Ridiculing standards?
Reduced to ridiuculing published standards?
As I understand it, a lot of the objection to RTK was that it was
a) Not of value to surveyors.
That got qualified to:
b) Not valuable for cadastral surveys
When it was pointed out that not all cadastral surveys require the same standards the objection was that it could
c) Not meet published standards
Then published standards were produced. Actual valid published standards.
Then those standards, and by extension the board of registration and surveyors who framed them and adhere to them were ridiculed.
Let's face, it, on that one you got owned.
When it is a short length, RTK/GNSS is a weak tool, Over long distances it shines, and saves a lot of time and costs. You can't tell me that doing a closed traverse over many km (sorry miles) over hill and dale is going to be the same cost as an RTK or static GNSS survey? Especially if the distance dependent error budget is fine for both. Have you every done both side by side? Back when a firm I worked for first used RTK we had to do them side by side. RTK was dramatically less costly and time consuming for what mathematically (over those distances) gave comparable results.
How is your experience with such comparisons? From reading recent posts it seems you do not use RTK and might not have experienced such time and cost savings.
Lets face it, on the cost thing you got owned.
Oh Canada (or is it "Oh Canada!", that's right. Just what was handy this morning:
NRCAN
General Instructions for Surveys, e-Edition
Chapter D1 - OFFICIAL SURVEYS
Effective Date:
This Chapter is effective April 1, 2008. It replaces Chapter D1 as published April 1, 2004 in the General Instructions for Surveys of Canada Lands, e-Edition.
Accuracy
53. The minimum accuracy standard for legal surveys is defined by the ellipse showing the 95% confidence region for the positioning of one station relative to another. The semi-major axis of this ellipse in centimetres (r) with respect to another station must be less than or equal to C( d+ 0.25) where:
C = an assigned value depending on the accuracy requirement; and
d = the distance in kilometres to any station.
54. For surveys involving the surveyor's own work, C is assigned the value 8. The following table illustrates how various distances affect the semi-major axis of the 95% confidence region of one station with respect to another, parts per million (ppm) and the accuracy ratio for r = 8( d+ 0.25):
d (km) r (cm) ppm ratio
0.01 2.1 2100 1/480
0.03 2.2 733 1/1360
0.10 2.8 280 1/3570
0.50 6.0 120 1/8033
1.00 10.0 100 1/10000
For surveys using the surveyor's own measurements combined with previous surveyors' measurements, C is assigned the value 15. The following table illustrates how various distances affect the semi-major axis of the 95% confidence region of one station with respect to another, parts per million (ppm) and the accuracy ratio for r = 15( d+ 0.25):
d (km) r (cm) ppm ratio
0.01 3.9 3900 1/260
0.03 4.2 1400 1/710
0.10 5.3 530 1/1890
0.50 11.3 225 1/4420
1.00 18.8 190 1/5320
If the accuracy for a connection, involving a previous surveyor's work does not meet legal survey standards, the connection shall be remeasured or verified using an independent method.
Got owned on that one too eh?
I can appreciate your concerns over slopply RTK surveyors, I hate to see that too. I also do not like survetors who do not close traverses, or do not check their instruments, or do not follow a lot of other good practices.
But when you start to ridicule published standards, that is weak.
Ridiculous Position on RTK
> As I understand it, a lot of the objection to RTK was that it was
>
> a) Not of value to surveyors.
Actually, that was your construction of the phrase "land surveyors" which in Texas means surveyors engaged in boundary surveying. That's "cadastral surveying" in Canada.
> That got qualified to:
> b) Not valuable for cadastral surveys
Actually, you asked what the value of RTK was, as if it had some inherent value independent of a user with some professional knowledge of its limitations. Without that second component of the system, RTK is in fact fairly worthless for cadastral surveys.
> When it was pointed out that not all cadastral surveys require the same standards the objection was that it could
> c) Not meet published standards
Actually, as I demonstrated days ago, RTK-derived positions that have uncertainties greater than certain threshold values do not meet the ALTA minimum positional accuracy standards. I trust that demonstration convinced anyone in doubt about the matter.
> Then published standards were produced. Actual valid published standards.
