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Re: [RC] GPS, another question - Joe LongOn Mon, 13 Dec 2004 15:56:15 -0800, mtnriderII@xxxxxxxxx (Mary Sutliff) wrote: This is a really good question! I live in western Washington and our GPS is very unreliable in the forest. Some places it gets a good signal and then we go for quite aways with no signal. This causes very inconsistant readings and lots of inacurrances. What model do you have, and how old is it? The newer high-end units with a quad-helix antenna are quite sensitive and work a lot better in forest or deep canyons than older ones from only a few years ago. None are perfect, if the foliage is heavy enough the signal just can't get through, but the newer units are pretty good. Look for "quad helix antenna" on the specs when considering a purchase. (BTW, that's one drawback to the wrist models, they have a small antenna.) It also helps to carry it in such a way that the antenna has the best "view" of the sky (down in a coat pocket isn't good). The one I use can be seen at http://www.garmin.com/products/gpsmap60cs/ It includes a feature call WAAS which gives it accuracy down to ten feet. Not long ago I loaded the waypoints of the corners of a 23-acre piece of property I was going to look at (I got the latitude/longitude from an aerial photo). At each corner, when I got to where the GPS told me the corner was, the survey flag was within a few feet of where I was standing. I've found bench marks with it the same way, it will take me to within a few feet of the marker. If elevation is important to you, get one with a barometric altimeter. GPS elevation is not as accurate as barometric. You have to calibrate the barometric altimeter to the barometric pressure, but that's easy to do (if you don't know the pressure, you can set it to a known altitude; any contour line will do). Also, a standard GPS will not tell you compass direction when you're standing still -- it will only tell you which direction you're moving. One with an electronic compass will give you accurate compass headings even when you are not moving. In the Garmin model numbers, the "c" stands for a color display, and "s" for barometric altimeter and electronic compass. This is my third GPS, and the first one I've really used other than a plaything. The first two didn't have enough sensitivity, no color screen, no barometric altimeter or electronic compass. I find the color screen REALLY makes a big difference, you can read the info off of it so much more easily (and you get more effective detail for the screen size). I strongly recommend a color screen. -- Joe Long jlong@xxxxxxxx http://www.rnbw.com =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ridecamp is a service of Endurance Net, http://www.endurance.net. Information, Policy, Disclaimer: http://www.endurance.net/Ridecamp Subscribe/Unsubscribe http://www.endurance.net/ridecamp/logon.asp Ride Long and Ride Safe!! =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
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