 |
Re: [RC] long /limited distance - Truman PrevattThe spec on GPS is 10 meters ( about 30 feet) 50% CEP. I believe it 50%, and I'm too lazy to drag out my spec. That means that 50% of the time the true location is within 10 meters of the calculated location. The military units are. This is only for point locations. The GPS system does not have a spec on distance measurements. The error in distance is a factor of a lot more than just the point position error. It's a function of how the position estimates are used to estimate distance, the samping rate, the complexity of the algorithm used, even the arithematic used in the processor.So I would trust a lot of what GPS says - especially under foliage. The frequency GPS uses in not foliage penetrating. But this whole discussion is pretty well down in the nits anyway. A max error of 2.5 miles is 5%. I would expect that there are very few trails out there that have a true distance withing 50% of what it measured to be - unless it's all driveable and the odemeter has been recently calibrated. Truman Paul Latiolais wrote: So THAT means (following David's logic) that a 50 mile ride by definition must be OVER fifty miles,...because, as a practical matter, it must be measured with a certain limit on the level of accuracy. Hence you must always be over and round down to 50 miles, to insure that it is AT LEAST fifty miles. ============================================================ At the end of the day maybe the definition of endurance isn't the length of the ride but rather the spirit in which it is ridden. ~ Maryanne Stroud Gabani ridecamp.net information: http://www.endurance.net/ridecamp/ ============================================================
|