Research On LED Light Source Mie Scattering Aerosol Detection Radar System

Radar which based on laser is an active modern optical remote sensing device,having a laser light source.It is widely used in the fields of atmospheric environmental monitoring with high spatial and temporal resolution and continuous detecting capacity.But subject to the limitations of the laser wavelength.it's application in the field of aerosol detection is affected.LED light source has many advantages,which is better than laser as the source of atmospheric radar.With the characteristics of rich in wavelength of LED,it's easy to detect optical properties of aerosol in the specific wavelength and gain it's particle size distribution.In addition,by using LED as an radar light source,the equipment miniaturization and low-cost is becoming possible.Firstly,this topic analyzed the feasibility of aerosol detection by using LED light source as radar detection source,and the Mie scattering aerosol detection radar system witch was suited for LED.530nm wavelength LED was adopted to comply with the safety standards of the human eyes.The multiple LED array light source was designed to solve the shortage of energy of the single LED.The light source collimation was implemented by using the optical system which combines lens group with the light guide rod.Using cassegrain telescope as an optical receiver,the atmospheric echo signal was received and detected by PMT.The computer data acquisition system was designed.The data acquisition and atmospheric extinction coefficient retrieval program was written by Lab VIEW.Secondly,the detection capability of the system was simulated based on radar equation,atmospheric model and system parameters.In this paper,the receiver field of view,the telescope diameter,and the influence of light emitting duration for detection results,and the geometric overlap factor of the system was calculated and analyzed.Finally,the LED radar system was built and the aerosol detection experiment was carried out.The aerosol back scatter echo signal was collected,and the data retrieve was performed by Klett method,the distribution curve of the aerosol extinction coefficie nt was obtained.Through the analysis of experiment data,the feasibility of the LED Mie scattering aerosol detection radar was verified.