4 November 2003 Doppler lidar for boundary-layer measurements: must it be expensive?
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Proceedings Volume 5226, 12th International School on Quantum Electronics: Laser Physics and Applications; (2003) https://doi.org/10.1117/12.519495
Event: 12th International School on Quantum Electronics Laser Physics and Applications, 2002, Varna, Bulgaria
We review the basic theory of coherent Doppler Lidar for wind measurements and compare the new 1.55 μm technology with the traditional 10.6 μm (CO2 laser) system. There is now a huge selection of reasonably priced laser sources and optical components operating at 1.55 μm. The combination of a distributed feed-back diode laser oscillator and an erbium-doped fiber amplifier can provide 1 W or more of optical power over a linewidth much less than the Doppler shift of the return signal. Although the quantum efficiency is smaller at 1.55 μm than for a CO2 system, atmospheric scattering is stronger. Overall, the SNR should be significantly less than at 10.6 μm, but clear-air wind measurements should still be possible in most atmospheric conditions at eyesafe power densities. We will illustrate this technology using a system being developed and tested at UMIST. This is a bistatic, unfocussed system which uses fiber-optic delay lines to define a range of target distances. Preliminary measurements have been encouraging. The components used in our system were mostly available off the shelf to a total value of $k60-65. Of this, nearly $k40 represented the cost of the optical amplifier. The wider application of this technology will await these devices falling in price.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Michael Bennett, Michael Bennett, } "Doppler lidar for boundary-layer measurements: must it be expensive?", Proc. SPIE 5226, 12th International School on Quantum Electronics: Laser Physics and Applications, (4 November 2003); doi: 10.1117/12.519495; https://doi.org/10.1117/12.519495

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