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Getting started with Least Squares
Kent McMillan replied 8 years, 5 months ago 28 Members · 50 Replies
IN and KY standards refer to RPA, not RPP. I had this in mind when posting my questions above. It seems there may be a semantics issue here. A bit odd considering Gary Kent advises on the ALTA standards…you would think IN and ALTA would be more consistent with one another.
I agree that RPP is a better descriptor of the quantitative elements of a survey and RPA is more representative of a qualitative approach. Both important, nonetheless. Thanks for pointing that out.
Back to the question…How do you ensure that you are meeting the quantitative elements (RPP as you describe) required by the state or ALTA?
You said…
“I thought I had made it clear, I do not adjust my everyday field work. If it falls within my expectation of erros, I accept it for what it is. Honest measurements with error.“
I get this, and from what I’ve read in your posts, you seem to be a prudent and more than competent surveyor. I am not convinced that a savvy attorney and/or competent judge would accept that statement, however.
In my parts, there are guys who slap the “this survey meets the minimum state standards ….of an urban survey .07 +/- 50 ppm…” who have never ran LS and most certainly have never performed an independent survey of higher order.
I am concerned about the surveyor, not so prudent. That’s why the question arose.
IN and KY standards refer to RPA, not RPP. I had this in mind when posting my questions above. It seems there may be a semantics issue here. A bit odd considering Gary Kent advises on the ALTA standards…you would think IN and ALTA would be more consistent with one another.
I agree that RPP is a better descriptor of the quantitative elements of a survey and RPA is more representative of a qualitative approach. Both important, nonetheless. Thanks for pointing that out.
Back to the question…How do you ensure that you are meeting the quantitative elements (RPP as you describe) required by the state or ALTA?
You said…
“I thought I had made it clear, I do not adjust my everyday field work. If it falls within my expectation of erros, I accept it for what it is. Honest measurements with error.“
I get this, and from what I’ve read in your posts, you seem to be a prudent and more than competent surveyor. I am not convinced that a savvy attorney and/or competent judge would accept that statement, however.
In my parts, there are guys who slap the “this survey meets the minimum state standards ….of an urban survey .07 +/- 50 ppm…” who have never ran LS and most certainly have never performed an independent survey of higher order.
I am concerned about the surveyor, not so prudent. That’s why the question arose.
JBrinkworth, post: 340068, member: 6179 wrote: IN and KY standards refer to RPA, not RPP. I had this in mind when posting my questions above. It seems there may be a semantics issue here. A bit odd considering Gary Kent advises on the ALTA standards…you would think IN and ALTA would be more consistent with one another.
I agree that RPP is a better descriptor of the quantitative elements of a survey and RPA is more representative of a qualitative approach. Both important, nonetheless. Thanks for pointing that out.
Back to the question…How do you ensure that you are meeting the quantitative elements (RPP as you describe) required by the state or ALTA?
You said…
“I thought I had made it clear, I do not adjust my everyday field work. If it falls within my expectation of erros, I accept it for what it is. Honest measurements with error.“
I get this, and from what I’ve read in your posts, you seem to be a prudent and more than competent surveyor. I am not convinced that a savvy attorney and/or competent judge would accept that statement, however.
In my parts, there are guys who slap the “this survey meets the minimum state standards ….of an urban survey .07 +/- 50 ppm…” who have never ran LS and most certainly have never performed an independent survey of higher order.
I am concerned about the surveyor, not so prudent. That’s why the question arose.
I’ll say this… I use LS. I keep up with about a dozen other licensed surveyors in town. None of them use least squares, all of them do ALTA surveys, most of them don’t adjust their control. These folks range from 10 years to 40 years of professional experience.
You are spot on.
Same around here. Most people just aren’t using it. I get the sense this is true across the country.
Should the standards be revised to be more accessible to the majority of the profession?
What good is a standard if nobody adheres to it?I am by no means an expert on LS. But, I use it, and it has made me a better surveyor.
What good is is a standard if no one follows it and there is no resulting harm? I have seen more actual harm caused from adherence to Alta standards, due to the drastic increase of cost to the project, than if ALTA simply did not exist.
The fact of the matter is that there is no objective way to test that you have achieved the ALTA standard. Different LSA programs have different approaches on how those RPP values are computed.
I don’t understand how a drastic increase of cost can be attributed to meeting ALTA standards. I was specifically referring to complying with RPP. Meeting +/-0.07+50ppm is not that difficult, really.
Assuming that your systematic errors have been accounted for, how much extra time does it take to make redundant ties or turn a couple sets? Running the adjustment isn’t that time consuming either.
A drastic increase of cost? If a client orders an ALTA, they are assuming those standards have been met. The steps needed to meet those standards should be built into the bid.
So true. A product that meets a minimum standard is more expensive to produce than one that does not.
Bow Tie Surveyor, post: 343455, member: 6939 wrote: The fact of the matter is that there is no objective way to test that you have achieved the ALTA standard. Different LSA programs have different approaches on how those RPP values are computed.
Well, using an LSA program to estimate relative positional uncertainty IS an objective method in that anyone will get the same result from the same data using the same program.
It’s true that different programs use different approaches to modeling uncertainty, but that doesn’t mean that any are personalistic rather than objective.
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