Demonstration of coherent differential absorption lidar for wind and water vapor measurements using high-precision wavelength stabilization circuit

We have developed a differential absorption lidar (DIAL) that simultaneously measures water vapor and wind for heavy rain forecasting. In this paper, we summarize the development of a wavelength control unit that takes environmental resistance into consideration and the demonstration results of water vapor and wind lidar. Temperature tests of the wavelength stabilization circuit were conducted, and it is confirmed that the circuit was stable within 0 - 60°C with a frequency stability of ±10MHz and verify the performance of the DIAL with the prototype wavelength stabilization circuit. The DIAL was installed outdoors to measure water vapor in the vertical path. As a result of comparison with radiosonde measured in the same area, we confirmed that the accuracy was equivalent to the target measurement accuracy (2 g/m3 or less).