Accuracy Statements

[DWoolley]

Drexyl, TTaylor, RAM, Jay Wright and others:

Thank you for driving this conversation in a productive manner. I appreciate it.

Something that sounds simple is a complex issue with nuances.

To make my argument, consider these basic premises:

1. The professional status of land surveyors is being threatened and may result in deregulation due to the occupational/ trade aspects of land surveying being performed by unlicensed folks without data to support they, unlicensed folks, are damaging the public. Arguably, licensure is little more than a barrier to entry.

The land surveying community, viewed as a whole, is not prepared educationally or technically to argue the necessity of licensure. The license serves as a barrier of entry when viewing the lawlessness, lack of technical skills and lack of licensure oversight of multiple technicians. Also, note the number of complaints and the nature of complaints against land surveyors compared to those of engineers, together with the criminal records amongst the land surveyors. There are many examples. One company was fielding 18 two person crews and office support staff under one licensee. There is no way to responsibly supervise, in a professional capacity, a staff of 50 unlicensed folks. The fact this model existed is proof licensure is not really needed, but can be used to hold the public captive. In contrast, during my early employment in a public agency the policy was one licensee for every 4-6 people and an LSIT to be Party Chief/Surveyor III. In my current structure, we have one licensee for every one technician, a 1:1 ratio with six licensees. Most of the technicians have their LSIT and the NSPS CST I, II and III. Those that do not make their LSIT a priority will be terminated. High ratios of licensees to technicians demonstrates licensure is little more than a barrier to entry.

2. The land surveyors are small group of people in California. Approximately, 4,000 licensees of which 1,000 are out of state. The recent test results yielded 29 licensees of which 31% were out of state. These low numbers translate into many challenges. One challenge will be to fill the demand. For example, earlier this year Caltrans fielded 88 field crews. Caltrans requires a license to be a party chief. Ten of the crews were chiefed by “leads” without licenses due to a lack of qualified applicants. If the land surveying community cannot fulfill the position the licensing standard will necessarily go away.

3. Organized labor had land surveyors reclassified as laborers until this week. It took NSPS seven years to reverse this ruling. The California apprenticeship requirements and organized labor do not recognize land surveyors as professionals. This has ramifications. For example, the Longshoreman incurred a $90 million dollar judgement, currently under appeal as their assets are approximately $20 million, in a fight for two electrician jobs in the Portland Port. That particular terminal remains closed after the tenants simply cancelled their lease rather than deal with the Longshoreman sandbagging their facility. “Land surveyors” dispatched from either Local 3 or 12 totals about 1,000 people. Licenses among this group is as a rare as hen’s teeth, LSIT certificates are equally as rare.

Who among us thinks organized labor will readily recognize the land surveyors professional status? Operating Engineers dispatches grade checkers and other folks that routinely perform land surveying work unsupervised by a licensee – as does IBEW for laying out electrical lines. Has anyone seen the new Hilti surveying instrument made to “layout” (survey) in trade terms contractors understand? Who among us has set a slope stake in the last 10 years? There were consecutive months, for consecutive years, in which I did nothing but slope stake.

We cannot turn back the clock.

The purpose of the accuracy statements is to retrain or train those land surveyor that do not understand measurement. As evidenced here, it is foreign to many land surveyors. If we have to place an accuracy statement on all measured work product, we will hone those skills and the knowledge needed to write specifications, follow specifications, supervise work being completed by others. The role of a professional land surveyor will be to function similar to an inspector or resident engineer i.e. compliance and adherence to standards. We simply will not have the numbers to perform the work in the ways we have traditionally performed. The job of a highly trained land surveyor will be supervision and certifications on large projects on a daily basis. I believe boundary and mapping will remain unchanged - except, ideally, lawfully filing maps, understanding property rights by surveying according the rules (no more record boundaries related to field surveys and two monument tangos) and focus on the adherence to the laws rather than dodging it.

A land surveyor will not be performing most of the topography – this work will be completed by others, mostly unlicensed. However, ideally, the work will pass through a land surveyor that sets the project up with procedures and signs off on the quality/accuracy of the data. The same is true for construction staking. There will not be enough work to field regular field only crews. These folks may well be shared between firms or firms that only broker in field work. Again, boundary mapping will largely remain unchanged.

The accuracy statement is a method to retool a land surveyor’s professional skills to make the community relevant in the future. Land surveyors will also have to become more proficient in their ability to communicate to properly supervise multiple different trades.

I welcome any better ideas or facts that show the error in my perspectives.

Lastly, the unlicensed and/or uninclined will necessarily be purged.

DWoolley

[TTaylor]

IMO, any statement of the quality of a survey should either reference a standard that requires a QC/QA plan including ground truthing or clearly state the QC/QA plan used.

It's the evaluation of the resultant data and it's value for its intended use that is a professional service.

