MoapaPk wrote:Day Hiker used his 60csx on Aconcagua. Bring Li batteries. WAAS coverage is really not needed, given the new sensitive chipsets.
I would guess Buz is right about the geoid correction; maybe Day Hiker can tell us his experiences on Aconcagua. The GPS ellipsoid-geoid correction is proprietary, and differs among companies. It is thought that most (newer) units take the calculated ellipsoid, and use interpolation in a look-up table to generate the correction; I'll bet a lot more care has gone into the correction in NA, than in SA.
It worked just fine, of course. My understanding is that it will work anywhere on the planet, unless you're shielding it from receiving satellite signals.
I took time-averaged readings on Aconcagua's summit with two GPSs, and the elevations were 22850 and 22855 feet. Considering the fact that peaks in the contiguous U.S. are not even surveyed within 5 feet of precision, I have little more belief in the "official" value of 22841 in Argentina than I do the readings I got. But even a time-averaged GPS reading on a summit (excellent, unobstructed view of the sky) cannot be trusted to within 10 feet, from my experience.
In other words, the readings I got were within the technology's precision of measurement of the "official" value, so I have no reason to suspect geoid or other error there.
I never use WAAS. Never needed it anywhere.
kheegster wrote:I would expect that the USAF needs to bomb stuff in the southern hemisphere as well, so I'd be shocked if GPS doesn't work there...
Yes, excellent point!