Kerry.

There's no consistent relationship between NAD27 and the real world, which is why some GPS manufacturers have to implement many "different" NAD27 datums (most Garmins have for instance 11 "different" NAD27 options) depending on the location. There's also no common set of conversion parameters which fit the bill which is why distortion models are used in most conversions these days. Hopefully in due course ALL maps/charts will be in one uniform based datum and they won't be anything as ancient or outdated (or inaccurate) as NAD27. Cheers, Kerry. I never get lost everybody keeps telling me where to go

There's no consistent relationship between NAD27 and the real world, which is why some GPS manufacturers have to implement many "different" NAD27 datums (most Garmins have for instance 11 "different" NAD27 options) depending on the location. There's also no common set of conversion parameters which fit the bill which is why distortion models are used in most conversions these days. Hopefully in due course ALL maps/charts will be in one uniform based datum and they won't be anything as ancient or outdated (or inaccurate) as NAD27. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Planning to be at location when conditions are most favourable will give a position much more reliability and confidence rather than any averaging because as someone has already mentioned averaging bad data will only produce a bad average. Sometimes not always possible to plan ahead but at least one then knows when is the best (better) times to be at a certain location and just as important (sometimes even more so) when it's not. Maybe a simple planning package is something the site could look into providing? Most packages unfortuneately are not freeware and one also requires a regular updated almanac (generally on a daily basis is usefull). Cheers, Kerry. I never get lost everybody keeps telling me where to go

Planning to be at location when conditions are most favourable will give a position much more reliability and confidence rather than any averaging because as someone has already mentioned averaging bad data will only produce a bad average. Sometimes not always possible to plan ahead but at least one then knows when is the best (better) times to be at a certain location and just as important (sometimes even more so) when it's not. Maybe a simple planning package is something the site could look into providing? Most packages unfortuneately are not freeware and one also requires a regular updated almanac (generally on a daily basis is usefull). Cheers, Kerry. I never get lost everybody keeps telling me where to go

Why would one want averaging for anyway Cheers, Kerry. I never get lost everybody keeps telling me where to go

Why would one want averaging for anyway Cheers, Kerry. I never get lost everybody keeps telling me where to go

Circuitry wise, very little to non existent. Just about everything that affects GPS accuracy these days are on the outside not the inside and most of these are untouchables. Accuracy by far is much more dependent on Satellite clock stability, Emphemeris prediction models, Ionospheric noise, Tropospheric delay, Multipath and Noise all of which we really have no control over. Basically in terms of accuracy, all handheld GPS receivers are created equal. That have the same basic parts and use the same signals. It's what they do with what they get that makes the difference but the software is also an untouchable. As for the clock in a GPS it does not much more than tell the time where as the timing is something totally different and also basically untouchable. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Circuitry wise, very little to non existent. Just about everything that affects GPS accuracy these days are on the outside not the inside and most of these are untouchables. Accuracy by far is much more dependent on Satellite clock stability, Emphemeris prediction models, Ionospheric noise, Tropospheric delay, Multipath and Noise all of which we really have no control over. Basically in terms of accuracy, all handheld GPS receivers are created equal. That have the same basic parts and use the same signals. It's what they do with what they get that makes the difference but the software is also an untouchable. As for the clock in a GPS it does not much more than tell the time where as the timing is something totally different and also basically untouchable. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Many of the external antenna's have magnetic mount base options and there's no problems with them and it's the antenna and/or signal that would be subject to any magnetic effect if it existed. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Many of the external antenna's have magnetic mount base options and there's no problems with them and it's the antenna and/or signal that would be subject to any magnetic effect if it existed. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Not sure what type of accuracy you were expecting but 16 feet is well and truely with the system spec (13m @ 95% SIS) besides that figure is an Estimated Position Error (EPE) with the key word being "estimated". Cheers, Kerry. I never get lost everybody keeps telling me where to go

