" Take the difference between these GPS groundspeeds to get your windspeed." Correction " Take the difference between these GPS groundspeeds and your IAS to get your (close approx) windspeed."
--- On Mon, 9/27/10, ttcse/Tom <[email protected]> wrote: From: ttcse/Tom <[email protected]> Subject: Re: KR> GPS Verification To: "KRnet" <[email protected]> List-Post: [email protected] Date: Monday, September 27, 2010, 10:37 AM --- On Mon, 9/27/10, Mark Langford <[email protected]> wrote: From: Mark Langford <[email protected]> Subject: Re: KR> GPS Verification To: "KRnet" <[email protected]> List-Post: [email protected] Date: Monday, September 27, 2010, 8:33 AM Todd Thelin > Can someone walk me through how to get accurate wind > information at 7500' with only a GPS? > This doesn't answer your question, exactly, but if you're looking for your > true airspeed, one way is to go to http://www.csgnetwork.com/tasgpscalc.html > with your headings (90 degrees apart) and GPS speeds, and fill in the > blanks. ..." > Mark Langford > [email protected] > website www.n56ml.com A very simple approach to both of these...(winds aloft and TAS via GPS)... Fly a nice 360 or 720 at a constant airspeed and rate of turn, say Standard Rate or 1/2 Standard Rate. On a downwind heading you'll get the highest GPS groundspeed, on a upwind heading you'll get the lowest GPS groundspeed (factor in about 1 second GPS thinking time delay) Note these groundspeeds. Average these two to get your TAS. Take the difference between these GPS groundspeeds to get your windspeed. I figured this out long ago with my early Trimble when flying skydivers. Tom