[mpallamary]

Out of curiosity, do surveyors change their procedure and methodology when they perform an ALTA survey? If so, how and if not, why?

Be safe all.

[Jim Frame]

Out of curiosity, do surveyors change their procedure and methodology when they perform an ALTA survey? If so, how and if not, why?

For me the only difference between an ALTA and any other boundary survey is what gets put on the map. The control measurement procedures are the same.

[mpallamary]

Thanks!

Anyone else?

[mpallamary]

I think we should look at something more concrete like Land Court Survey procedures. Is anyone else familiar with them?

[bryanmundia]

I think we should look at something more concrete like Land Court Survey procedures. Is anyone else familiar with them?

Do you happen to have a sample of one of these Land Court Survey Maps? I am interested in the overall look of the map once the fieldwork is completed.

[mpallamary]

I am trying to get a current copy. COVID is slowing things down.

[mpallamary]

More food for thought.

[Randy Mayer]

Any survey I provide exceeds the accuracy requirement of a ALTA survey. The positional tolerances of every point is checked on every survey performed. At least the ALTA standards specify what accuracy has to met. The feds and Caltrans provide accuracy standards and methods required for various types of surveys. Are the old accuracy standards of 1:10,000 for city surveys and 1:5,000 for rural surveys still acceptable for boundary?

Maybe minimum standards of accuracy for various types of surveys should be developed. With out standards in place how do we hold anyone's feet to the fire. With standards in place then the statement on any map would be straight forward and would pertain to survey performed.

Right now the way I see it it's up to the individual to deem a boundary survey is accurate enough. Please enlighten me to any related standard(s) if there any.

Real quick, no calculators allowed:
1) What is the accuracy of a point measured at a 1000.00 feet using a 3 second instrument?
2) What is the amount of error of 1 minute at 300 feet?

These were a couple of things my mentor always harped that I should know off the top of my head, there are many more.

One other thing, when was the last time you calibrated your total station? This morning, this week or this month? Have you ever performed a calibration twice in one day?

Thanks for letting me ramble.

[DWoolley]

Are the old accuracy standards of 1:10,000 for city surveys and 1:5,000 for rural surveys still acceptable for boundary?

Real quick, no calculators allowed:
1) What is the accuracy of a point measured at a 1000.00 feet using a 3 second instrument?
2) What is the amount of error of 1 minute at 300 feet?

Randy Mayer:

Excellent material for an example. I suspect we are on the same page.

The "old accuracy standards" referenced aren't actually accuracy standards. They were blunder detectors. I have vivid memories of folks waving around, ever so proudly, their error of closure being 0.02' on, say, a four legged traverse with each leg being 500'. I would hear them repeat their results, for the next several days, to anyone within earshot. In reality, all that 0.02' represented was the fact they did not have a blunder, nothing more. Frankly, the majority of traverse work performed in the old days, even by low skilled folks, was blunder free. I remember many occasions smiling like Cheshire Cat but never having the heart to tell them it did not represent or have the value they placed on it.

"Blasphemy!" some may say. No. A four legged traverse with 500' legs would yield a theoretical uncertainty, using "standard" total station equipment, of 0.17'. This means the traverse closure of 0.02' (1:100,000) is equal to a traverse closure of 0.17' (1:12,000). Think of a pinwheel with equally spaced numbers between 0.00' and 0.17', give her a spin, and any single number in between is as likely to hit as any other number and actually represent equally the same "accuracy". Restated, the error of closure being 0.04 is as likely as 0.12 as 0.08 etc. Replay the same scenario, the same person was unlikely to wave with pride their 1:12,000 survey closure, although they are the same thing. However, if the error of closure was 0.25' on the same traverse there was a problem, likely a blunder - as they exceed the theoretical uncertainty of the equipment. What sort of blunder? Not being set up over a point, instrument or tribrach out of level, etc. Reference: Evidence and Procedures for Boundary Control, Second Edition, see pages 282 through 284. To quote the book, page 284 "It is just as likely for a closure to be zero as for it to be any other number within the expected range." The quote is restated on page 302 under Closures.

As for question one above, there are two answers, you didn't specify if you were turning angles or directions. If directions, how many other points were in the direction set?

As for question two, everyone our age should remember the adage, 0.03' per minute per 100'.

Thank you, Randy Mayer, for the trip down memory lane, good stuff. If anyone still touts their error of closure, be kind and smile. They know not what they do.

DWoolley

[hellsangle]

Dave,

As you pointed out . . . error ellipses on a good survey are about a tenth.

Let's say the surveyor contracts that he/she is to set corner points . . . and we've all been throwing this silly accuracy statement on maps and calculating a least squares adjustment for several survey-iterations . . . then codifying this accuracy statement/calculation . . requires the surveyor to set another point because his/her "numbers" say so! Again, thinking like an engineer, all caught up in numbers..

