calculation model of the limited magnitude of the orbital photoelectric tracking system based on the characteristics of target luminance, background luminance, and CCD noise; it analyzes key factors that affect its photoelectric detection performance; discusses the relation of the limited detectable magnitude of the photoelectric detection system with the exposure time of the CCD, the threshold of the signal-to-noise ratio, and the dark current of the photoelectric detection system; and gives the calculation function and the change curve of corresponding function parameters. Through a synchronous tracking experiment, the detection performance and limited magnitude calculation function of the target photoelectric tracking system were verified, and the results show that within a certain illumination, the longer the exposure time of the CCD, the smaller the dark current of the photoelectric detection system. The test data are in accordance with the theoretical calculation data.

This paper researches the calculation method of space target optical characteristics to improve performance and sensitivity of the photoelectric detection target. In accordance with the detection principle of the photoelectric detection target and the detection screen thickness geometrical relationship, this paper sets up the space target spectral characteristic model using the surface element mesh analysis method and the bidirectional reflection distribution function. It provides the incident radiation energy calculation function in the optical lens entrance pupil of the photoelectric detection target detection area in order to determine the total spectral radiance intensity calculation function of the space target. The paper also reports on the minimum flux calculation function detected by the photoelectric detection target based on the definition of detection sensitivity and the change curve of the target’s radiation energy when entering the detection area at different incident angles. Lastly, it demonstrates the spectral illuminations of an optical detection system under different radiation wavelengths and reflection radiation angles, as well as change curves of the target’s spectral radiation intensity passing through the detection screen area and at different incident angles from the same distance.

This article develops a new sensor that can detect projectiles in all-weather with high sensitivity and a large field of view. Two high-power line lasers are used to design an active photoelectric detection sensor with a fan-shaped detection plane. The size of the designed fan-shaped photoelectric detection receiving plane is the same as the luminous fan-shaped plane light source to make the two fan-shaped planes coincide with each other, forming an active detection screen. Based on the principle of active photoelectric detection sensor, a linear array photoelectric detector is selected, in which multiple unit p-i-n detectors are spliced together, and an amplifier processing circuit with low noise and high sensitivity is designed. Combined with the geometric structural features of the active detection screen, the radiation characteristics calculation model of the projectile in a fan-shaped detection plane is developed using a five-parameters bidirectional reflectance distribution function (BRDF). Finally, the total radiation intensity calculation function of the projectile’s surface is derived considering the influence of environmental factors and the output signal and signal-to-noise ratio (SNR) model of the active photoelectric detection sensor is set up. Comparative experiments under different environmental illuminations verify that the detection ability has been significantly improved in active photoelectric detection sensors.