Raman LIDAR system detects the Raman backscattering radiation from nitrogen and Mie/Rayleigh backscattering radiation from atmospheric gases and aerosol particles. Lidar make use a laser to excite atmospheric constituents. The backscattered signal is observed using a telescope receiver, which collects the light and send it to the receiver optics. Optical chain selects specific wavelengths and directs them to photomultipliers. Once the lidar signal has been received it is amplified and digitized, for further analysis and visualization.
Raman LIDAR technical specifications
Emitter
Pulse laser source: Nd:YAG
Wavelength: 1064, 532, 355 nm
Energy/pulse: 105/45/65 mJ
Pulse duration: 5 ns
Repetition rate: 20 Hz
Laser beam diameter: 15 mm (expanded)
Laser beam divergence: 0.33 mrad
Receiver
Telescope type: Cassegrain
Telescope aperture diameter: 250 mm
Field of view: 0.5- 3 mrad (variable)
Elastic wavelength: 355 nm
Raman wavelength: 387 nm (N2)
Detection Unit
Transient recorder A/D Converter (12 bit at 20 MS/s), 250 MHz fast photon counting system
Detectors: Photomultiplier Tubes
Detection mode: Analog and photon counting
Data output: DAQ or Ethernet
General information
Voltage: 220~230 VAC, 50/60 Hz
Operating temperature: +15 to 40 0C
Humidity: 10 - 80% (non condensing)
Power: 1 kW (Nominal)/ 2.2 kW (Peak)
Spatial resolution (raw): 7.5 m
Raw signal range up to 122 km
Effective range: 0.05 – 16 km
Application
- Atmospheric transport and diffusion processes
- Mixed-layer depth and dynamic structure temporal evolution
- Boundary layer mixing height
- Clear air layering
- Cloud base height and cloud thickness (thin clouds only)
- Vertical profiling of aerosol optical parameters
- Aerosol layering in the troposphere
- Detection of aerosol emission sources