A Gating System Based on FPGA for Data Acquisition of Doppler Wind Lidar

摘要

The contribution of this paper is proposing a gating system to exclude bad data for data acquisition of Doppler Wind Lidar (DWL). In the field of DWL, the seed light injection technology is applied to get high-power single longitudinal mode laser. Nevertheless unsuccessful seed injection will introduce spoiled points. Comparing to the case without seed injection, the set up time of outgoing laser is about 2ns smaller in the case with successful seed injection. The gating system consists of a photoelectric detector and gating module which is used to measures the delay so as to identify whether the seed injection is successful in real time and outputs a pulse to trigger data acquisition system (DAQ) with successful injection. In order to get enough timing accuracy, a field programmable gate array (FPGA) built-in Time-to-Digital Converter (TDC) with RMS of 181ps is used. The test has been done to verify the performance of the gating system. Result shows that the confidence probability of distinguishing the successful and unsuccessful seed injection can approximately reach 99.9%.