Scott Ellis, post: 383660, member: 7154 wrote: It would take too long, cost too much, these companies aren't neophytes, they understand what it costs to survey, and if they see something way out of line they will quickly get rid of you.
Imagine 260 section corner spread through 5 townships and you are going to static them?
PPK maybe as a check, ok,But static?
How long of an occupation would we be talking about, nearest CORS is 90 miles.
For what benefit?
If I feel I need to setup and run a static on a point I will, I also do not let my clients set the price of my work. The benefit would be knowing my work is correct.
Scott, I understand your position, and I will also use static when I feel it's needed,
But this wasn't the job for static sessions, there was no benefit for it, IMO.
You may differ with that assessment, but I do know there was a limit to costs for what was being done, and I feel the company doing the work did it very well.
I also know without RTK you couldn't do the work (section locations were just a small part), there was too much to do.
As far as knowing your work is correct that isn't exclusive to static measurments
Scott Ellis, post: 383639, member: 7154 wrote: Could you explain to me why someone would get fired for using Static?
IKR?
Kent would've been fired a looooong time ago...LOL
:rofl:
Lee D, post: 383658, member: 7971 wrote: RTK is far more accurate than a total station if you have to traverse any distance at all. RTK is far more accurate than a total station if you can't avoid short backsights. RTK is far more accurate than a total station if a traverse is down a highly linear corridor. And yes speed does matter... we're in business to make money.
Along a conventional traverse with a total station, it isn't any trick at all to beat the RTK accuracy specs just by adding ties to control points via RapidStatic GPS vectors at intervals. What you end up with by trying to do it all with RTK is crappy local accuracy and crappy vertical accuracy that will not be typically present in a conventional traverse controlled by GPS vectors.
Apparently you discovered a point of diminishing returns in increasing your total station accuracy. At some point practicality caused you to select a tool that wasn't the most accurate but was suitable to the purposes you required of it. What were the practical implications? Likely price. I'm guessing you bought a relatively inexpensive total station over more precise (and consequently more expensive) total stations because the improvement in accuracy had not practical benefit to you. Somewhere practicality enters the equation and you've yet to state what practical difference it makes to most cadastral surveyors to choose the arguably more accurate static solution over the inarguably faster RTK solution. Will the difference in 3mm (static) and 8mm (RTK) be of any consequence to anyone?
RADAR, post: 383663, member: 413 wrote:
Kent would've been fired a looooong time ago...LOL
The great thing about being self-employed is you get to do what is right, not what somebody in the office tells you to do. Even L1 Rapid Static GPS vectors only require occupations between five and twenty minutes over typical land survey distances under a few miles between base and rover. Shawn has already mentioned that he has discovered that he needs RTK occupations of about four minutes to get a result that will allow him to sleep at night.
Kent McMillan, post: 383664, member: 3 wrote: Along a conventional traverse with a total station, it isn't any trick at all to beat the RTK accuracy specs just by adding ties to control points via RapidStatic GPS vectors at intervals. What you end up with by trying to do it all with RTK is crappy local accuracy and crappy vertical accuracy that will not be typically present in a conventional traverse controlled by GPS vectors.
That's just flat out not true. As plenty of people have said, a crappy surveyor can do a crappy survey with any piece of equipment you choose.
The reality is that it's entirely possible to do a very good survey with RTK, that any drop off in accuracy is not significant enough to matter, and that the time savings are definitely significant enough to outweigh any (perceived) shortcomings of the methodology. Sure, you can traverse 22,000' one way between static pairs, tie into additional static pairs every so often, and adjust it all out in StarNet. You might even be able to do all of that in a couple of days. And if you get it right and don't have any blunders or significant systematic biases you'll get coordinates from StarNet that are accurate to some statistical prediction. In the meantime, I'll go out with my RTK, get coordinates that are within 0.02' of yours (assuming yours are any good), and have three more jobs under my belt while you're still fiddle-farting around. I'll have error estimates on my vectors at 95% confidence, and I'll have weighted mean solutions with deviations from independent observations.
