Kerry.

The real praise must go to the underground survey work as without that it really didn't matter what type of gear one had on the surface. GPS was only a very minor part in this effort, the credit must go to the underground survey work (and GPS certainly doesn't work underground). Basically using $60,000 work of gear to locate workings surveyed with conventional survey gear and probably measuring tapes. It was only ever going to be as good as the U/G surveys. Cheers, Kerry. I never get lost everybody keeps telling me where to go

The real praise must go to the underground survey work as without that it really didn't matter what type of gear one had on the surface. GPS was only a very minor part in this effort, the credit must go to the underground survey work (and GPS certainly doesn't work underground). Basically using $60,000 work of gear to locate workings surveyed with conventional survey gear and probably measuring tapes. It was only ever going to be as good as the U/G surveys. Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Justin Sane:OK, so I'm an idiot. I realized that when I was inputting the coords on my mapping software, I wasn't using the proper format. It called for decimal format, but I was putting in degrees/minutes. It accepted my input, but I didn't realize that the numbers were different. So I went into my GPSr (eTrex Venture for those interested), changed the format to decimal, reinput those numbers into the mapping software, and it was dead solid on my house. So, instead of a massive government conspiracy worthy of Moulder and Scully, it was simply a lone gunman shooting mental blanks. Put it in the 'Duh' file. Don't worry, ya not the first. The following all based on real world examples like you've found http://www.cqnet.com.au/~user/aitken/gps/format.htm Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Justin Sane:OK, so I'm an idiot. I realized that when I was inputting the coords on my mapping software, I wasn't using the proper format. It called for decimal format, but I was putting in degrees/minutes. It accepted my input, but I didn't realize that the numbers were different. So I went into my GPSr (eTrex Venture for those interested), changed the format to decimal, reinput those numbers into the mapping software, and it was dead solid on my house. So, instead of a massive government conspiracy worthy of Moulder and Scully, it was simply a lone gunman shooting mental blanks. Put it in the 'Duh' file. Don't worry, ya not the first. The following all based on real world examples like you've found http://www.cqnet.com.au/~user/aitken/gps/format.htm Cheers, Kerry. I never get lost everybody keeps telling me where to go

now are we 100% sure we are 100% sure But for sure the timing is one of the critical things but then a few other "things" can affect that as well and that's what we are never quite sure about. Actually a month or so ago there were some "anomolies" that were detected in the system, which have apparently been there since the early 80's but due to operational circumstances had never been detected before. Now been fixed but for a few days the ranging errors were in the order of +/- 16 metres but the user performance was still within specifications. That unknown 5% (95% confidence) obviously comes in handy at times for these man made/run/operated systems. That I'm 100% sure of BP, that "reductionist" conclusion could be a possibility but being a software function the displayed estimated accuracy could be tuned in different ways. At the other end of the scale outside the WAAS ground network a WAAS receiver does know it has got a problem but again it doesn't appear to show ALL the error that actually exists. Really estimates of the position error appear to fluctuate around the middle values and not the upper and lower limits (maybe they're not 100% sure ). Cheers, Kerry. I never get lost everybody keeps telling me where to go

now are we 100% sure we are 100% sure But for sure the timing is one of the critical things but then a few other "things" can affect that as well and that's what we are never quite sure about. Actually a month or so ago there were some "anomolies" that were detected in the system, which have apparently been there since the early 80's but due to operational circumstances had never been detected before. Now been fixed but for a few days the ranging errors were in the order of +/- 16 metres but the user performance was still within specifications. That unknown 5% (95% confidence) obviously comes in handy at times for these man made/run/operated systems. That I'm 100% sure of BP, that "reductionist" conclusion could be a possibility but being a software function the displayed estimated accuracy could be tuned in different ways. At the other end of the scale outside the WAAS ground network a WAAS receiver does know it has got a problem but again it doesn't appear to show ALL the error that actually exists. Really estimates of the position error appear to fluctuate around the middle values and not the upper and lower limits (maybe they're not 100% sure ). Cheers, Kerry. I never get lost everybody keeps telling me where to go

