Scary. We build a capability and come to rely on it. A lot of applications have been tied on to GPS without thought of backups. Robustness always takes a back seat to cost efficiency.
I'm good....as long as the sun and the stars stay where they are.:-)
... And we have most of our Trigonometrical Pillars in the UK but we'll need the sun and stars offshore ...
I sit at night and listen to the local fire/police/emergency chatter on the scanner. A good deal of calls in rural areas, while sporting a specific map page and address, also has geodetic data transferred to response by the emergency dispatch.
Without an active gps network and constellation, our structured society would quickly unravel and grind to a near halt.
I bet there's a whole generation of commercial pilots that can't even read a printed Jeppesen chart. Heck with "Zombie" Apocalypse...try the "No GPS" Apocalypse. And high dollar car theft would flourish without working LO-Jacks and OnStar.
This is why we need eLoran as a backup...but the US government doesn't seem to be taking any action on it.
Absent GPS, land surveying as a profession would have to return to its academic roots.
rfc, post: 371013, member: 8882 wrote: I'm good....as long as the sun and the stars stay where they are.:-)
Of course precise time is dependent on GPS as well. See: http://tf.nist.gov/time/commonviewgps.htm
Larry Scott, post: 371142, member: 8766 wrote: Absent GPS, land surveying as a profession would have to return to its academic roots.
I hope that never happens...
As surveyors we've endured centuries of bad press. Why is that back half of Mt. Denali not inside Denali National Park?..you guessed it.
And even with our best intentions, solar and astronomic rigors and calcs can only provide a rudimentary amount of accuracy. If the whole world looked to surveyors for accurate six and seven point geodetic precision with our optical instruments...it would be sadly disappointed.
For all our sakes, let's hope the constellation stays aloft for a while.
Prepare. Submit lots of shared OPUS solutions for use if GNSS is interrupted.
paden cash, post: 371162, member: 20 wrote: I hope that never happens...
As surveyors we've endured centuries of bad press. Why is that back half of Mt. Denali not inside Denali National Park?..you guessed it.
And even with our best intentions, solar and astronomic rigors and calcs can only provide a rudimentary amount of accuracy. If the whole world looked to surveyors for accurate six and seven point geodetic precision with our optical instruments...it would be sadly disappointed.
For all our sakes, let's hope the constellation stays aloft for a while.
Are you suggesting that the majority of blunders, pin cushions, and other surveying oddities, occurred because of less accurate instruments, rather than careless, or less than capable surveyors? I'd find that extraordinarily hard to believe. Where's the proof of that? I've read of incredibly accurate surveys done with instruments far more basic than GPS.
Some might say rather "if the whole world looked to surveyors for accurate six and seven point geodetic precision with the latest GPS button laden instruments...it would be sadly disappointed".
rfc, post: 371179, member: 8882 wrote: Are you suggesting that the majority of blunders, pin cushions, and other surveying oddities, occurred because of less accurate instruments, rather than careless, or less than capable surveyors?
Not at all. All I'm saying is that repeatable six and seven point geodetic locations without gps could not delivered to the public with the ease and speed with which most are accustomed.
And from my experience with the equipment that is most readily available to most of us; sub-meter work from solar or astronomic observation would be exceptional if not amazing.
I'm just reminded of the Everest survey. Its major issue(s) wasn't the survey. It was logistics: transportation, supply lines, communication. And slow repetitive calculation procedures. Not the measuring, (even with chain distances, engine divided 'great theodolites'), and not the results.
GeeOddMike, post: 371161, member: 677 wrote: Of course precise time is dependent on GPS as well. See: http://tf.nist.gov/time/commonviewgps.htm
We had precise time long before GPS was created. If I'm not mistaken, USNO provides the clocks for the GPS system. GPS just makes accurate time much more widely available than it was in the past. And I believe you can get it from NIST too.
If the GPS system went down, I think a far greater disruption would be, not to positional information (surveyors would figure out how to do it again the way they did it in the past), but to accurate time. Power grids, cellular phone systems, many computer systems, rely on precise synchronization which if lost, fail outright.
Larry Scott, post: 371191, member: 8766 wrote: I'm just reminded of the Everest survey. Its major issue(s) wasn't the survey. It was logistics: transportation, supply lines, communication. And slow repetitive calculation procedures. Not the measuring, (even with chain distances, engine divided 'great theodolites'), and not the results.
And malaria...and tiger infested jungles. Some of that canopy would make GPS (even Javad, Nate :-)), useless. Of course they've pretty much nailed malaria, and most of the tigers have been killed, so you'd be able to do reeealy, reeeally long static sessions without fear of getting eaten.
In the mid 80s my company did a major survey, $80-90K several crews. 3 years later: GPS - a similar survey was $12K, one crew. Faster, cheaper, but not necessarily better.
If GPS went down, maybe we could finally quit arguing about 0.04' and at least argue about the gross error of 0.10'.........
rfc, post: 371196, member: 8882 wrote: And malaria...and tiger infested jungles. Some of that canopy would make GPS (even Javad, Nate :-)), useless. Of course they've pretty much nailed malaria, and most of the tigers have been killed, so you'd be able to do reeealy, reeeally long static sessions without fear of getting eaten.
Deploy a bunch of receivers all at once. It's be over in a week.
