Raman lidar calibration device and calibration method thereof

Abstract

The invention discloses a Raman lidar calibration device and a calibration method thereof. The device is characterized in that the output end of a receiving fiber (13) is sheathed with a camera obscura (11), and the side surface of the output port of the receiving fiber (13) is provided with luminescent spectrum range covering nitrogen and a luminous diode (1) of the spectral band of gas to be calibrated; the receiving fiber (13) and the light path of the luminous diode (1) are provided with a collimation lens (10) and a beam splitting sheet (5); the reflective light path of the beam splitting sheet (5) is provided with a first optical filter (3) and a first detector (2); and a transmission light path is provided with a second optical filter (7) and a second detector (6). The method is as follows: the light intensity P1 of the spectral band of gas to be calibrated and the light intensity P2 of the nitrogen which are obtained by the first detector (2) and the second detector (6) as well as I lambda N and I lambda X in the intensity expression are substituted into a Raman lidar equation to obtain the density distribution of the gas to be calibrated. The device has simple structure and convenient use and can be used for the quantitative measurement of atmospheric parameters.

Description

technical field The invention relates to a laser radar calibration device and a calibration method, in particular to a Raman (Raman) laser radar calibration device and a calibration method. Background technique Raman lidar is a high-tech product of optomechanical integration, which is mostly used for quantitative measurement of atmospheric parameters. Since the Raman lidar system is complex and involves many functional components, it is very easy to cause changes in the Raman laser constants due to changes in the parameters in the system, which in turn cause changes in the lidar constants. For this reason, in the practical application of Raman lidar, it is often necessary to calibrate the Raman lidar constants. For example, in the "Atmospheric Science" Volume 24, Issue 6, published in November 2000, the article "Raman Lidar Detection of Water Vapor Mixing Ratio in the Atmosphere" once disclosed a method to determine the system calibration constant C by meteorological soundi...

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Problems solved by technology

However, this determination system calibration constant C w Firstly, it is necessary to use a sounding balloon equipped with a meteorological radiosonde, which not only increases the cost of measurement, but also is inconvenient, and it is not easy to carry out real-time quantitative measurement of the water vapor mixing ratio in the atmosphere. There is also a comparison with the detection results of the water vapor profiler to determine the Raman lidar constant, but there are still defects in the practical application of the high price of the water vapor profiler, which is also an insurmountable obstacle for the practical application of the Raman lidar. Second, it is only applicable to the calibration of the quantitative measurement of the water vapor mixing ratio in the atmosphere, but not to the calibration of other gases in the atmosphere, such as carbon dioxide gas, aerosol Calibration when making quantitative measurements

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