Gliderguy, I think what sort of slowed WAAS down a little was the setting to zero of SA and the $$$'s that were steadily and steadily building. At this point in time most countries simply couldn't afford or justify a WADGPS (WAAS) type system but still not a wheels on the ground type landing system in any weather as that where LAAS sort of fits in. The reporting of those errors considering the time frame they need to be reported in is a critical component with WAAS (still to be solved in some instances). I suppose WAAS is WAAS but as it's implemented in most handheld type receivers is rather a little different to the full capability of the system as far as error reporting and capability is concerned. For recreational type handhelds it's rather not an ideal type of system to even be bothering with at this point in time but some have seen the need to promote it as "the thing" (sometimes the only thing), which really it's not but as you say for aircraft that's a totally different story but for some reason developement has appeared to have slowed remarkedly in recent times? Cheers, Kerry. I never get lost everybody keeps telling me where to go

Gliderguy, I think what sort of slowed WAAS down a little was the setting to zero of SA and the $$$'s that were steadily and steadily building. At this point in time most countries simply couldn't afford or justify a WADGPS (WAAS) type system but still not a wheels on the ground type landing system in any weather as that where LAAS sort of fits in. The reporting of those errors considering the time frame they need to be reported in is a critical component with WAAS (still to be solved in some instances). I suppose WAAS is WAAS but as it's implemented in most handheld type receivers is rather a little different to the full capability of the system as far as error reporting and capability is concerned. For recreational type handhelds it's rather not an ideal type of system to even be bothering with at this point in time but some have seen the need to promote it as "the thing" (sometimes the only thing), which really it's not but as you say for aircraft that's a totally different story but for some reason developement has appeared to have slowed remarkedly in recent times? Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Anders: quote:Originally posted by Kerry: Anders called it practice but experience is possibly another term. Well, Kerry, practice eventually leads to experience... Anders So does that mean the experienced should practice first Cheers, Kerry. I never get lost everybody keeps telling me where to go

quote:Originally posted by Anders: quote:Originally posted by Kerry: Anders called it practice but experience is possibly another term. Well, Kerry, practice eventually leads to experience... Anders So does that mean the experienced should practice first Cheers, Kerry. I never get lost everybody keeps telling me where to go

EraSeek, in no specific order but as I'm reading things. "Give the system credit" I give the system all the credit in the world but I also realize that one can only generally get a result as good as the information that goes into that result. All recreational output is based on predicted data from single frequency receivers and modeled atmospherics (plus a few other things). Basically knowing what the signal-in-space (SIS) errors, then the affects of atmospherics and the user influences I really don't get all that impressed about accuracy claims that can't be quantified relative to the system specifications. "2 metres, 1 metres away" well some of the time it could be (it is in fact) but would one risk it being that all the time, no way. "Work in the industry" no I don't "work" in the industry as such but I do make use of the system basically like many others but just at varying levels of accuracy (depending). Been finding things for years actually but no not in terms of what you refer but then I really didn't think "no finds" had all that much to do with GPS discussions. Precision is a funny things and really is not related to accuracy as both can be/and can not be related. Just because the position displays umpteenth number of decimals doesn't mean it's precise (or for some accurate but I don't want to get into that). At the end of the day the system controls the accuracy (generally) apart from things (methods) that can circumvent and cancel out the problematic and systematic errors. GPS is certainly an aid and the depth of that aid differs depending on the approach taken in utilizing this aid (GPS). To some 10 metres is enough and for that is costs X amount, to others sub millimetre is required and that costs $$$$'s and specific methods to achieve that result but at the end of the day there's no such thing as a zero error measurement system (not to this point in time anyway). Really the system has very well defined specifications but for obvious reasons manufacturers (especially in pre SA days) defined accuracy that might have sounded a lot better but in fact wasn't. Probably still applies today? Which would you buy? something with an accuracy of "less than 13m @ 95% SIS"? or "less than 3m CEP"? is there a difference? For far too long there's been too many myths perpetrated and especially about things like accuracy, # of channels, averaging etc etc. Cheers, Kerry. I never get lost everybody keeps telling me where to go

