A pulsed laser spot tracker and spot tracking method

Abstract

The invention discloses a pulse laser spot tracker and a spot tracking method. The tracker includes an optical aiming unit, a four-quadrant photodetector, an acquisition processing circuit and an image display unit. After the optical aiming unit is incident on the four-quadrant photodetector, the acquisition and processing circuit collects and processes the output electrical signal of the four-quadrant photodetector, and then displays the coordinates of the center of mass of the spot on the image display unit in real time; the laser outputs a repetitive frequency pulse laser ; The spot tracker of the present invention first carries out the acquisition processing of the whole period to the first few pulses of the irradiation laser, calculates the arrival time and pulse width of the follow-up pulse, and uses it for the synchronous triggering of the follow-up four-quadrant detector, ensuring Subsequent light pulses are only collected within effective light pulses, which meets the requirements of spot tracking under the influence of light pulse parameters when the atmosphere changes.

Description

technical field [0001] The invention belongs to the technical field of laser tracking, and particularly relates to a pulsed laser spot tracker composed of a four-quadrant detector. Background technique [0002] Laser trackers use the collimation and high-speed transmission characteristics of light to accurately capture and track moving objects in free space. The principle of spot tracking is to use a laser to indicate the target, and then the spot tracker performs precise angle measurement and tracking on the target by receiving the light reflected by the target. Laser trackers are widely used in the measurement and docking between satellites, atmospheric laser communication and military fields. In laser semi-active guided weapons, laser spot trackers are usually installed on helicopters or fixed-wing aircraft to accurately track the laser spots irradiated on the target and guide the weapons to strike. It provides targets for both guided and unguided weapons. The visual sy...

AI Technical Summary

Problems solved by technology

[0003] In practical applications, the laser spot tracker needs to track and capture the spot reflected by the repetitive pulse laser, but it is affected by the atmospheric turbulence and the change of the refractive index, which causes the spot incident to the tracker to fluctuate with the atmosphere, so it needs to be accurate Only by measuring the changing characteristics of the light spot over time can the combatants be provided with accurate launch guidance information

[0004] At present, the core of the design of the laser spot tracker is to collect the laser peak signal output by the four-quadrant photodetector, such as "an optical precision tracking detector based on a double four-quadrant detector (Chinese patent 200910093364.8)" and "a laser spot And echo tracking monitoring device (Chinese patent 201811336974.1)", the signal collected and captured is a solid-state laser pulse signal with a pulse width of 10-20ns and a repetition rate of 10-20Hz. At present, the methods of pulsed laser spot detection based on photodetectors mainly include There are two methods of peak hold and high-speed acquisition. The peak hold is to widen the nanosecond pulse signal incident on the detector to the microsecond level, and then use low-speed data acquisition for acquisition. The problem is that this widening is based on the peak intensity of the pulse. Widening reduces the difficulty of data acquisition, but it cannot guarantee the linearity and dynamic range of data acquisition, and cannot reflect the real parameters of the laser spot

In comparison, high-speed acquisition is an accurate solution, but for 10ns pulse signals, the ADC sampling rate of the sampling system needs to reach 1GS / s or more, and the data storage and real-time The display brings difficulties, which ultimately affects the accuracy and real-time performance of spot tracking

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