Stumpy434 Posted March 7, 2008 Share Posted March 7, 2008 I just started Geocaching and bought a Garmin Venture HC and noticed the default setting for WAAS is off. Should I enable it and why? All feedback will be appreciated. Quote Link to comment
+Red90 Posted March 7, 2008 Share Posted March 7, 2008 Whenever you are in North America, leave it on. It improves accuracy. Quote Link to comment
+Dryphter Posted March 7, 2008 Share Posted March 7, 2008 WAAS As Red90 says, it improves accuracy. Quote Link to comment
+Parabola Posted March 8, 2008 Share Posted March 8, 2008 WAAS is basically a land based correction system that makes your GPSr more accurate. Mine is on all the time. Quote Link to comment
+JustinHEMI Posted March 8, 2008 Share Posted March 8, 2008 Speaking of WAAS, other than enabling it, is there any way to tell that it is..."on" on a 60csx? My old sportrak used to say WAAS. Thanks Justin Quote Link to comment
+coggins Posted March 8, 2008 Share Posted March 8, 2008 Speaking of WAAS, other than enabling it, is there any way to tell that it is..."on" on a 60csx? My old sportrak used to say WAAS. Thanks Justin On the Sat page you will see the letter "D" in the level bars: Quote Link to comment
+jotne Posted March 8, 2008 Share Posted March 8, 2008 You can see its on when you see satellite number 33 and higher, like picture above (39) The "D" does mean that it as downloaded correction for that specific satellite. Quote Link to comment
+JustinHEMI Posted March 9, 2008 Share Posted March 9, 2008 Thank you very much! Justin Quote Link to comment
+Not the Mama! Posted March 9, 2008 Share Posted March 9, 2008 Whenever you are in North America, leave it on. It improves accuracy. Is WAAS therefore not available in Europe? Quote Link to comment
+jotne Posted March 9, 2008 Share Posted March 9, 2008 We do have a system that do work the same way as WAAS and it's name is EGNOS. So when you are in Europe and see "D" in statellite bars, you have EGNOS corrections. In Japan it's called MSAS. Quote Link to comment
bigbill25 Posted March 12, 2008 Share Posted March 12, 2008 Back in my GPS V days, the manual warned that turning on WAAS would slow system performance and negatively affect battery life. Is that no longer true with the latest units? I'm running an eTrex Legend HCx. Thanks. --Bill Quote Link to comment
+julianh Posted March 12, 2008 Share Posted March 12, 2008 Back in my GPS V days, the manual warned that turning on WAAS would slow system performance and negatively affect battery life. Is that no longer true with the latest units? I'm running an eTrex Legend HCx. Thanks. --Bill On the current generation Garmins, there is no discernible impact on speed or battery life with WAAS on. (Do a search for "battery life" on this forum to see some posts which have measured battery current with WAAS on and off.) Note that it will take a few minutes to get a differential lock, but the speed of getting a 3D fix for a cold or warm start, paging between screens, etc, is unaffected. Hope this helps! Quote Link to comment
bigbill25 Posted March 12, 2008 Share Posted March 12, 2008 On the current generation Garmins, there is no discernible impact on speed or battery life with WAAS on. (Do a search for "battery life" on this forum to see some posts which have measured battery current with WAAS on and off.) Note that it will take a few minutes to get a differential lock, but the speed of getting a 3D fix for a cold or warm start, paging between screens, etc, is unaffected. Hope this helps! Indeed it does! Just makes me wonder why Garmin has it default to off --Bill Quote Link to comment
+julianh Posted March 13, 2008 Share Posted March 13, 2008 Indeed it does! Just makes me wonder why Garmin has it [WAAS] default to off --Bill There is some question as to whether having WAAS on when you are out of range of WAAS ground-station coverage will actually degrade accuracy. (Note that I am talking about actual positional accuracy, not just the estimate of accuracy that the GPSr reports, which is NOT the same thing!) This was certainly the case on the older units, but I suspect that Garmin may have modified the algorithm so as to disregard ionosphere corrections when you are out of range. (Note - pure supposition - Garmin don't say.) I am based in Australia, and am still experimenting with my Summit HC. So far, having WAAS on (even though I am well outside the base-station coverage) doesn't seem to have adversely affected my accuracy, but I will need a lot more experimentation to be 100% confident this is the case. Accuracy with WAAS off will generally be "very good" (5 metres or so seems to be pretty typical) wherever you are located in the world. If you are in North America (and possibly Europe - don't know quite how Garmins use the EGNOS signals), you should find accuracy is generally somewhat better with WAAS on - say 2 to 3 metres. If you are outside North America / Europe and have WAAS on with an older unit, you can definitely get worse accuracy from time to time (due to application of incorrect ionosphere corrections, I believe). If you are outside North America Europe and have WAAS on with a current generation Garmin unit, you MAY not get any accuracy degradation, but I haven't seen anything yet which would convince me that the accuracy is any better. Hope this helps. Quote Link to comment
Trapper SG Posted March 13, 2008 Share Posted March 13, 2008 Greetings all! Another newbie here... just bought an explorist 600 used of course and was wondering how I can check to see if WAAS is enabled (or on). Will I also see a "D" show up in the tracking page? I am not seeing it track anything above 32. I have downloaded and installed the latest firmware as of a couple of days ago. Would appreciate any and all help. Quote Link to comment
bigbill25 Posted March 13, 2008 Share Posted March 13, 2008 There is some question as to whether having WAAS on when you are out of range of WAAS ground-station coverage will actually degrade accuracy. (Note that I am talking about actual positional accuracy, not just the estimate of accuracy that the GPSr reports, which is NOT the same thing!) This was certainly the case on the older units, but I suspect that Garmin may have modified the algorithm so as to disregard ionosphere corrections when you are out of range. (Note - pure supposition - Garmin don't say.) A note about "estimate of accuracy that the GPSr reports": On my Legend HCx, the reported accuracy does not take into account WAAS. If I am getting a accuracy estimate of say, 15 feet, without WAAS, then turn it on, it still shows 15 feet... I would expect it to change somewhat. Same thing if I turn it off: no change... --Bill Quote Link to comment
+GPSlug Posted March 14, 2008 Share Posted March 14, 2008 A note about "estimate of accuracy that the GPSr reports": On my Legend HCx, the reported accuracy does not take into account WAAS. If I am getting a accuracy estimate of say, 15 feet, without WAAS, then turn it on, it still shows 15 feet... I would expect it to change somewhat. Same thing if I turn it off: no change... --Bill How long do you give it for the accuracy to change? It will take several minutes to get all the corrections. It may even be showing 'D's when it has the orbit and clock corrections but not the full iono grid yet. One thing that WAAS will do for the accuracy estimate is make the estimate better. In particular, it will have a better idea of how big the ionospheric error may be when otherwise your GPSr basically has to guess. That's why sometimes people see the EPE actually get bigger when they turn on WAAS. Quote Link to comment
bigbill25 Posted March 14, 2008 Share Posted March 14, 2008 I didn't give it much time when testing the WAAS-off to WAAS-on. However, when I did the WAAS-on to WAAS-off, the unit had been tracking with WAAS-on for about 30 minutes... I will have to play with it further. --Bill Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.