Not sure what type of accuracy you were expecting but 16 feet is well and truely with the system spec (13m @ 95% SIS) besides that figure is an Estimated Position Error (EPE) with the key word being "estimated". Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Cearnach: The reliability of WAAS should only get better, for the most part, between now and then. So that that does mean the system is not totally reliable now hence the need for the type 0 message (test mode) quote:Also, some of the satelites up there are not sending good data yet. So does that also mean the reliability (based on lack of "good" data) is also a reason for the test mode quote:They should soon though What is about to change soon Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Cearnach: The reliability of WAAS should only get better, for the most part, between now and then. So that that does mean the system is not totally reliable now hence the need for the type 0 message (test mode) quote:Also, some of the satelites up there are not sending good data yet. So does that also mean the reliability (based on lack of "good" data) is also a reason for the test mode quote:They should soon though What is about to change soon Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by CapnGadget: I have a basic yellow etrex...usually I walk about 50 - 100 yards from the cash, refix and walk back to the cache and take note of the co-ordinates...I do this 4 times to the cardinal points and then calculate the average and this is what I post. I don't think the system actually changes enough over time these days (without SA) for that to be entirely effective. Generally the relative accuracy between those cardinal points will be close but the overall absolute accuracy of all those points (to the intended location) will still be an unknown. The following is a practical real world example similar to what you describe and what some other users have previously nicknamed "golf ball averaging" everybody keeps telling me where to go

quote:Originally posted by CapnGadget: I have a basic yellow etrex...usually I walk about 50 - 100 yards from the cash, refix and walk back to the cache and take note of the co-ordinates...I do this 4 times to the cardinal points and then calculate the average and this is what I post. I don't think the system actually changes enough over time these days (without SA) for that to be entirely effective. Generally the relative accuracy between those cardinal points will be close but the overall absolute accuracy of all those points (to the intended location) will still be an unknown. The following is a practical real world example similar to what you describe and what some other users have previously nicknamed "golf ball averaging" everybody keeps telling me where to go

Well there's hope yet for several of my queries which by now must be well into 6 or 7 weeks old What no reply means I'm not sure but at this point in time I'm not calling it great technical support at all. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Well there's hope yet for several of my queries which by now must be well into 6 or 7 weeks old What no reply means I'm not sure but at this point in time I'm not calling it great technical support at all. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Prime Suspect: First off, WAAS is NOT broadcasting only "test signals". I suppose it depends on what one wants to use it for as WAAS is still broadcasting a Type 0 message and that is a Test mode. So in effect while that Type 0 message is being transmitted it effectively means they are not going to guarantee the accuracy, integrity, continuity or availability of the system for other than test mode purposes. The signal as available to the general community I believe still falls under the Type 0 test mode. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Prime Suspect: First off, WAAS is NOT broadcasting only "test signals". I suppose it depends on what one wants to use it for as WAAS is still broadcasting a Type 0 message and that is a Test mode. So in effect while that Type 0 message is being transmitted it effectively means they are not going to guarantee the accuracy, integrity, continuity or availability of the system for other than test mode purposes. The signal as available to the general community I believe still falls under the Type 0 test mode. Cheers, Kerry. I never get lost everybody keeps telling me where to go

12 sats means very little and besides the % of time this will occur is rather low. Also the number of Sats doesn't really equate to accuracy (as such) where as the geometry of the Sats do. Actually using all satellites available can be a detriment to accuracy especially when considering low on the horizon sats. However some manufacturers have made this 12 channel thing a selling point but in fact if they configured the receiver settings correctly there'd be no way anybody would (should) see 12 satellites. Cheers, Kerry. I never get lost everybody keeps telling me where to go

12 sats means very little and besides the % of time this will occur is rather low. Also the number of Sats doesn't really equate to accuracy (as such) where as the geometry of the Sats do. Actually using all satellites available can be a detriment to accuracy especially when considering low on the horizon sats. However some manufacturers have made this 12 channel thing a selling point but in fact if they configured the receiver settings correctly there'd be no way anybody would (should) see 12 satellites. Cheers, Kerry. I never get lost everybody keeps telling me where to go

So what does it do that's different Cheers, Kerry. I never get lost everybody keeps telling me where to go

So what does it do that's different Cheers, Kerry. I never get lost everybody keeps telling me where to go

More thoughts on Averaging Cheers, Kerry. I never get lost everybody keeps telling me where to go