The previous posts concerning routines that isolate instrument error fascinate me. Then someone wanted to know who chased millimeters. The words "good enough" were thrown around.
I have field procedures developed over the years and they're probably not very "by the book". But my field procedures are not performed to test any instruments or eliminate any inherent error. I am 100% concerned about the positions I report on my surveys.
My work consists mainly of utility right-of-way work. This required boundary determination. On a lot of my long-line work the control and topo has already been performed, usually with lidar. While we do work within geodetic control, the R/W documents and monuments I produce are recorded in plane geometrics. Very little, if any, of my work extends past a section boundary. This keeps the longest measurements under 6000 ft.
When I draw up a boundary I report the monuments, either found or set, and delineate the lines between them. That data is my primary concern. If I say it's 2645.37' between monuments, I've measured it. While our original discovery locations of boundary monuments is performed by RTK, we check almost every distance and bearing reported on my plat of survey with an optical instrument. And yes, things need tending.
I know it frustrates the hired help to get back out there and actually measure between monuments, or close a short traverse, with instruments they call "Old School"...(the TS). But it keeps me honest.
I keep our instruments in good condition and calibrated. I'm not necessarily worried about a millimeter here or there. I AM worried about a tribrach that is out of plumb or an instrument that is out of calibration. If you're doing it right, that stuff shows up quick.
I guess what I'm saying is good enough, to me, is about 0.03' in 2640'. That comes out to 1:88K. I want my surveys to reflect that kind of precision. I want the next guy to be able to repeat what I've drawn up and rely upon it.
I find PLENTY of other surveyors pins that don't fit their surveys by a tenth or two. I can't, and don't, do anything about that..except report it accurately on MY survey.
I can appreciate the surveyors that can delve into the precision of their instruments. I just simply trust my instruments are good enough. My field procedures were developed over time to locate, identify and rectify any error and I'm satisfied that very, very little gets plotted on anything we put out. I'm an old and simple surveyor that strives to accurately report what I've found, that's all.
Do I survey to millimeters? No. But I'm damned sure that what I write down and what is really out there is within a few hundredths at most. That to me is good enough for the work we do. B-)
I once listened to a short speech by a Surveyor who is also holds a math related PHD. in his words, 'good enough is not a number, it's an identity'. That one sentence has impacted my daily practice and the direction of my career in profound ways...
In my mind, as long as you comply with the standards, you never have to utter the words "good enough".
I had an old Master Chief in the Navy that said, "Good Enough Never Is...". I have even seen this phrase on the side of tanker trucks. The moral of this story is, as long as you comply with the established standards for the type of work being performed, you don't have to halfa*$ anything, say good enough to yourself, and loose sleep worrying if your deceit will be uncovered.
My $0.02
Surveying in millimeters is a great way to catch a blunder. Used to be a switch on the Topcon, so you could shoot in feet AND meters. I guess nobody uses a field book anymore.
I run almost all my data through StarNet. My primary purpose for doing so is to trap blunders rather than to refine precision. Once I've weeded out the blunders - and presuming that I'm collecting enough data to trap them - the precision is there.
:good:
Honesty and Professional Surveying
> When I draw up a boundary I report the monuments, either found or set, and delineate the lines between them. That data is my primary concern. If I say it's 2645.37' between monuments, I've measured it.
In my opinion, the problem is slightly different. If a professional surveyor is going to certify that a certain set of boundary markers has some shape and location (within certain tolerances), honesty requires that he or she have a sound basis for that belief that can be trotted out if questions ever arise.
In Oklahoma, where you can measure a tie clear across the state without cutting any brush, you probably can measure an EDM distance between any two points that you set or locate. Elsewhere, vegetation means that can't always be done and the exercise consists of computing inverses between points that are connected, but usually not directly (OK: "direckly") so.
That's certainly the case in Texas and that's why Star*Net is so valuable if you have realistic estimates of the random errors that one has the honest expectation are present in the work.
In 1978 when we surveyed all of Continental Ranch here in Tucson I had the crew shoot both feet and metres, from both directions, and turn the angles in all quadrants, because I had to have an excellent basis for the future work.
I agree that we as surveyors should understand our equipment and the positional tolerances that we are certifying. The major problem that I see is not so much the accuracy of the field data as the flawed logic in interpreting the original intent of the deed. Both the deed staker and the fence staker have caused much harm to our profession. Both of these groups tend to use the magic button approach to fieldwork. The equipment will always give an answer and making multiple observations is "redundant" according to these groups. Although the problem we see in both the resolution of property lines and bad field procedures is sometimes due to the ignorant's of the surveyor, I contend it is more often due to the sub-professional surveyor's desire to do the project with the least amount of effort for the maximum amount of profit.
The posts where they are picking the fly dung out of the pepper are interesting as going into great detail helps us better understand what we are doing. However, different projects have different requirements for accuracy. A shot to the center of a river cannot require the same accuracy as a property corner in a zero lot line development. Frankly many times, I would be happy to see good enough.
"If I say it's 2645.37' between monuments, I've measured it. While our original discovery locations of boundary monuments is performed by RTK, we check almost every distance and bearing reported on my plat of survey with an optical instrument. And yes, things need tending."
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I'm just curious, when you say "I've measured it." do you mean that you actually measure every distance shown on a plat, or are they computed distances?
This reminds me of the first time I set up an instrument, the old K&E paragon transit with a plumb bob. I set it up and then asked the party chief, "Is this close enough?" His response, without even looking up from his calculations was, "What's wrong with right on?"
I got it right away and went on finishing my set up, "right on."
One of the first Party Chiefs
with whom I worked used to say, "Perfect is good enough."
One of the first Party Chiefs
> with whom I worked used to say, "Perfect is good enough."
One of the hardest lessons for me to learn when I was a young Party Chief was when something less than perfect is actually close enough for the current and likely future purposes. I kept wanting Perfect.
B-)
One of the first Party Chiefs
same here Stephen. I figure if I am shooting for flat, and get as close as I possibly can on everything I do, I am doing pretty good.
One of the benefits of being solo, I get to see and do everything to my standards.
