A Lidar for Remote Sensing of Optical Turbulence
A Lidar for Remote Sensing of Optical Turbulence

Author:

Publisher:

Published: 2000

Total Pages: 0

ISBN-13:

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Atmospheric turbulence affects the performance of missile defense platforms, such as the Airborne Laser (ABL). To understand the results of laser propagation tests on both the horizontal and inclined propagation paths, and to validate atmospheric turbulence prediction models, the vertical profile of the refractive index structure parameter is required. There is no current accepted lidar method for measuring profiles of the refractive index structure parameter. The differential image motion (DIM) has been established as the best way to measure the Fried parameter for "seeing" using a star or laser source. A new concept was proposed, DIM lidar, for measuring vertical profiles of the refractive index structure parameter. The lidar has the transmitter and receiver at the same end of the optical path and uses a pulsed lidar, atmospheric backscatter, and a range-gated receiver. A proof-of-concept test was performed and the experimental results validated the DIM lidar concept and showed that the refractive index structure parameter can be accurately measured.

Coherent Doppler Wind Lidars in a Turbulent Atmosphere
Coherent Doppler Wind Lidars in a Turbulent Atmosphere

Author: Viktor Banakh

Publisher: Artech House

Published: 2013-09-01

Total Pages: 277

ISBN-13: 1608076679

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Radiophysical tools for measuring atmospheric dynamics include sodars, Doppler radars, and Doppler lidars. Among these, coherent Doppler lidars (CDLs) have been considered the best for remote measurement of wind turbulence. This is important not only for understanding the exchange processes in the boundary layer, but also in the applied aspect, such as aviation safety. CDLs significantly extend possibilities of experimental investigation of not only wind turbulence, but also coherent structures such as aircraft wake vortices. The authors of this book conducted field tests of the developed methods of lidar measurements of the wind velocity, atmospheric turbulence parameters, and aircraft wake vortices. This valuable resource, containing over 500 equations based on original results from the authors’ work, gives professionals a comprehensive description of the operating principles of continuous wave and pulsed coherent Doppler lidars. This book studies the possibilities of obtaining information about wind turbulence from data measured by continuous wave and pulsed CDLs. The procedures for estimation are described, as well as algorithms for numerical simulation. Results on the vortex behavior and evolution are then presented.

Program to Perform Research on Use of Lidar for Range Resolved Turbulence Measurements
Program to Perform Research on Use of Lidar for Range Resolved Turbulence Measurements

Author: Warren P. Moskowitz

Publisher:

Published: 1989

Total Pages: 41

ISBN-13:

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The design of a lidar system capable of measuring remotely range resolved atmospheric turbulence is presented. The connection between the measured quantities and the accepted turbulence strength parameter (C sub n)-sq is developed theoretically. Simulations of an operating system have been made, and the results provide a measure of system capability. A typical value for (C sub n)-sq of 10 to the -16th power m to the -2/3 power at 3 km vertical range is measurable with a 200 m range resolution. Keywords: Atmospheric turbulence; Lidar; Optical turbulence. (jhd).

Optical Turbulence Forecasting
Optical Turbulence Forecasting

Author: Edmond M. Dewan

Publisher:

Published: 1980

Total Pages: 76

ISBN-13:

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This report is a tutorial on the effects of atmospheric turbulence upon systems which rely upon the propagation of LASER beams. In addition to providing a simplified presentation of turbulence theory and optical effects, it describes the state of the art of the new technique of radiosonde estimation of index of refraction fluctuations. Suggestions are given for future research which will help to answer current Air Force needs. The feasibility of some laser systems will depend upon the value of r0, the coherence length (which is related to “C2n” which in turn is related to the degree of turbulence). At present, the statistics of “r0” are inadequate.

Optical Turbulence Measurement - Investigations for Analysis of Laser Designator Spot Patterns
Optical Turbulence Measurement - Investigations for Analysis of Laser Designator Spot Patterns

Author: E. C. Crittenden

Publisher:

Published: 1983

Total Pages: 197

ISBN-13:

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This methodology investigation evaluates the feasibility of applying video image analysis techniques and instrumentation to characterize optical path turbulence for use in assessing the field performance of laser designator systems. The effort focused on adpating a C sub n sub 2 path weighted measurement technique developed by Dr. E. Crittenden, NPS, which uses a telescope mechanical slit scanner configuration for data acquisition. The Phase I effort presented in this report covers a theoretical analysis and empirical measurements to include a coincident path performance comparison of the scanner and a video system in a laboratory environment. Computer programs for analyzing the video data using either a real time digitizer or a digital storage oscilloscope were also developed. The results of the investigation demonstrate that the video technique can be applied to the measurement of C sub n sub 2 and a test plan to further validate the technique in a field environment is presented. (Author).