yakmanz Posted July 16, 2002 Share Posted July 16, 2002 If I have WASS turn on on my GPS and don't receive any sats on it , does it affect my accuracy? Quote Link to comment
+Desert_Warrior Posted July 16, 2002 Share Posted July 16, 2002 quote: If I have WASS turn on on my GPS and don't receive any sats on it , does it affect my accuracy? Think about this. If you don't recieve "ANY" satellites, I would suppose that would affect accuracy. But I think you mean "ANY WASS" satellites. Is this correct. I do not know about your machine. My E-Trex Venture seems to be slugish with WAAS enabled and a bad angle to the WAAS satellite. Even with a good WAAS link, I only see a change in elevation. This may be imagined. But I see no real change in lat-lon accuracy. However, I am still new at this. I do just as well with a map-compass-pencil-protractor as I do with a GPS. IMHO, YMMV, ETC. Mike. KD9KC El Paso, TX. Quote Link to comment
+Prime Suspect Posted July 16, 2002 Share Posted July 16, 2002 quote:Originally posted by yakmanz:If I have WASS turn on on my GPS and don't receive any sats on it , does it affect my accuracy? No. Quote Link to comment
+LarsThorwald Posted July 16, 2002 Share Posted July 16, 2002 "No" seconded. "One should never begin a journey by heading in the wrong direction." Quote Link to comment
+JeeperJohn Posted July 18, 2002 Share Posted July 18, 2002 My batteries seem to get used up really fast when I have WAAS enabled. Quote Link to comment
Couch_Potato Posted July 18, 2002 Share Posted July 18, 2002 In my very non-scientific investigation method I've found that WAAS has no improvement in accuracy over non-WAAS. Over the past couple weeks I'v tried WAAS/non-WAAS comparisons in several different places where I have good satellite coverage. With 6-8 satellites locked in and recieving differential information on all of them in WAAS mode, the improvement from WAAS is only 1-2 ft in accuracy. It seems that not using WAAS can be just as accutarate as using WAAS so I say turn WAAS off. I'm not lost! I just don't know where I am. Quote Link to comment
+TeamCNJC Posted July 18, 2002 Share Posted July 18, 2002 In addition to receiving differential signals from a WAAS satellite, you also have to be in proximity to a ground station. As I understand it, the ground station receives the signal from the satellites in view, calculates the error in the signal (because the ground station doesn't move), and that error correction is uploaded to the WAAS bird that transmits it to all WAAS capable units. The farther away you get from a ground station, the less impact the differential will have. Even though you may be receiving a differential signal, it may not be adding a significant improvement to your accuracy. Here in MN, I've seen a decrease in the EPE displayed on my GPSr, but the availability of WAAS signals has not influenced my ability to find a cache. As always, YMMV. Here's a question for those who are more knowledgable then me - is there a listing of WAAS ground stations, and what is the radius of the ground station's influence? -Craig/TeamCNJC ... Two roads diverged in a wood, and I-- I took off through the thorns, chest high, ... Quote Link to comment
+Trafcon Posted July 18, 2002 Share Posted July 18, 2002 As stated above, WAAS does eat away at batteries since it utilizes more power from the receiver. Also there is little improvement in accuracy unless you are in a good area (mostly at sea) and you continually receive the WAAS signal for 30 minutes or more. I've gotten WAAS to improve my EPE on my Garmin V a maximum of from 16 feet to 10 feet. This was in good conditions on the Oregon coast. KTF !!! GBWY !!! Quote Link to comment
Couch_Potato Posted July 19, 2002 Share Posted July 19, 2002 quote:Originally posted by TeamCNJC:Here's a question for those who are more knowledgable then me - is there a listing of WAAS ground stations, and what is the radius of the ground station's influence? I don't claim to be an expert, but I was able to dig up a map of the 25 north America WAAS reference stations: And though I can't find the reference now, I seem to recall somewhere I did read how close you have to be to the reference station to benefit from the corrections. If only I could remember what it is. I'm not lost! I just don't know where I am. Quote Link to comment
+TeamCNJC Posted July 22, 2002 Share Posted July 22, 2002 ... but I did remember reading this before. On the GPS Information page concerning WAAS: quote:3) Also, a handheld must be within a region serviced by at least one of the monitoring stations supplying corrections to the Master Control site. The distance might be somewhere in the range of 500 miles or less, because the ionospheric delays are fairly local in nature and change rapidly. -Craig/TeamCNJC ... Two roads diverged in a wood, and I-- I took off through the thorns, chest high, ... Quote Link to comment
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