Can anyone dumb down how a wind profiler (like the one in Slater) works? In searching for an explanation, there's one unfamiliar term I'm finding: Bragg Scattering. I can't find any simple explanations for it, but it looks like something similar to something we did in Phys 222 with the resulting phase shift of relfection of radiation entering a boundary with a thickness and different refractive index. My real question about wind profilers is, while I understand they use the Doppler effect, I always thought that to measure a velocity (accurately), the particles being measured had to be moving approximately parallel to the radiation. How can one find an exact velocity with direction not being simply towards or away from the radar source? Also, seeing how there seems to be some sensitivity to the difference in refractive indexes through the atmosphere, how does that change with elevation and/or pressure/density? Isn't it possible to have multiple "layers" with the same index?

Here is the only link that I know of that talks about the wind profilers, it has diagrams on it as well. Maybe that will help...

http://www.profiler.noaa.gov/npn/aboutProfilerData.jsp

The link provided does a very good job. You are right about about a radar pulse only having information toward or away from the source. That is why profilers use three beams. From the doppler shift of three beams I can gather enough information to infer a three dimensional wind field.

-Dave Flory