EraSeek, in no specific order but as I'm reading things. "Give the system credit" I give the system all the credit in the world but I also realize that one can only generally get a result as good as the information that goes into that result. All recreational output is based on predicted data from single frequency receivers and modeled atmospherics (plus a few other things). Basically knowing what the signal-in-space (SIS) errors, then the affects of atmospherics and the user influences I really don't get all that impressed about accuracy claims that can't be quantified relative to the system specifications. "2 metres, 1 metres away" well some of the time it could be (it is in fact) but would one risk it being that all the time, no way. "Work in the industry" no I don't "work" in the industry as such but I do make use of the system basically like many others but just at varying levels of accuracy (depending). Been finding things for years actually but no not in terms of what you refer but then I really didn't think "no finds" had all that much to do with GPS discussions. Precision is a funny things and really is not related to accuracy as both can be/and can not be related. Just because the position displays umpteenth number of decimals doesn't mean it's precise (or for some accurate but I don't want to get into that). At the end of the day the system controls the accuracy (generally) apart from things (methods) that can circumvent and cancel out the problematic and systematic errors. GPS is certainly an aid and the depth of that aid differs depending on the approach taken in utilizing this aid (GPS). To some 10 metres is enough and for that is costs X amount, to others sub millimetre is required and that costs $$$$'s and specific methods to achieve that result but at the end of the day there's no such thing as a zero error measurement system (not to this point in time anyway). Really the system has very well defined specifications but for obvious reasons manufacturers (especially in pre SA days) defined accuracy that might have sounded a lot better but in fact wasn't. Probably still applies today? Which would you buy? something with an accuracy of "less than 13m @ 95% SIS"? or "less than 3m CEP"? is there a difference? For far too long there's been too many myths perpetrated and especially about things like accuracy, # of channels, averaging etc etc. Cheers, Kerry. I never get lost everybody keeps telling me where to go

It's possible that some situations might employ jammers (when required) but really we aren't going to to told about what there is and what there isn't. The system does have Selective Deniability (as far as we now) but just how selective again that's an unknown but most likely not isolated to a single facility. There's nothing to suggest at all that the system is responsible for selective 2km errors even though there's that presumption that 2km was a possibility under the old selective availability. As for WAAS the "Military Emergency Mode" is part of the WAAS system which the US Air Force can provoke at their own pergotative. The worse scenario could be the whole civilian side of the system could possibily be shutdown (that would obviously be a time to hide, real good) Cheers, Kerry. I never get lost everybody keeps telling me where to go

It's possible that some situations might employ jammers (when required) but really we aren't going to to told about what there is and what there isn't. The system does have Selective Deniability (as far as we now) but just how selective again that's an unknown but most likely not isolated to a single facility. There's nothing to suggest at all that the system is responsible for selective 2km errors even though there's that presumption that 2km was a possibility under the old selective availability. As for WAAS the "Military Emergency Mode" is part of the WAAS system which the US Air Force can provoke at their own pergotative. The worse scenario could be the whole civilian side of the system could possibily be shutdown (that would obviously be a time to hide, real good) Cheers, Kerry. I never get lost everybody keeps telling me where to go

GPS, yes but nothing one could compare with what the general "military system" is in general as that's certainly not good to 1cm by itself either. More like a real-time/differential system based on dual frequency and worth a few $$'s but still only as good as the people using it and understanding it. But at the end of the day what ever was used to locate the "surface" starting point was only ever going to be as good as the underground surveys and surveyors and in underground mines GPS doesn't work (at all) . So to the underground mine surveyors I say say well done (but that's their job anyway) but that's what miners rely on every day, someome telling them where to go and knowing where they are and where they are going. And when it's all said and done in situations such as this many might not realize what's has gone on in the background. GPS it's just another tool, and in this case it certainly wasn't the primary tool in knowing where to drill that (those) holes, it was a mine surveyor The only thing that shouldn't have occured in the first place is possibly drilling into old workings or unknown situations and that is a legacy (for many and varied reasons) of the past. Cheers, Kerry. I never get lost everybody keeps telling me where to go

GPS, yes but nothing one could compare with what the general "military system" is in general as that's certainly not good to 1cm by itself either. More like a real-time/differential system based on dual frequency and worth a few $$'s but still only as good as the people using it and understanding it. But at the end of the day what ever was used to locate the "surface" starting point was only ever going to be as good as the underground surveys and surveyors and in underground mines GPS doesn't work (at all) . So to the underground mine surveyors I say say well done (but that's their job anyway) but that's what miners rely on every day, someome telling them where to go and knowing where they are and where they are going. And when it's all said and done in situations such as this many might not realize what's has gone on in the background. GPS it's just another tool, and in this case it certainly wasn't the primary tool in knowing where to drill that (those) holes, it was a mine surveyor The only thing that shouldn't have occured in the first place is possibly drilling into old workings or unknown situations and that is a legacy (for many and varied reasons) of the past. Cheers, Kerry. I never get lost everybody keeps telling me where to go

