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The work described in this paper details the development of a low-cost, short-development time data acquisition and processing system for a coherent Doppler lidar. This was done using common laboratory equipment and a small software investment. This system provides near real-time wind profile measurements. Coding flexibility created a very useful test bed for new techniques.
Fixed scan against southeast sonic of 50m, 100m and 150m and supersite at 60m height.
fixed scan against southeast sonic of 50m, 100m and 150m and supersite at 60m height
fixed scan against southeast sonic of 50m, 100m and 150m and supersite at 60m height
A study has been completed to define a Shuttle experiment that solves the most crucial scientific and engineering problems involved in building a satellite Doppler wind profiler for making global wind measurements. The study includes: (1) a laser study to determine the feasibility of using the existing NOAA Windvan laser in the Space Shuttle spacecraft; (2) a preliminary optics and telescope design; (3) an accommodations study including power, weight, thermal, and control system requirements; and (4) a flight trajectory and operations plan designed to accomplish the required scientific and engineering goals. The experiment will provide much-needed data on the global distribution of atmospheric aerosols and demonstrate the technique of making wind measurements from space, including scanning the laser beam and interpreting the data. Engineering accomplishments will include space qualification of the laser, development of signal processing and lag angle compensation hardware and software, and telescope and optics design. All of the results of this limited Spacelab experiment will be directly applicable to a complete satellite wind profiler for the Earth Observation System/Space Station or other free-flying satellite.
These files contain 24 hour periods of data collected from the CLAMPS2 Halo Streamline XR+ Doppler lidar. The Doppler lidar conducts regular conical scans at a set elevation angle. These data are then passed through a typical VAD algorithm to retrieve horizontal wind speed and direction profiles. These data were collected during the TRACER project.
These files contain 24 hour periods of data collected from the SPARC Halo Streamline XR Doppler lidar. The Doppler lidar conducts regular conical scans at a set elevation angle. These data are then passed through a typical VAD algorithm to retrieve horizontal wind speed and direction profiles. These data were collected during the TRACER project.
These files contain 24 hour periods of data collected from the CLAMPS1 Halo Streamline XR+ Doppler lidar. The Doppler lidar conducts regular conical scans at a set elevation angle. These data are then passed through a typical VAD algorithm to retrieve horizontal wind speed and direction profiles. These data were collected during the AWAKEN project.
These files contain 24 hour periods of data collected from the CLAMPS2 Halo Streamline XR+ Doppler lidar. The Doppler lidar conducts regular conical scans at a set elevation angle. These data are then passed through a typical VAD algorithm to retrieve horizontal wind speed and direction profiles. These data were collected during the AWAKEN project.
A bibliography is given of 1460 references of the applications of lasers to atmospheric sciences. The subjects covered include: aerosols; clouds; the distribution and motion of atmospheric natural and man-made constituents; winds; temperature; turbulence; scintillation; elastic, Raman and resonance scattering; fluorescence; absorption and transmission; the application of the Doppler effect and visibility. Instrumentation, in particular lidar, is included, also data handling, and interpretation of the data for meteorological processes. Communications, geodesy and rangefinding are not included as distinct areas. The application to the atmosphere is covered, but not the ocean or its surface.
This nacelle mounted LiDAR is a Halo Photonics StreamLine XR Scanning Doppler LiDAR, and it is front facing to measure the inflow in front of the turbine.
This nacelle mounted LiDAR is a Halo Photonics StreamLine XR Scanning Doppler LiDAR, and it is front facing to measure the inflow in front of the turbine.
This nacelle mounted LiDAR is a Halo Photonics StreamLine XR Scanning Doppler LiDAR, and it is front facing to measure the inflow in front of the turbine.
This nacelle mounted LiDAR is a Halo Photonics StreamLine XR Scanning Doppler LiDAR, and it is front facing to measure the inflow in front of the turbine.
Practical space-based coherent laser radar systems envisioned for global winds measurement must be very efficient and must contend with unique problems associated with the large platform velocities that the instruments experience in orbit. To compensate for these large platform-induced Doppler shifts in space-based applications, agile-frequency offset-locking of two single-frequency Doppler reference lasers was thoroughly investigated. Such techniques involve actively locking a frequency-agile master oscillator (MO) source to a comparatively static local oscillator (LO) laser, and effectively producing an offset between MO (the lidar slave oscillator seed source, typically) and heterodyne signal receiver LO that lowers the bandwidth of the receiver data-collection system and permits use of very high-quantum-efficiency, reasonably- low-bandwidth heterodyne photoreceiver detectors and circuits. Recent work on MO/LO offset locking has focused on increasing the offset locking range, improving the graded-InGaAs photoreceiver performance, and advancing the maturity of the offset locking electronics. A figure provides a schematic diagram of the offset-locking system.
This dataset contains raw data from a Halo StreamLine XR scanning doppler lidar deployed at the BLOC site used to perform vertical stares.
A pulsed C02 Doppler lidar system is described and demonstration tests in ground-based and airborne flight operations are discussed. As a ground-based system, it can detect wind shears in thunderstorm gust fronts to a range of 6 km. When in the airborne configuration, the lidar can detect clear air turbulence in advance of the aircraft encountering clear air turbulence. The data provided by the lidar included turbulence location and intensity with intensity being indicated by the measured spectral width which is proportional to the wind gust velocity.
This paper describes recent measurements using coherent Doppler lidars operating at a wavelength of 10.6 microns aboard the NASA Ames Convair 990. The purpose of the measurements was to obtain data on the atmospheric wind fields and the distribution of the backscatter coefficient at 10.6 microns. A decription of the instruments is provided detailing the modifications incorporated following the 1981 test flights of the systems. The measurement program is outlined, and preliminary results are discussed.