Mini-MOPA CO2 Doppler Lidar

example Mini-MOPA data image

Example Mini-MOPA data.

Mini-MOPA instrument trailer

The Mini-MOPA lidar is housed in a mobile laboratory constructed from a modified sea-going cargo container.

Applications

  • Boundary Layer Studies
    • Wind profiles
    • Turbulence and momentum flux measurements
    • Profiles and flux measurements of water vapor and ozone (under development)
    • Dual Doppler (future)
  • Cloud Studies
    • Cloud geometry
    • Cloud microphysical parameters (particle size and concentration)

Basic Parameters Measured

  • Range resolved radial velocity
  • Range resolved backscatter intensity
  • Dual wavelength differential absorption or backscatter (under development)

Field Projects

NEAQS (New England Air Quality Study)July/August 2002New Hampshire
EPIC (Eastern Pacific Investigation of Climage)September/October 2001Tropical Eastern Pacific
GroundWindsSeptember 2000New Hampshire
Ammonia DIAL MeasurementsMarch-May 2000Boulder, Colorado
SOS 99 (Southern Oxidants Study)June/July 1999Nashville, Tennsessee
Table Mountain Doppler ExperimentNov. 1998 - Jan. 1999Boulder, Colorado
CART (Cloud and Radiation Testbed)/ARM (Atmospheric Radiation Measurement)April 1996Ponca City, Oklahoma

Typical Specifications

Wavelength9.2 - 11.3 µm line tunable (fully eye-safe)
Pulse energy2 mJ
Pulse rate< 300 Hz
Pulse length0.5 - 10 µs
Wavelength switching rate< 50 Hz
ScanUpper hemisphere
Range Resolution> 60 m
Time Resolution0.3 sec (100 pulse avg.)
Minimum range90 m
Maximum range5 - 12 km
Velocity accuracy> 5 cm s-1
Comments
  • Radio frequency discharge technology in CO2 lasers decreases maintenance and increases lifetime.
  • C13 isotope laser gas mix will extend wavelength tuning range and decrease atmospheric CO2 absorption.
  • We are currently modifying the instrument to operate at two wavelengths for differential backscatter and absorption measurements.

Contact: Alan Brewer

References

Zhao, Y., "Line-pair selections for remote sensing of atmospheric ammonia by use of a coherent CO2 differential absorption lidar system." Applied Optics, 39(6):997-1007, 2000.

Brewer, W.A., and R.M. Hardesty, "Development of a dual-wavelength CO2 mini-MOPA Doppler lidar." OSA Coherent Laser Radar, Keystone, Colorado, 293-296, 1995.

Pearson, G.N., and B.J. Rye, "A high-pulse-repetition-frequency CO2 Doppler lidar for atmospheric monitoring." Rev. Sci. Instrum., 64, 1155-1157, 1993.