Path profiles using Google Earth

My thanks go to Richard G3TFX for showing me this Google Earth feature, which may be of interest to VHF/UHF/SHF, microwave, nanowave and SOTA enthusiasts. I had no idea you could do this.

Using the ruler tool (in the menu at the top) in Google Earth click between two places. A line appears together with a distance measurement. Save this as a temporary file in Google Earth. Right click on this file in Google Earth and choose "show elevation profile" and a path profile between the 2 spots appears.

Google Earth path profile

The image above (screenshot from Google Earth - Google copyright acknowledged - will remove if a problem, but you are getting free publicity!) shows the non line-of-sight path between Burwell and the village of Stow-cum-Quy that I managed to span recently with my 481THz QRSS3 beacon using 100mm optics and a TX power of around 0.5W.

This does not appear to take any account of the Earth's curvature, so is probably only useful for relatively short distances. Does anyone know how to factor in this?

Looks a useful facility to me for seeing how close to line-of-sight a moderate length path is.

73s
Roger G3XBM

Non line-of-sight optical path profile

This is the path profile of my successful 3.6km QRSS3 cloudbounce non line-of-sight 481THz (red light) test on Feb 12th 2012. Sorry it is in feet and miles. The vertical scale is exaggerated, but it shows how non line-of-sight the path was. I used http://www.heywhatsthat.com/ to produce the data. This is a very useful site.  It is fascinating that such paths can be used successfully for optical frequency communications.