Kerry.

Really a good trades person never blames their tools . Half the problem in some cases is an over expectation of what the system is reliably capable of and understanding just how to make the most of what it does provide. Anders called it practice but experience is possibly another term. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Something that's not a myth is the amount of $$'s so far expended on WAAS with an awful amount of $$'s still to be spent and really one has to wonder what this amount of $$'s have really done US$11 billion for GPS and provides a service to the whole world, US$5-6 billion so far for WAAS and only covers a very limited part of the world. There just doesn't appear to be a six billion dollar improvement (yet) in many respects. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Something that's not a myth is the amount of $$'s so far expended on WAAS with an awful amount of $$'s still to be spent and really one has to wonder what this amount of $$'s have really done US$11 billion for GPS and provides a service to the whole world, US$5-6 billion so far for WAAS and only covers a very limited part of the world. There just doesn't appear to be a six billion dollar improvement (yet) in many respects. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Kodak's4:One thing that surprised me was that the unit seemed to be indicating that it was using the WAAS satellite in generating the fix. I was under the impression that the geosynch WAAS sats provided only correction data but perhaps that's not so. Anyone know for sure? The WAAS geo's can/are used directly in the position solution if the navigation message allows it. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Kodak's4:One thing that surprised me was that the unit seemed to be indicating that it was using the WAAS satellite in generating the fix. I was under the impression that the geosynch WAAS sats provided only correction data but perhaps that's not so. Anyone know for sure? The WAAS geo's can/are used directly in the position solution if the navigation message allows it. Cheers, Kerry. I never get lost everybody keeps telling me where to go

The elevation displayed by most recreational GPSr's is only approximate and basically does nothing with things like GoTo etc. Cheers, Kerry. I never get lost everybody keeps telling me where to go

The elevation displayed by most recreational GPSr's is only approximate and basically does nothing with things like GoTo etc. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Time of day does matter but then there's a few other variables that can/could all add up to decrease things at times. Fairly easy to see if it's purely the constellation without taking into account of obstructions etc. If you've got an approx location, time of day (either local time/offset or preferably UTC time) and date one can look at what should be in view and the conditions at the time. That ignoring obstructions but if there's mountains, trees etc then some idea of them can be included in the solution as well. If you can supply that info then I'll give you some answers. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Time of day does matter but then there's a few other variables that can/could all add up to decrease things at times. Fairly easy to see if it's purely the constellation without taking into account of obstructions etc. If you've got an approx location, time of day (either local time/offset or preferably UTC time) and date one can look at what should be in view and the conditions at the time. That ignoring obstructions but if there's mountains, trees etc then some idea of them can be included in the solution as well. If you can supply that info then I'll give you some answers. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Any time isn't always the best time as certain times are better then other times. Or in other words TIME of day does matter but only in technical terms. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Any time isn't always the best time as certain times are better then other times. Or in other words TIME of day does matter but only in technical terms. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Basically the system controls the primary accuracy and the user controls (affects) the rest. It's not so much the recievers problem as much as the users understanding of how to make the most from what the system provides. As for Multipath there would be very few users using recreational equipment who could detect properly if multipath was a contributing factor or not. 300 feet does sound more like a user issue with either datum and/or position format. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Basically the system controls the primary accuracy and the user controls (affects) the rest. It's not so much the recievers problem as much as the users understanding of how to make the most from what the system provides. As for Multipath there would be very few users using recreational equipment who could detect properly if multipath was a contributing factor or not. 300 feet does sound more like a user issue with either datum and/or position format. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Be there at the best time of day ( and not a word about averaging ) Cheers, Kerry. I never get lost everybody keeps telling me where to go

Be there at the best time of day ( and not a word about averaging ) Cheers, Kerry. I never get lost everybody keeps telling me where to go

WIthout any type of offsetting system the position is always technically the L1 (electrical) centre of the actual antenna. Cheers, Kerry. I never get lost everybody keeps telling me where to go

WIthout any type of offsetting system the position is always technically the L1 (electrical) centre of the actual antenna. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Waterboy, Really what this has highlighted is the precision (or is the lack of ) that depending on the software/hardware available we are restricted to. With reference to your point 1. 3 metres (or 0.001') is about all most recreational GPSr's are good for. Those coordinates to 3 decimal of a metre (1mm) are exactly that less than 1mm but no normal GPSr's would be able to determine that. 2. equations rather long and something a simple calulator simply doesn't/can't handle and are quite extensive. And really for all purposes here the precision is fine but in reality the "actual" UTM coordinates of N42 36.392000' W078 00.160000' are 745870.320mE, 4721478.212mN and N42 34.718' W077 58.448' are 255923.968mE, 4718312.628mN so what appears identical is normally not really identical but the best a particlar system can do. As mentioned previosly both Lat/Long and UTM are both derived from a higher native position format and really both can/will give the same results taking into account coordinate precision, rounding and all that type of stuff. Much like saying what's the direction bewteen 2 points , is that a true bearing, a grid bearing or do they mean an azimuth , similar with distance, Spheroidal, Grid or Plane all of which can be derived from either type of coordinate format and relative to the precision of the available coordinates. Of course not all that important with Geocaching unless one wnats to specificy either end of a match (as well as a dozen separate points in between) Cheers, Kerry. I never get lost everybody keeps telling me where to go

