Research On Key Technology Of High Precision Pulsed Laser Ranging

Pulsed laser ranging has been widely used in the fields of space rendezvous and docking,satellite navigation,radar,communication,topography and so on,which has many merits such as far distance measurement,high precision of ranging and good directivity.In this thesis,the cause of the ranging error was analyzed and the model of the ranging error was established.The pulsed laser drive circuit was designed to reduce the pulse width of the pulsed laser signal and increase the laser drive current,The output pulse width can reach 8ns and the output current can reach 20 A under the condition of the load resistance 1? supply voltage 60V;According to the variation characteristics of the echo signal amplitude,a controllable gain amplifier circuit was designed to effectively control the amplitude variation of the echo signal and reduce the drift error of the received power;Through the theoretical modeling and analysis,the constant fraction discrimination circuit was designed to reduce the drift error of the identify point of time;In the aspect of system control,communication and signal processing,the core processing unit based on FPGA was designed,and the measurement frequency of the system was improved by nesting among the multi-layer state machines.The system through the FPGA as a core to control and configure time interval measurement unit,the system's ranging accuracy of 30 cm,measuring range reached 1500 m.A large number of measurement experiments in the measurement interval have been carried out on the calibrated distance.The measurement accuracy of the system is verified and the influence of the internal noise source on the measurement results was analyzed.Finally,the linearity of the system within the whole measurement interval was verified by multiple measurements at different distances.