Listen up clover breath.. err Your Holiness,
Because I am in Monaco at the Fairmont Monte Carlo with Padens Nun. (Don't tell him)
Have a great FRIDAY! B-)
I know it sounds funny
I know it sounds funny, but in many areas of the country, surveyors fudge their measured data to agree with record. Personally I think the idea is as crazy as setting monuments in the middle of the road!
> I don't understand the resistance to simply reporting on your survey what you measured. I just have a layer for record boundary and a layer for field boundary, different label styles for each and label both boundaries on my maps. Why not ?
I have no problem with your approach, but to answer the "Why not?". Showing record and measured for a few seconds or few hundredths is what adds to the statement I hear from the general public so often that, "Two surveyor's never agree" which then makes those same people question our profession.
Just a thought.
Scott
I agree completely, what's wrong with showing record and measured? Even if its a few hundredths and a few seconds?
It tells me that they actually surveyed it.
The argument that the public does t think surveyors agree is hogwash. If you can't explain that to your client, there is something wrong.
I do not buy that 30+ monuments are within positional tolerance no matter how good you are at setting monuments. Especially after five years. Things WILL move on there own with freeze/thaw or saturation and drying.
I call bull s h i t
> Me too. Today’s Florida Board of Land Surveyors should absolutely reconsider this rule. I ignore it for the most part. It serves no purpose other than to confuse the people who use the survey.
>
> Have a great weekend! B-)
There are a few things I'd like to rewrite in MTS. While we're on the topic of this current thread, I think the requirement of redundant ties to monuments is outdated as well. I do think it's good practice, but not sure it's necessary to protect the public. Think about it, if you are using a one second gun (like we use) and then use the method of calling one tenth "close enough" to not show a difference between record and measured, isn't it just a waste of time? I could argue the monuments are just nothing more than symbols shown on the drawing, as they really aren't really tied down to anything.
A few years ago I staked a property line at my parents' house. I ran the traverse twice, once with redundant measurements and again just with single ties to the points. In the end, both traverses closed under one hundredth. Granted, it was not a very long nor complicated traverse, but I think it should be left up to me to decide what is sufficient to get the job done. If your crew can't generate a closure of 1 in 10,000 feet (highest closure requirements in code here in Florida) with the equipment available today, there is an issue.
Andy
> I don't understand the resistance to simply reporting on your survey what you measured. I just have a layer for record boundary and a layer for field boundary, different label styles for each and label both boundaries on my maps. Why not ?
It's not a resistance on my part. It only happens when literally, the values of the subdivision plat fall on the rod. I'm not going to show a few seconds different or a few hundredths. The very second that my values don't fall on the rod, calls vs. founds are shown.
FWIW, I do maybe three surveys all year where I just show the record because it's so close to what is on the ground.
given the conditions of the typical bovine this time of year, I'd bet he probably smells like clover on both ends....;-)
Andy
Yes, That sounds about how I do it too.
It's about the monuments.
Over the last couple of years I have gotten more comfortable with the half foot of "slop" as a standard.
Boss #1 taught me that in the transit/chain days that every setup added about a tenth of error. So you go around a block, then set a work point in the backyard, you are at half a foot. You hope. This is where the "good practice" of coming from the nearest monuments comes from. If you had to bring it in across town in the old days it got pretty loose (unless you had some repeatable bearing basis or geodetic control to check in to)
I just loathe it when I see a survey where someone claims to have done some fieldwork and then doesn't tell you what they found, because it was close enough to the record that they don't want to "break the record". This does not help the surveyors who follow to know if the monuments were disturbed or placed in agreement with the original plat or subdivision to begin with. Sometimes the best clue they give is that everything is per plat, but all the mons are labeled "found 0.35'N and 0.23' E of calc".
We can measure it better now but that doesn't make the people we follow wrong.
Thank you all very much for your comments.
I can understand labeling measured and record, on occasion I do it too, SO LONG AS IT'S OBVIOUS WHICH ONE YOU ARE STANDING BY.
When yoiu just change text style it's not clear as to what you are, as a professional, defininf as a boundary.
When I do it, it's the bearing and sitance tha i have measured and am holding, and then in parenthisis I will put (Deed = xxx) just to show that I am aware there is a differenceand have noted it.
If I am working in a well monumented subdivision then I will show record if it hits the monuments, and falls within an acceptable level of tolerance.
You have to consider that if you ALWAYS hold measured over record you can be creating non-conforming lots, by shorting frontge or area. You're not anyone a favor if you show 99.98' of frontage between existing bounds and 100.00' is required.
You better be damn sure of your work if you start doing that! And remember the original intent is to create conforming lots!
AMEN!
:good:
:good:
fudging
> You're not anyone a favor if you show 99.98' of frontage between existing bounds and 100.00' is required.
>
!
Precisely the reason why the original surveyor should have made the lot 101.0' to avoid the problem.
I guess the real question is: how much does the measured value have to differ from record before you stop fudging? 0.02' , 0.2' or a foot?
fudging
Giving an original lot some margin above the required minimum definitely sounds like a good idea.
But this topic has come up before and some people say that if the lot was created, platted, and approved by the powers with the original surveyor's measurement of 100.0 then subsequent measurements a little smaller do not invalidate that approval.
Is this not true in your jurisdiction?
fudging
I haven't pushed the issue, and it's not likely that I would, unless the error/blunder was large enough to have siginifcant impact. And there isn't any magic number to pull anduse, it's a case by case "Art of Surveying" decision.
