In a message dated 01/05/01 10:20:09 PM Pacific Standard Time, [EMAIL PROTECTED] writes: > If nothing else it might be perfect for practicing XC. In a message dated 01/06/01 12:42:55 AM Pacific Standard Time, [EMAIL PROTECTED] writes: > Dumb question again: > What do we get with GPS on board? Kristopher, you have the primary use pegged already. Many of the current handheld GPS personal navigators have track logging ability, and would be ideal for scoring XC contests, at least. Unfortunately altitude logging is a rare feature among affordable RC sized units. Altitude logging on the GPS units used in full scale sailplanes is only certified when pressure altitude is the parameter being logged, due to lack of short term stability in GPS altitude readings. This requires additional parts in the unit which make it larger and more expensive. Prices and sizes are coming down though, and the FAI is looking at the possibility of allowing certified GPS altitude logging due to the recent removal of selective availability (SA) from the public GPS satellite signals. Virtually all full scale glider races are now scored with GPS flight data loggers, the old method being that of photographs taken of a turnpoint while in a specified "observation zone", a method that was slow, manpower intensive, and mistake prone. I use a Garmin handheld GPS in my glider on every flight, and upload the track log onto my home computer after each day of flying. The logging interval is adjustable from 1 second to as long as you want it. 4 seconds provides extremely fine resolution for a full scale glider, I imagine that a 1 second logging interval would by plenty for an RC glider, however at that 1 second interval, the Garmin on has about 1/2 hour of logging ability due to memory constraints. I use 10 seconds for most flights, and this still shows circling even in the smallest thermals. The commercial units designed specifically for flight data logging have much greater memory, but also cost $500-1200. Mark Navarre - RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
