In this paper a wind sensing lidar utilizing a Frequency Stepped Pulse Train (FSPT) is demonstrated. One of the advantages in the FSTP lidar is that it enables direct measurement of wind speed as a function of distance from the lidar. Theoretically the FSPT lidar continuously produces measurements as is the case with a CW lidar, but at the same time with a spatial resolution, and without the range ambiguity originating from e.g. clouds. The FSPT lidar utilizes a frequency sweeping source for generation of the FSPT. The source generates a pulse train where each pulse has an optical carrier frequency shifted a set quantity relative to the carrier frequency of the previous pulse. In the scheme presented here, the measured frequency depends on the distance from which the signal originates. The measured frequency is related to the Doppler frequency shift induced by the wind and an integer number of frequency shifts corresponding to a specific distance. The spatial resolution depends on the repetition rate of the pulses in the pulse train. Directional wind measurements are shown and compared to a CW lidar measurement. The carrier to noise ratio of the FSPT lidar compared to a CW lidar is discussed as well as the fundamental differences between the two systems. In the discussion we describe the most dominant noise sources in our system and what influences these have on the FSPT lidar's ability to measure under different scattering conditions.
|Journal||Proceedings of SPIE - The International Society for Optical Engineering|
|Publication status||Published - 2011|
|Event||Lidar Remote Sensing for Environmental Monitoring - San Diego, California, USA|
Duration: 1 Jan 2011 → …
Conference number: 12
|Conference||Lidar Remote Sensing for Environmental Monitoring|
|City||San Diego, California, USA|
|Period||01/01/2011 → …|
Bibliographical noteCopyright 2011 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
- Coherent lidar
- Laser anemometer
- Frequency modulation
- Fiber laser
- Range unambiguity