by JoeGrim » Tue Apr 24, 2018 1:16 pm
The problem is that there are uncertainties with GPS measurements. For example, if you walked 10 times around a flat 1/4-mile track, your GPS would indicate plenty of little ups and downs. Factors influencing how big these ups and downs include: the model of GPS device, how recently the GPS was turned on (newer devices self-calibrate after being turned on), the wind speed (affects the barometric altimeter via Bernoulli's principle), blockage of satellite signals (by foliage, terrain, and even your body), current weather (e.g., more humidity in the atmosphere degrades and slows the speed of the signal), current positions of satellites in the sky, solar storms, battery charge, and I'm sure there are plenty of other things. These uncertainties can sometimes be as low as 5 feet, or can be 100 feet or more. Therefore, last I knew, John does not use GPS readings to determine prominence. Your 302' GPS-indicated prominence definitely provides circumstantial evidence, but the 2' of prominence above 300' is definitely within the most conservative of error bars. Maybe if you hike it another 9 times, and each of those hikes indicate 300+' prominence, that might be enough? Anyway, it's great you've bagged this peak, in case it one day is found to be ranked. It looks like an awesome spot!