These specious arguments against RTK are tiresome. If someone does poor work, that's not their equipment's fault. RTK is probably the single greatest thing that ever happened to surveyors, with the possible exception of CADD.
Kent McMillan, post: 383666, member: 3 wrote: Even L1 Rapid Static GPS vectors only require occupations between five and twenty minutes over typical land survey distances under a few miles between base and rover.
If you believe that L1 only solutions from rapid static sessions under 20 minutes are more accurate than RTK then you really are delusional.
Shawn Billings, post: 383665, member: 6521 wrote: Will the difference in 3mm (static) and 8mm (RTK) be of any consequence to anyone?
Actually, that +/-8mm RTK RMS uncertainty that the manufacturers quote is under optimal conditions and surely can as easily go way South of that when you consider that the occupations will be in the suboptimal conditions that the real world presents. As a rule, the best results will always be from using GPS-derived positions in clean settings and connecting them with conventional measurements to tie the various non-GPSable features that are always present and to be located.
Lee D, post: 383668, member: 7971 wrote: If you believe that L1 only solutions from rapid static sessions under 20 minutes are more accurate than RTK then you really are delusional.
Actually, the beauty of experience and testing GPS vectors by combining them with conventional measurements is that one doesn't have to guess. The RTK uncertainty of +/-8mm is not a very tight result compared to L1 GPS on vectors under a couple of miles in length.
Lee D, post: 383667, member: 7971 wrote: The reality is that it's entirely possible to do a very good survey with RTK, that any drop off in accuracy is not significant enough to matter, and that the time savings are definitely significant enough to outweigh any (perceived) shortcomings of the methodology. Sure, you can traverse 22,000' one way between static pairs, tie into additional static pairs every so often, and adjust it all out in StarNet. You might even be able to do all of that in a couple of days. And if you get it right and don't have any blunders or significant systematic biases you'll get coordinates from StarNet that are accurate to some statistical prediction. In the meantime, I'll go out with my RTK, get coordinates that are within 0.02' of yours (assuming yours are any good), and have three more jobs under my belt while you're still fiddle-farting around. I'll have error estimates on my vectors at 95% confidence, and I'll have weighted mean solutions with deviations from independent observations.
The reality, though, is that you are very seldom going to have jobs where everything is RTKable. So you're going to have to break out the total station at some point just to locate perhaps at least 40% or more of the points positioned on a typical land survey (in Central Texas). I'm actually fairly familiar with dealing with single-base RTK uncertainties since they are very similar to PPK, i.e on the order of +/-1cm RMS horizontal and +/-2cm vertical, and I know what a sloppy result they produce compared to what you end up with after combining them with conventional measurements.
There are a hundred excuses for doing substandard work and wanting to cut costs is about as good as any of them.
Clearly, the distinction between substandard and past the point of diminishing returns is one that's entirely lost on you.
Maybe some day I'll have the luxury to survey purely for the sake of enjoyment. For now I'm going to do work that is as good as or better than the standards that are required by my employers and, more importantly, our clients, in the most efficient and profitable manner I can find.
Just as clearly you enjoy the argument and apparently derive some pleasure from aggravating people, and that's fine too.
It's rare that I have work that isn't completely RTKable
But then I live in the big open, big country, big PLSS
Most of our work can be done with RTK. Our guys have probably been guilty at times of trying to push it into places where they should have used a total station. We have standards for what we use it on and what methodology we use, and I try to ensure that they're adhered to. We really don't do that much boundary work, and when we do it really isn't going to matter if our coordinate is to the center of the 3/8" rebar or 0.02' to one side of the center.
Lee D, post: 383675, member: 7971 wrote: Clearly, the distinction between substandard and past the point of diminishing returns is one that's entirely lost on you.
No. when one is certifying compliance with an accuracy standard such as, say, the ALTA/NSPS specification provides, it simply isn't good enough to say in effect that "Well, I'd already spent more time on this job than my employer had estimated, so this will have to do."
