+HummerH1 Posted November 28, 2006 Share Posted November 28, 2006 I have just purchased a 76CX and whilst I find it is faster at startup and more sensitive than my old 60CS it is nowhere near as accurate. Side by side my 60CS shows accuracy of 6-9ft whereas the new 76CX is no better than 15ft. I have just downloaded and installed the latest sofware for both the GPS and the chipset. Yes, I have WAAS enabled on both units. Anyone any ideas on this or should it go back? Bazzer Quote Link to comment
+Cardinal Red Posted November 28, 2006 Share Posted November 28, 2006 You are relying on an estimate of accuracy. And some of the older units were considered to be quite optimistic. Perhaps they are now using more realistic numbers. Try it in the real world before deciding if it's actually better or not. Quote Link to comment
+Sputnik 57 Posted November 28, 2006 Share Posted November 28, 2006 Do you have the same mapset loaded on each unit? EPE is a function not only of satellite reception and geometry, but also map accuracy. Also if the units are held very close together, they have been reported to interfere with each other. Quote Link to comment
+HummerH1 Posted November 28, 2006 Author Share Posted November 28, 2006 Yes, I have the same mapset on each, Topo's in my case. So how do you figure out which is right and which is wrong? Both unit's reporting the same sats but in the case of the newer CX unit it is showing one more. Bazzer Bazzer Do you have the same mapset loaded on each unit? EPE is a function not only of satellite reception and geometry, but also map accuracy. Also if the units are held very close together, they have been reported to interfere with each other. Quote Link to comment
Grasscatcher Posted November 28, 2006 Share Posted November 28, 2006 Go to NGS site or GC site and hunt for BM in your area. Find a local Benchmark near your location that has "Adjusted" horizontal coordinates. Those coordinates will be "Dead On" accurate, even closer than your hand held consumer GPSr is capable of. See which unit most closely matches those coordinates. Quote Link to comment
+HummerH1 Posted November 29, 2006 Author Share Posted November 29, 2006 Thanks, I will try that. I have just checked the 76CX and found that the EPE is the same regardless if WAAS is enabled or disabled. Bazzer Go to NGS site or GC site and hunt for BM in your area. Find a local Benchmark near your location that has "Adjusted" horizontal coordinates. Those coordinates will be "Dead On" accurate, even closer than your hand held consumer GPSr is capable of. See which unit most closely matches those coordinates. Quote Link to comment
Hertzog Posted November 29, 2006 Share Posted November 29, 2006 I have just purchased a 76CX and whilst I find it is faster at startup and more sensitive than my old 60CS it is nowhere near as accurate. Side by side my 60CS shows accuracy of 6-9ft whereas the new 76CX is no better than 15ft. I have just downloaded and installed the latest sofware for both the GPS and the chipset. Yes, I have WAAS enabled on both units. Anyone any ideas on this or should it go back? Bazzer As others have indicated, what you are seeing is basically a more conservative estimate of accuracy with the SiRF models. If you want to get a feel for the actual relative accuracies of the two units, just put them both into a 1 second track logging mode and let them sit and track for about an hour, then compare the size of the "blob" of track points. If your experience is like mine, the 60CS spread will be about twice that of the 76CX. By the way - the estimated accuracy calculation doesn't include a map contribution; the map errors are added to the estimated accuracy when calculating the radius of the circle displayed on the map page. Quote Link to comment
+HummerH1 Posted November 29, 2006 Author Share Posted November 29, 2006 Thanks, I'll try this and report back later on how I get on! At the moment I see that I constantly get better EPE on the 60CS than I do on the 76CX both seem to be locking on to the same sats. The difference being that the 76CX is showing markedly stronger signals than the 60CS Bazzer I have just purchased a 76CX and whilst I find it is faster at startup and more sensitive than my old 60CS it is nowhere near as accurate. Side by side my 60CS shows accuracy of 6-9ft whereas the new 76CX is no better than 15ft. I have just downloaded and installed the latest sofware for both the GPS and the chipset. Yes, I have WAAS enabled on both units. Anyone any ideas on this or should it go back? Bazzer As others have indicated, what you are seeing is basically a more conservative estimate of accuracy with the SiRF models. If you want to get a feel for the actual relative accuracies of the two units, just put them both into a 1 second track logging mode and let them sit and track for about an hour, then compare the size of the "blob" of track points. If your experience is like mine, the 60CS spread will be about twice that of the 76CX. By the way - the estimated accuracy calculation doesn't include a map contribution; the map errors are added to the estimated accuracy when calculating the radius of the circle displayed on the map page. Quote Link to comment
+MN-CACHE-TRACKER Posted December 2, 2006 Share Posted December 2, 2006 I have just purchased a 76CX and whilst I find it is faster at startup and more sensitive than my old 60CS it is nowhere near as accurate. Side by side my 60CS shows accuracy of 6-9ft whereas the new 76CX is no better than 15ft. I have just downloaded and installed the latest sofware for both the GPS and the chipset. Yes, I have WAAS enabled on both units. Anyone any ideas on this or should it go back? Bazzer The real question is do you need to get closer than 15" to find what your looking for???? dont mind me,Just my 2 cents. Quote Link to comment
+HummerH1 Posted December 2, 2006 Author Share Posted December 2, 2006 I wish that I get it it down to 15 inches I think you mean feet! The real answer is of course not, part of the fun of geocaching is the looking for the cache. Well for my son anyway. I do see a application for much better accuracy than currently available, hiking in the dark for example, I thinking military here. I have checked both units as suggested using the static track method and I find the 76CX gives me a much tighter "Blob" So maybe the EPE is not so important. As a matter of interest what is your West Coast EPE on a similar unit using the same chip set? Bazzer I have just purchased a 76CX and whilst I find it is faster at startup and more sensitive than my old 60CS it is nowhere near as accurate. Side by side my 60CS shows accuracy of 6-9ft whereas the new 76CX is no better than 15ft. I have just downloaded and installed the latest sofware for both the GPS and the chipset. Yes, I have WAAS enabled on both units. Anyone any ideas on this or should it go back? Bazzer The real question is do you need to get closer than 15" to find what your looking for???? dont mind me,Just my 2 cents. Quote Link to comment
bgarland Posted December 2, 2006 Share Posted December 2, 2006 I have a Map 76CSx and live in Tucson, Az. I typically see about a 9 ft EPE. Quote Link to comment
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