Atmospheric Remote Sensing: Instruments

Mini-MOPA CO2 Doppler Lidar

Mini-MOPA lidar instrument photo

Mini-MOPA lidar instrument in middle deck seatainer.

The Mino-MOPA lidar is housed in a mobile laboratory constructed from a modified sea-going cargo container. It provides vertical profiles of wind speed, wind direction, turbulence, aerosol species concentration (DIAL – introduction to Differential Absorption Lidar (DIAL) techniques), cloud geometry and microphysical parameters. Research applications include:

  • 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)

Contact: Alan Brewer


Basic Parameters Measured

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

Field Projects

Project NameDateLocation
RICORain in Cumulus over the Ocean Experiment (RICO)200501January 2005Eastern Atlantic and Western Caribbean
NEAQSNew England Air Quality Study (NEAQS)200207July-August 2002New Hampshire
EPICEastern Pacific Investigation of Climate (EPIC)200109September-October 2001Tropical Eastern Pacific
GroundWindsGroundWinds200009September 2000New Hampshire
AmmoniaAmmonia DIAL Measurements200003March-May 2000Boulder, Colorado
SOSSouthern Oxidants Study (SOS) 99199906June-July 1999Nashville, Tennsessee
Table MountainTable Mountain Doppler Experiment199811November 1998 - January 1999Boulder, Colorado
CARTCloud and Radiation Testbed (CART) / Atmospheric Radiation Measurement (ARM)199604April 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.

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, 293-296, Keystone, Colorado, 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.