Andy
If that's about what you do, then you should be able to at least entertain the possibility that the 2nd surveyor in Jim's opening post found that to be the case.
Granted, finding a whole block in which every monument, relative to every other in the block is only +/- 0.05' from the record position is not very likely. But it is possible.
Whether or not it actually is can't even begin to be assessed until some field measurements and site investigation are made. thus, it's best to reserve judgment until sufficient facts have been collected.
Define "fudging"
Sorry Perry, but your assertion that the original surveyor should have intentionally placed an extra tenth or even an extra foot in each lot doesn't make sense.
Do you believe your measurements to be exact? Are your's close enough to exact that yours should be considered the defining "true" value of any distance or bearing once you've reported it so that any subsequent surveyors are required to calibrate their equipment to match your "true" values?
Consider these points:
- What is the least count on your measuring devices? Is your equipment capable of making repeated measurements (on subsequent trips) to the nearest second of arc and 0.01', and do so consistently on several subsequent visits to and measurments of the same set of lines and points?
- What is the cetering error of your tribrachs? What is the bubble sensitivity on them and on your prism pole or GPS receiver?
- What is th epublished per measurement standard errors of your measuring equipment?
- Are you able to report your actual unadjusted measurements and produce a perfect closure using them, or do you adjust your control and other observations and then report those adjusted values as "measured" on your maps?
- Can you assure others that your positional uncertainties in your surveys of any given point will result in less than 0.01' in any reported distance and less than 01" along any reported direction of your survey?
If you can't meet those standards every time you perform a survey, then you cannot say with absolute truth that you measured 99.99'. The limitations of your equipment, the reasonable methods of measurement, the condition of being human and operating imperfect equipment dictates that there is always some level of uncertainty in your reported distances. In reality, your measured distance would be more like 99.99' +/- 0.03' if you were reasonably careful in making your measurements throughout your survey of an entire block.
In fact, if you check an inverse between two found monuments based on raw, unadjusted measurements and find the inverse to yield 100.01', but you then adjusted your control prior to making your final boundary location determinations, as is generally accepted good practice, then by your standard that one must report their measured distances on their maps, wouldn't you be falsifying the data to report the adjusted value of 99.99'? If your raw inverse was 100.00', wouldn't you be falsely reporting that the record was incorrect?
Now, to be clear, I don't think that there is necessarily anything wrong with reporting such minor discrepancies between record and your "measured" (actually, adjusted) values from your survey. I do think that in some cases, it can lead to undue consternation by landowners who do not have a clear spatial concept of the insignificance of such minor discrepancies. The surveyor who reports them must be prepared to exercise a great deal of patience with such people, realizing ahead of time that the same misunderstanding that led to their concerns will also impede a quick understanding of any explanations offered, and that simply blowing off their concerns is not a professionally acceptable option.
The surveyor that takes the inherent uncertainties of one's own measurements into account and understands that if the record value is within the 95% confidence error ellipse of his own calculated values, that his own values are, by definition no better a representation of the "true" value than is record, has a better understanding of what he has measured and can therefore make better decisions about what values to report and how to report them.
If you consider your map to be only for the use of other surveyors and of no use to any landowner, then you should always report your "measured" (adjusted) values no matter how insignificant the differences from record. Other surveyors, presumably with a competent understanding of errors in measurement, can use the magnitude of those differences to help assess the relative quality of the measurements of the two surveys.
If you consider that your maps will be used and referred to by other surveyors, landowners, and other non-surveyors alike, then you should be cognizant of how your data may be perceived. A reasonable, competent surveyor may, in exercising good judgment, decide that discrepancies that are less than the probable errors within his own survey are not worth showing because of the misunderstandings of non-surveyors who might reasonably have use of the map.
The idea that the original surveyor should have deliberately oversized the maps is ridiculous because it presupposes that he would have had no cofidence that his own measurements would meet the standard of care of other surveyors of that time, working under similar conditions. It also presupposes that the law demands dimensional perfection which would not be possible until Mr. Williams comes along in 2013, being the first surveyor with the ability to provide it. Or more accurately, with the self-perception of being able to provide it.
If the surveyor was going to oversize the lots, should he have then reported the dimension he actually measured (e.g. 101.00'), or should he have just considered it a "safety factor" against the uncertainty of his poor measurements and still reported 100.00'? Was he supposed to have precognition of future changes in zoning laws or how local planning officials would interpret them?
Realize that if the surveyor was going to deliberately oversize all lots, then he is taking up land into each lot that could have been used to form additional lots. Should the landowner/developer be required to forfeit the value of one or two lots in a subdivision in order to cover the surveyor's inability to measure to reasonable standards?
Or is it more reasonable that future surveyors, planners, and building officials take the reasonable measurement errors of past and present measurements into account and recognize that a reasonable effort was made to meet the zoning standards at the time the lots were created?
Not trying to pick a fight. Just giving you some things to consider that you have apparently overlooked.
Andy
Um, this is an internet message board. I'm not involved in this project and someone asked for our "opinions". If I was 'reserving judgement' I wouldn't be here.
Well in that case...
Let's not consider anything beyond our first impressions and just shoot from the hip with reckless abandon!
Just poking a little fun Andy. I understand. I tend to put too much time and thought into some of these online discussions.
