Digital Laser Drive Circuit And Digital Signal Processing Technology In Ladar

Digital processing the signal/information of the ladar and laser ranging is theimportant direction in the development of ladar and laser ranging. It has greatsignificance for ladar and laser ranging system to improve the accuracy, reliability,achieving control and processing information in computer. This dissertation mainlydiscusses a digital nanosecond pulsed power supply for laser ranging system and thedigital signal processing technique of echo signal in ladar.1, The digital power supply which produces nanosecond pulse by digital logicoperations for seed laser is mainly composed by Field Programmable Gate Arrays(FPGA), accurate delaying chips and laser diode driver. The repetition rate and pulsewidth of the laser pulse can be gradually adjusted from1to10kHz and2to18ns,respectively. The pulse peak can be continuously adjusted from0-4V and thethreshold current from100-500mA. Furthermore, the time of rising and falling edgesfor the laser pulse is less than2ns.2, Digital fast high-precision measurement theory and technique of phase-shiftlaser ranger finder is researched. The method is based on the combination ofunder-sampling technique, digital down converter and digital synchronous detectiontechnique and having the characteristics of high accuracy, high speed and high signalto noise ratio. Simulation results show that the ranging error is about0.94mm. Theresults demonstrate the feasibility of this method and provide an important referencefor further study.