At 02:48 PM 6/14/2010, James Ewen wrote: >If you can figure out how to deduce the crest of a hill buried in the >vertical variablility noise, have at it.
This has probably been considered by smarter minds that mine, but I'll toss it into the conversation anyway. As you are going up a hill, your altitude increases. After you crest the hill, your altitude decreases. By the time you've figured out that your altitude is really decreasing, you've passed the crest of the hill and it's too late to send a beacon at the hill top. However, I wonder if you could make this work by looking at the vertical acceleration in addition to the altitude. If altitude is increasing (subject to some filtering to get rid of the noise) and vertical acceleration decreases, then you are likely to be close to the top of the hill (_a_ hill, maybe not _the_ hill). Too simplistic? FWIW, my Garmin GPSmap 276C can display vertical acceleration. Don't know if it's available as an output or not. Interesting to watch as I drove between Phoenix and Flagstaff on I-17 a few years ago. Bob...
