Atmospheric Remote Sensing: Instruments

Ozone Profiling Atmospheric Lidar (OPAL)

OPAL lidar instrument
OPAL lidar mobile laboratory aboard ship


Used to monitor ozone and aerosol formation, evolution and transport. Research applications include:

  • Ozone formation/evolution monitoring
  • Ozone transport studies
  • Aerosol in polluted areas

Basic parameters measured:

  • Ozone concentration profiles
  • Particle backscatter profiles

Typical Specifications

Wavelength266 nm289 nm299 nm355 nm
Pulse energy6 mJ2 mJ2 mJ6 mJ
Pulse rate1 - 10 Hz
Scanning DirectionsVertical, horizontal, and in a single vertical plane
Minimum range60 m
Maximum range1.5 - 3 km6 - 7 km6 - 7 km9 km
Range Resolution15 m
Maximum range3 km
Range Resolutionbelow 1 km: 60 - 90 m
1 - 2 km: 100 - 150 m
2 - 3 km: 150 - 300 m
AccuracyBetter than +/- 10 ppb
Specifications prior to 1999:
Wavelength266 nm289 nm355 nm
Pulse energy20 mJ1 mJ6 mJ
Pulse rate2 - 10 Hz
Scanning DirectionsVertical, horizontal, and in a single vertical plane
Minimum range15 - 60 m
Maximum range1.5 - 3 km6 - 7 km10 km
Maximum range3 km
AccuracyBetter than +/- 10 ppb

Field Projects

Project NameDateLocation
TexAQS 2006Texas Air Quality Study 2006200607July-September 2006Houston, Texas
NEAQS 2004New England Air Quality Study 2004200406June-August 2004 New Hampshire
NEAQSNew England Air Quality Study200207July-August 2002 New Hampshire
Aircraft Plume Study200105May 2001
TexAQSTexas Air Quality Study200008August-September 2000Houston, Texas
SOSASouthern Oxidants Study SuperSite199908August 1999Atlanta, Georgia
SOSSouthern Oxidants Study 99199906June-July 1999Nashville, Tennessee
SCOSSouthern California Ozone Study199706June-October 1997El Monte, California
LIFTLidars In Flat Terrain199608August 1996 Champaign/Urbana, Illinois
VOTEVictorville Ozone Transport Experiment199508August 1995Victorville, California
LAFRSLos Angeles Free Radical Study199309September 1993Los Angeles, California
DavisDavis Intercomparison Experiment199307July 1993Davis, California


Zhao, Y., R.D. Marchbanks, and R.M. Hardesty, Environmental Technology Laboratory's Transportable Lower Troposphere Ozone Lidar and Its Applications in Air Quality Studies, 42nd SPIE Annual meeting, Application of Lidar to Current Atmospheric Topics II, Proceedings of SPIE #3127, July 1997, 53-62.

Zhao, Y., R.M. Hardesty, and J.E. Gaynor, Demonstration of a new and Innovative Ozone Lidar's Capability to Measure Vertical Profiles of Ozone Concentration and Aerosol in the Lower Troposphere, Final report to the California Air Resources Board, December 1994.

Zhao, Y., R.M. Hardesty and M.J. Post, A Multibeam Transmitter for Signal Dynamic Range Reduction in Incoherent Lidar Systems, Applied Optics 45, 7623-7632, 1992.

Zhao, Y., J.N. Howell, and R.M. Hardesty, Transportable Lidar for the Measurement of Ozone Concentration and Aerosol Profiles in the Lower Troposphere, A&WMA/SPIE International Symposium on Optical Sensing for Environmental Monitoring, 11-14 October 1993, Atlanta, Georgia, 310-320.