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Radar satellites currently use IR measurements of cloud albedo to determine the water mass, density, and altitude of clouds, to understand precipitation for weather forecasts.

I am studying a proposition for a laser measurement apparatus intended to image 3D structure of whirls of cloud vapor in high resolutions, up to 30 kilometers awaym to capture clear point clouds of cumulonimbus.

It's to see into complex weather fronts with hot and cold air colliding in complex vortices, and to advance the science of meteorology.

If you can measure the speed of light in meters then you can measure the structure of a cloud in 3D...

If you shine a laser in every direction from the top of a mountain, in the form of small packets of photons, and measure the complex reaction of the light as it diffuses in the cloud and eventually reflects back to the base station (or to triangulation points), while giving the photons time to travel 30km into the sky prior to sending another burst, It should be possible to measure the density of the clouds in meter resolution at high frequencies.

High speed cameras should be able to capture the response of cloud traversing laser in the sky fast enough to plot thousands of points representing up to 10,000 photon traversals of the sky every second to a distance of 30 kilometers.

My grasp of water vapor interaction with different frequencies is very hazy, I am clearly falling into a technical pit that you will rapidly shovel back over me.

What wavelengths and physical interactions can travel through a cloud transparently enough to be measured into point clouds of sub meter resolution, what algorithms would be involved, and how to deal with the problem of diffraction by raindrops?

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  • $\begingroup$ Sorry, i hope the question is ok for the forum, it seems to be more measurement apparatus and physics than earth sciences. Certainly only a physicist could know if it were possible. $\endgroup$ – com.prehensible Jul 31 '16 at 14:57
  • $\begingroup$ Ranging and detection with light rather than radio band signals is often called "lidar" in analogy with "radar", which might give you an extra search term. $\endgroup$ – dmckee Jul 31 '16 at 15:54
  • $\begingroup$ However, I fear that the question in it's current form is overly broad for Physics. See the tour, the help center and in particular the items on what question are on- and off-topic. $\endgroup$ – dmckee Jul 31 '16 at 15:57
  • $\begingroup$ Indeed, this is a solved lidar application. Note that free space use of lasers will require good safety analysis and documentation. $\endgroup$ – Jon Custer Jul 31 '16 at 16:31
  • $\begingroup$ Thanks, sorry it was a late night hazey thought. Space born lidar cloud measurement began in 2003 with GLAS lidar which works above 2500Hz probablyu and at 523nm wavelengths, which has resolution of 76.8 m vertical and 172 m along track. 1m resolution must be possible with with different wavelengths and refined lidar. i want to see some thunderstorms in 3D at fine resolutions! NASA has ACE proposed satellite and ESA/JAXA has EarthCARE which has radar and lidar and which is delayed to 2018 due to lidar problems. I can't find what the resolution of the lidar will be for that. $\endgroup$ – com.prehensible Aug 1 '16 at 7:33

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