Research Of The Flight Experiment Of Micro-pulse Lidar (MPL)

MPL (Micro-pulse lidar) is an effective method to study optical property of aerosol and it is significant for active remote sensing of atmosphere aerosol using MPL aboard the aircraft. The airborne micro-pulse lidar system and its flight experiments are discussed in this paper, including four parts:In the first part, the advantage of micro-pulse lidar over traditional ones and research progress home and abroad are firstly introduced. The technology of ground-based MPL is mature, but the experiments and correlative literatures of airborne are seldom. Then the developments of other traditional airborne lidar are introduced.In the second part, the interaction of laser and atmosphere and the working theory of airborne micro-pulse lidar are introduced at first. Based on these theories and the former MPL system in our group, the hardware design of micro-pulse lidar is carried out. The key of airborne MPL hardware system is to establish a modularized frame with shock absorption function. The frame meets the requirements conditions of weight, size and power consumption, and has the ability of anti-strike and anti-shock.In the third part, the data processing method of airborne micro-pulse lidar is studied. Firstly, the detecting data of airborne micro-pulse lidar is sorted and calibrated. Then the extinction coefficient of aerosol is inversed using Fenald method from the measurements of airborne micro-pulse signal. In this process, the new problem of ground-to-sky detection to sky-to-ground detection is that the airborne lidar can't select the same calibration spot as the ground-based system because of aviation height. The method of inverse analysis and the method of combination of forward integration and backward integration are applied to solve this problem, Then the errors of inversion are analyzed. At last, the values of AOD (aerosol optical depth) measured respectively from airborne MPL and MODIS are compared and the pertinence analysis of them is made.In the forth part, the experiment results including open air low temperature experiment, anti-shake experiment, shipboard experiment and airborne experiment are shown. The flight detection experiment is carried out using micro-pulse lidar system aboard the CMS-3807 aircraft over the sea areas of Qingdao. The success of airborne flight experiment proves the reliability of hardware system in the aircraft platform and the feasibility of data processing and inversion algorithm. It provides valuable experience for the improvement of the next system. In the end, this paper is concluded and the target of system for the future is pointed out.