Oklahoma standards? LOL! Sorry, that and a nickel won't buy you anything. When you contract to perform a survey to a particular standard, such as the ALTA or Texas minimum standards, you want to show up waving the OKIE standards as proof that you weren't negligent? Please post the video of this. :>
> Then those standards, and by extension the board of registration and surveyors who framed them and adhere to them were ridiculed.
Yes, Oklahoma is a state that exists to provide a laugh for the rest of us as far as I can tell.
> Let's face, it, on that one you got owned.
I think you probably don't realize how far off track you've wandered. Why not just admit that the points I made should be obvious to any professional surveyor? They really should be.
> When it is a short length, RTK/GNSS is a weak tool, Over long distances it shines, and saves a lot of time and costs.
Actually, GPS works great. RTK is just a lower-grade method that many users like because it can be real fast.
>You can't tell me that doing a closed traverse over many km (sorry miles) over hill and dale is going to be the same cost as an RTK or static GNSS survey?
Huh? We use static and PPK GPS all the time, adjusted in combination with conventional measurements However, we use it in such a way that we can actually demonstrate the quality of positioning results, unlike the typical RTK user's work.
This discussion should be about how to use RTK properly and that begins with determining what the uncertainties in RTK-derived positions actually are, doesn't it? Yes, it does. If a particular method of using RTK doesn't meet a specification, then surely you aren't arguing that RTK should be used anyway, are you?
Ridiculous arguements about RTK
One persons meat is anothers posion.
Your objections are noted. Not totally invalid, not totally conclusive. A bit insulting to some surveyors and at least one state, I will not bnother to dig up more as you will just insult those.
I'll bet there is someone out there right now in your own state that is doing some land survey with RTK, maybe Cat 1-B, maybe doing the math to see if say 1:7500(+0.1') is met and probaly succeeding. Maybe many people. And they will not suddenly give up thier tools because someone else does not like them, or insults thier abilties, or gives them no credit for thier own judgement or ability ot meet standards.
Am I expecting to suddenly see thousands of RTK sets for sale online based on your objections? I do not think so.
Ridiculous arguements about RTK
> Your objections are noted. Not totally invalid, not totally conclusive.
Actually, the real problem is that most RTK users haven't even bothered to consider the problem of relative positional uncertainty in any but the most informal way.
That making the obvious observation that in some common situations there is a definite relative positional uncertainty problem with RTK causes many RTK-dependent posters such obvious grief tells me that this is something that they at least unconsciously recognize is a problem with their work. Otherwise, there would be plenty of good answers to the points I made that don't basically amount to "but it's good enough for Oklahoma!"
Diss-ing more standards?
Or good enough for, from a very quuick search, MO, KY, AR, SC, NC:
Care to insult those states too?
Missouri
10 CSR 30-2.040 Accuracy Standards for Property Boundary Surveys
Kentucky
10 CSR 30-2.040 Accuracy Standards for
Property Boundary Surveys
Arkansas
http://www.pels.arkansas.gov/rulesRegsStandards/Documents/standardsPractice.pdf
SC
http://www.llr.state.sc.us/pol/engineers/PDF_Files/Minimum%20Standards%20Manual.PDF
NC
21 NCAC 56 .1603 CLASSIFICATION OF BOUNDARY SURVEYS
There are better ways to lead people to water and get them to drink.
Diss-ing more standards?
> Arkansas
>> http://www.pels.arkansas.gov/rulesRegsStandards/Documents/standardsPractice.pdf
I'm afraid that I couldn't get past Arkansas I was laughing so hard. In Arkansas a relative positional error of 0.25 ft. is considered the threshold of competent practice for urban land! That is extremely sloppy by any rational standard, i.e. a standard that connects the accuracy of urban boundary surveys with actual intensive urban land uses.
In intensively developed central business districts where buildings costing tens of millions are to be built, even the ALTA specs would be too loose for the use. I love the fact that you're unable to defend RTK relative positional accuracy except by dipping into the rural Southern US for guidance on how close a shack should be to a lot line.
If you want to be serious, why not start with California's minimum technical standards and work your way down, instead of starting at the bottom of the barrel in the rural South?