Diminishing returns is a measure of efficient use of particular technology. If a standard can't be easily met by that technology, it would be incorrect to say that it had passed "the point of diminishing returns".
Maybe some day I'll have the luxury to survey purely for the sake of enjoyment. For now I'm going to do work that is as good as or better than the standards that are required by my employers and, more importantly, our clients, in the most efficient and profitable manner I can find.
Many states probably have very relaxed standards of practice or none at all. I'm sure that there are areas in the rural South where +/-0.5 ft. would be thought excessively meticulous. I'm used to working in an area where land values are relatively high and where the rural fringes are rapidly urbanizing, so I've developed methods that produce results appropriate to those facts. I'm sure that the survey factories that are more interested in a steady throughput of survey products would be working to different expectations.
Kent McMillan, post: 383679, member: 3 wrote: No. when one is certifying compliance with an accuracy standard such as, say, the ALTA/NSPS specification provides, it simply isn't good enough to say in effect that "Well, I'd already spent more time on this job than my employer had estimated, so this will have to do."
Obviously, it goes without saying that when you certify that a survey is to a certain standard, you have to take the time and use whatever methodology ensures that you have verifiably met that standard. No one has suggested otherwise.
Kent McMillan, post: 383679, member: 3 wrote: Many states probably have very relaxed standards of practice or none at all. I'm sure that there are areas in the rural South where +/-0.5 ft. would be thought excessively meticulous.
I'm sure that there are rural areas throughout the United States where +/-0.5' would meet the minimum standard for the type of survey being performed in the area that it's being done.
MightyMoe, post: 383676, member: 700 wrote: It's rare that I have work that isn't completely RTKable
Yes, in the parts of West Texas with wide open sky, it's remarkably easy to locate things without breaking a sweat. The exceptions are probably boundary markers up against 8 ft. tall game fences and bearing trees or bearings to topo objects, both of which usually require breaking out the total station. When you factor in the permanently rural character of the land use and low value of the land, if it weren't so easy to do better, +/-1cm would seem overkill.
If you want to say that RTK isn't good enough for what you do because of this reason or that reason, that's all well and good - that's your decision to make. But to suggest that everyone who uses RTK does so in order to turn out a high volume of shoddy work is an insult to everyone in the profession.
Lee D, post: 383680, member: 7971 wrote: I'm sure that there are rural areas throughout the United States where +/-0.5' would meet the minimum standard for the type of survey being performed in the area that it's being done.
Actually, in the most valuable urban lands of Arkansas, errors of +/-0.25 ft. would be fine. For rural lands, +/-0.75 ft. is acceptable. That's more of a lifestyle choice, though.
Lee D, post: 383682, member: 7971 wrote: If you want to say that RTK isn't good enough for what you do because of this reason or that reason, that's all well and good - that's your decision to make. But to suggest that everyone who uses RTK does so in order to turn out a high volume of shoddy work is an insult to everyone in the profession.
Actually, what I posted was that RTK users choose RTK because it is fast, not because it is the most accurate positioning method available. That should be abundantly clear. Where RTK becomes problematic is when (a) the user uses it as a high-reliability positioning method, but in a setting where it isn't or (b) fails to recognize the effects of the uncertainties in RTK-derived postiions and how they effect the accuracies of the courses and distances calculated from them. Both are easily avoided, but not if one is trying to set a land speed record for surveying.
Kent McMillan, post: 383684, member: 3 wrote: Actually, what I posted was that RTK users choose RTK because it is fast, not because it is the most accurate positioning method available. That should be abundantly clear. Where RTK becomes problematic is when (a) the user uses it as a high-reliability positioning method, but in a setting where it isn't or (b) fails to recognize the effects of the uncertainties in RTK-derived postiions and how they effect the accuracies of the courses and distances calculated from them. Both are easily avoided, but not if one is trying to set a land speed record for surveying.
I love it when we argue to a consensus, like this! Have a great day. I know I will. This is what I have been saying all along. And, the Javad Gear makes this easier. STILL TAKES TIME.
Nate