Waterboy, Really what this has highlighted is the precision (or is the lack of ) that depending on the software/hardware available we are restricted to. With reference to your point 1. 3 metres (or 0.001') is about all most recreational GPSr's are good for. Those coordinates to 3 decimal of a metre (1mm) are exactly that less than 1mm but no normal GPSr's would be able to determine that. 2. equations rather long and something a simple calulator simply doesn't/can't handle and are quite extensive. And really for all purposes here the precision is fine but in reality the "actual" UTM coordinates of N42 36.392000' W078 00.160000' are 745870.320mE, 4721478.212mN and N42 34.718' W077 58.448' are 255923.968mE, 4718312.628mN so what appears identical is normally not really identical but the best a particlar system can do. As mentioned previosly both Lat/Long and UTM are both derived from a higher native position format and really both can/will give the same results taking into account coordinate precision, rounding and all that type of stuff. Much like saying what's the direction bewteen 2 points , is that a true bearing, a grid bearing or do they mean an azimuth , similar with distance, Spheroidal, Grid or Plane all of which can be derived from either type of coordinate format and relative to the precision of the available coordinates. Of course not all that important with Geocaching unless one wnats to specificy either end of a match (as well as a dozen separate points in between) Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Waterboy:For those cachers who believe in UTM: Please calculate the distances between these two caches: 17 T 745870 4721477 18 T 255924 4718312 You may use paper, your head, or a simple calculator. (Calculator may have trig functions.) This must be done without converting to Latitude and Longitude. For the cachers who believe in Lat/Lon: Please calculate the distances between these two caches: N 42° 36.392 W 078° 00.160 N 42° 34.718 W 077° 58.448 You may use paper, your head, or a simple calculator. (Calculator may have trig functions.) This must be done without converting to UTM. The two caches actually exist. Datum (assume WGS84 ) and to what type of precision Head, paper or "simple calculator" no matter what way one looks at positions like this in general the result is always going to be a "bit rough", because no one is going to come with something like 3884.401m or 3884.607m and expect somebody to believe "that's it" 3 decimal places and all based on coords to 1m and minutes to 3 decimals etc. Anyway they are presumably the same points with some human "rounding" limitations. Even these 2 points have some rounding issues but then are they 2 points or the same point 17 T 745870.000 4721477.000 18 T 253691.750 4721492.548 Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Waterboy:For those cachers who believe in UTM: Please calculate the distances between these two caches: 17 T 745870 4721477 18 T 255924 4718312 You may use paper, your head, or a simple calculator. (Calculator may have trig functions.) This must be done without converting to Latitude and Longitude. For the cachers who believe in Lat/Lon: Please calculate the distances between these two caches: N 42° 36.392 W 078° 00.160 N 42° 34.718 W 077° 58.448 You may use paper, your head, or a simple calculator. (Calculator may have trig functions.) This must be done without converting to UTM. The two caches actually exist. Datum (assume WGS84 ) and to what type of precision Head, paper or "simple calculator" no matter what way one looks at positions like this in general the result is always going to be a "bit rough", because no one is going to come with something like 3884.401m or 3884.607m and expect somebody to believe "that's it" 3 decimal places and all based on coords to 1m and minutes to 3 decimals etc. Anyway they are presumably the same points with some human "rounding" limitations. Even these 2 points have some rounding issues but then are they 2 points or the same point 17 T 745870.000 4721477.000 18 T 253691.750 4721492.548 Cheers, Kerry. I never get lost everybody keeps telling me where to go

If there's a requirement for a pref option then the underlining coordinate system should be earth centred cartesian . At least that's something that's unique from which ALL other "things" are derived. But basically all have some form of disadvantage, even UTM having that added zone variable and especially when zone to zone transformations or zone overlaps are concerned. It what one gets "more used to" that appears "more friendly" but really they all have some down sides. Cheers, Kerry. I never get lost everybody keeps telling me where to go

If there's a requirement for a pref option then the underlining coordinate system should be earth centred cartesian . At least that's something that's unique from which ALL other "things" are derived. But basically all have some form of disadvantage, even UTM having that added zone variable and especially when zone to zone transformations or zone overlaps are concerned. It what one gets "more used to" that appears "more friendly" but really they all have some down sides. Cheers, Kerry. I never get lost everybody keeps telling me where to go

They've got the story a little wrong saying it will be on the same frequency as GPS. It will be "compatible" with GPS but that's not the same as being on the same frequency. Similar with GLONASS, has been made to function in conjunction with GPS but different freq's again. In either case increased accuracy will cost. Cheers, Kerry. I never get lost everybody keeps telling me where to go

They've got the story a little wrong saying it will be on the same frequency as GPS. It will be "compatible" with GPS but that's not the same as being on the same frequency. Similar with GLONASS, has been made to function in conjunction with GPS but different freq's again. In either case increased accuracy will cost. Cheers, Kerry. I never get lost everybody keeps telling me where to go