242
C. Weitkamp
10.6 Conclusion
In the present paper an attempt is made to describe the lidar principle of operation and to show
a few examples of lidar applications in the measurement of atmospheric constituents including
aerosols. The concentration limit for lidars can be stated to be around 10 parts in 10 9 , or 10
ppb, although a few substances can be measured in concentrations many orders of magnitude
below that limit. Measurement capabilities in clouds are summarized in Table 10.8.
For gaseous pollutants immission, emission, and transport data can be obtained, lifetimes
determined, and sources localized. Horizontal, vertical and slant profiles as well as fans of such
profiles provide three-dimensional distributions. Snapshots and time series can be generated;
the potential of measuring rare events by automatically triggered systems is only beginning to
be investigated.
What is still difficult to achieve with lidar is all-weather operation, although measurements in
light rain can be carried out. Also fully automated long-term unattended service and, thus,
worldwide target coverage by lidars on board satellites is not available today except for the
very simplest implementations of the technique.
10.7 References
For abbreviations (ILRC, ISTP, ORSA, SPIE) see Section" Additional Reading"
Ansmann A (1984) Diplomarbeit, Universitiit Hamburg
Ansmann A (1989) Bodengebundene DIAL-Wasserdampfmessung: Beriicksichtigung der
Dopplerverbreiterung der Laserlinie durch Rayleighriickstreuung. Dissertation, Universitiit
Hamburg. Hamburger Geophysikalische Einzelschriften, Reihe A, Heft 89: 69 p
Ansmann A, Bosenberg J (1987) Correction scheme for spectral broadening by Rayleigh
scattering in differential absorption 1idar measurements of water vapor in the troposphere.
Applied Optics 26: 3026-3032
Ansmann A, Riebesell M, Weitkamp C (1990) Measurement of atmospheric aerosol
extinction profiles with a Raman lidar. Optics Letters 15: 746-748
Ansmann A, Bosenberg J, Brogniez G, Elouragini S, Flamant PH, Klapheck K,
Linn H, Menenger L, Michaelis W, Riebesell M, Senff Ch, Thro P-Y, Wandinger
U, Weitkamp C (1993) Lidar Network Observations of Cirrus Morphological and Scattering
Properties during the International Cirrus Experiment 1989: The 18 October 1989 Case Study
and Statistical Analysis. Journal of Applied Meteorology 32: 1608-1622
Ansmann A, Riebesell M, Wandinger U, Weitkamp C, Michaelis W (1991a) Combined
Raman elastic-backscatter lidar for the independent measurement of aerosol backscatter and
extinction profiles. Report GKSS 91/E/42: 8 p
Ansmann A, Riebesell M, Wandinger U, Weitkamp C, Michaelis W (1991b) Klett
forward-backward integration for model-independent determination of the aerosol extinctionto-backscatter ratio. GKSS 91/E/43: 8p
Ansmann A, Riebesell M, Wandinger U, Weitkamp C, Voss E, Lahmann W, Michaelis W (1992) Combined Raman Elastic-Backscatter LIDAR for Vertical Profiling of Moisture, Aerosol Extinction, Backscatter, and LIDAR Ratio. Applied Physics B 55: 18-28
Ansmann A, Wandinger U, Riebesell M, Weitkamp C, Michaelis W (1992) Independent measurement of extinction and backscatter profiles in cirrus clouds by using a combined
Raman elastic-backscatter lidar. Applied Optics 31: 7113-7131
C. Weitkamp
10.6 Conclusion
In the present paper an attempt is made to describe the lidar principle of operation and to show
a few examples of lidar applications in the measurement of atmospheric constituents including
aerosols. The concentration limit for lidars can be stated to be around 10 parts in 10 9 , or 10
ppb, although a few substances can be measured in concentrations many orders of magnitude
below that limit. Measurement capabilities in clouds are summarized in Table 10.8.
For gaseous pollutants immission, emission, and transport data can be obtained, lifetimes
determined, and sources localized. Horizontal, vertical and slant profiles as well as fans of such
profiles provide three-dimensional distributions. Snapshots and time series can be generated;
the potential of measuring rare events by automatically triggered systems is only beginning to
be investigated.
What is still difficult to achieve with lidar is all-weather operation, although measurements in
light rain can be carried out. Also fully automated long-term unattended service and, thus,
worldwide target coverage by lidars on board satellites is not available today except for the
very simplest implementations of the technique.
10.7 References
For abbreviations (ILRC, ISTP, ORSA, SPIE) see Section" Additional Reading"
Ansmann A (1984) Diplomarbeit, Universitiit Hamburg
Ansmann A (1989) Bodengebundene DIAL-Wasserdampfmessung: Beriicksichtigung der
Dopplerverbreiterung der Laserlinie durch Rayleighriickstreuung. Dissertation, Universitiit
Hamburg. Hamburger Geophysikalische Einzelschriften, Reihe A, Heft 89: 69 p
Ansmann A, Bosenberg J (1987) Correction scheme for spectral broadening by Rayleigh
scattering in differential absorption 1idar measurements of water vapor in the troposphere.
Applied Optics 26: 3026-3032
Ansmann A, Riebesell M, Weitkamp C (1990) Measurement of atmospheric aerosol
extinction profiles with a Raman lidar. Optics Letters 15: 746-748
Ansmann A, Bosenberg J, Brogniez G, Elouragini S, Flamant PH, Klapheck K,
Linn H, Menenger L, Michaelis W, Riebesell M, Senff Ch, Thro P-Y, Wandinger
U, Weitkamp C (1993) Lidar Network Observations of Cirrus Morphological and Scattering
Properties during the International Cirrus Experiment 1989: The 18 October 1989 Case Study
and Statistical Analysis. Journal of Applied Meteorology 32: 1608-1622
Ansmann A, Riebesell M, Wandinger U, Weitkamp C, Michaelis W (1991a) Combined
Raman elastic-backscatter lidar for the independent measurement of aerosol backscatter and
extinction profiles. Report GKSS 91/E/42: 8 p
Ansmann A, Riebesell M, Wandinger U, Weitkamp C, Michaelis W (1991b) Klett
forward-backward integration for model-independent determination of the aerosol extinctionto-backscatter ratio. GKSS 91/E/43: 8p
Ansmann A, Riebesell M, Wandinger U, Weitkamp C, Voss E, Lahmann W, Michaelis W (1992) Combined Raman Elastic-Backscatter LIDAR for Vertical Profiling of Moisture, Aerosol Extinction, Backscatter, and LIDAR Ratio. Applied Physics B 55: 18-28
Ansmann A, Wandinger U, Riebesell M, Weitkamp C, Michaelis W (1992) Independent measurement of extinction and backscatter profiles in cirrus clouds by using a combined
Raman elastic-backscatter lidar. Applied Optics 31: 7113-7131