EraSeek, And really the manufacturers should know better instead of providing this type of mythical information, which is totally not achievable with this type of equipment. Like the calclator syndrome all this type of stuff needs to be kept in perpective other wise new myths are born. Similar with WAAS it all needs to be put in perpective. Cheers, Kerry. I never get lost everybody keeps telling me where to go

EraSeek, And really the manufacturers should know better instead of providing this type of mythical information, which is totally not achievable with this type of equipment. Like the calclator syndrome all this type of stuff needs to be kept in perpective other wise new myths are born. Similar with WAAS it all needs to be put in perpective. Cheers, Kerry. I never get lost everybody keeps telling me where to go

As with any augmentation system (be it WAAS, DGPS etc) the intregrity is generally more important than the inprovement in accuracy. When Selective Availability was terminated it was fairly evident at that time that EPE (and similar) in many of the recreational recievers was a massaged figure. When actual accuracy improved by a factor od 7 and EPE only by a factor of 2 then somebody was kidding someone and probably still do. With no prior announcement manufacturers sort of got caught out on that one but prior to that they had some scope (< 100m @ 95%) to hide things but not anymore [< 13m @ 95% and even less than that in the real world). Also has me buggered how one can quote distances to 0.01 feet or even 0.1 feet from these types of receivers. Whose kidding who Same for relationships based on lats/longs to 3 decimal minutes as there can be around 8 feet floating around in them simply based on numbers without the affects of the real world. Cheers, Kerry. I never get lost everybody keeps telling me where to go

As with any augmentation system (be it WAAS, DGPS etc) the intregrity is generally more important than the inprovement in accuracy. When Selective Availability was terminated it was fairly evident at that time that EPE (and similar) in many of the recreational recievers was a massaged figure. When actual accuracy improved by a factor od 7 and EPE only by a factor of 2 then somebody was kidding someone and probably still do. With no prior announcement manufacturers sort of got caught out on that one but prior to that they had some scope (< 100m @ 95%) to hide things but not anymore [< 13m @ 95% and even less than that in the real world). Also has me buggered how one can quote distances to 0.01 feet or even 0.1 feet from these types of receivers. Whose kidding who Same for relationships based on lats/longs to 3 decimal minutes as there can be around 8 feet floating around in them simply based on numbers without the affects of the real world. Cheers, Kerry. I never get lost everybody keeps telling me where to go

The latest is 4.58 and since that is a few years old now I would very much doubt there will be any further changes or modifciations to that. Cheers, Kerry. I never get lost everybody keeps telling me where to go

The latest is 4.58 and since that is a few years old now I would very much doubt there will be any further changes or modifciations to that. Cheers, Kerry. I never get lost everybody keeps telling me where to go

Averaging these days is not all that it used to be prior to Selective Availability being set to zero. Probably more important these days is being at a certain place at the right time as satellite geometry (the DOP's) really controls the "expected" accuracy. Why more manufacturers don't provide some of the actual DOP's instead of their "manufacturered" and propriety estimates has me beat. Anyway as for averaging I don't believe it's all that usefull these days http://www.cqnet.com.au/~user/aitken/gps/gps_avg.htm and http://www.cqnet.com.au/~user/aitken/gps/gps_obs.htm Time of day does matter as does the effect of obstructions relative to that time of day. I've got a link to one of them too (when I find it ) Cheers, Kerry. I never get lost everybody keeps telling me where to go

Averaging these days is not all that it used to be prior to Selective Availability being set to zero. Probably more important these days is being at a certain place at the right time as satellite geometry (the DOP's) really controls the "expected" accuracy. Why more manufacturers don't provide some of the actual DOP's instead of their "manufacturered" and propriety estimates has me beat. Anyway as for averaging I don't believe it's all that usefull these days http://www.cqnet.com.au/~user/aitken/gps/gps_avg.htm and http://www.cqnet.com.au/~user/aitken/gps/gps_obs.htm Time of day does matter as does the effect of obstructions relative to that time of day. I've got a link to one of them too (when I find it ) Cheers, Kerry. I never get lost everybody keeps telling me where to go

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