This proposed legislation would effectively codify the pin cushion effect. Making us look all the more like embicles to the public with as many differing points in the ground as there were surveys.

As we all know survey practice(s) across our STATE differ. What is the local practise?

More laws = less freedoms.

Crazy Phil


.

[mpallamary]

The more one measures, the more differences are observed.

[mpallamary]

More to consider.

[DWoolley]

Phil:

I have said, multiple times, the accuracy statement on boundary maps will not alter the nature of the work product. Others have expressed their understanding in correctly citing the work on ALTA Land Title survey minimum standards i.e. boundary surveys. Again, noting ALTA/NSPS (ACSM before them) decided decades ago the idea of an accuracy statement, as a minimum standard, was intrinsic to the work. This is a national minimum standard. The accuracy statements are prospectively related to the future of construction, underground utility location, topography and other measurement related tasks that are performed by unlicensed folks. They are not going away. In fact, their numbers will continue to increase and the land surveyors would be wise to define their role in the marketplace. Naturally, idealistically, as a bonafide professional supervising and directing the trades.

Brown, Robillard and Wilson, Evidence and Procedures for Boundary Location (2nd ed. 1981) p. 234-235

“Principle. A found undisturbed, original monument, ...has no error in position. All restored monuments, established by measurements, have some error in position.

…Irrespective of measurements from distant points, the position is unalterable, fixed, and has no error of location.

…All nonoriginal monuments set by measurements from fixed points have some error in position. Although the error may be insignificant, it may be present, and the primary concern of the surveyor is to find starting points that are free from position errors…”.

Somewhere, earlier in this thread, I said a transit and rag tape may better produce the correct boundary location better than a static GPS unit – the correct application of principles over measurement. In my mind’s eye, I see accuracy statements having the exact opposite effect as you have expressed. The understanding of boundary establishment and measurement should eliminate pincushions. If I stated a dX, dY in an accuracy statement and another surveyor’s measurement accuracies were comparable it would be difficult, possibly negligent, to call the monument out of position for anything less than the ellipse.

The idea of accuracy statements is to increase our community’s level of sophistication and in turn, provide a marketable skillset that positions the professionals to provide expertise in a changing marketplace. A loftier goal is to establish the land surveyors’ professional status before succumbing to being a deregulated trade. Do you have any ideas on how to do that?

Being ‘merica, you are free to ride your ship to the bottom – however, kindly provide an accuracy statement as to depth of that bottom.

DWoolley

[mpallamary]

See page 6 of the attached.

If this is worth pursuing, we need baseline definitions and standards. It would be helpful if CLSA or a chapter published a white paper on "accuracy."

https://stsurvey.com/category-1a-land-title-surveys/

[mpallamary]

Perhaps we can use something from the upcoming 2021 ALTA standards.

[mpallamary]

Why reinvent the wheel? Why not incorporate the 2021 ALTA standards?

2021 ALTA


E. Measurement Standards - The following measurement standards address Relative Positional
Precision for the monuments or witnesses marking the corners of the surveyed property.

i. “Relative Positional Precision” means the length of the semi-major axis, expressed in meters
or feet, of the error ellipse representing the uncertainty in the position of the monument or
witness marking any boundary corner of the surveyed property relative to the position of the
monument or witness marking an immediately adjacent boundary corner of the surveyed
property resulting from random errors in the measurements made in determining those
positions at the 95 percent confidence level. Relative Positional Precision can be estimated
by the results of a correctly weighted least squares adjustment of the survey. Alternatively,
Relative Positional Precision can be estimated by the standard deviation of the distance
between the monument or witness marking any boundary corner of the surveyed property
and the monument or witness marking an immediately adjacent boundary corner of the
surveyed property (called local accuracy) that can be computed using the full covariance
matrix of the coordinate inverse between any given pair of points, understanding that Relative
Positional Precision is based on the 95 percent confidence level, or approximately 2 standard
deviations.

ii. Any boundary lines and corners established or retraced may have uncertainties in location
resulting from (1) the availability, condition, history and integrity of reference or controlling
monuments, (2) ambiguities in the record descriptions or plats of the surveyed property or its
adjoiners, (3) occupation or possession lines as they may differ from the written title lines, or
(4) Relative Positional Precision. Of these four sources of uncertainty, only Relative Positional
Precision is controllable, although, due to the inherent errors in any measurement, it cannot
be eliminated. The magnitude of the first three uncertainties can be projected based on
evidence; Relative Positional Precision is estimated using statistical means (see Section
3.E.i. above and Section 3.E.v. below).

iii. The first three of these sources of uncertainty must be weighed as part of the evidence in the
determination of where, in the surveyor’s opinion, the boundary lines and corners of the
surveyed property should be located (see Section 3.D. above). Relative Positional Precision
is a measure of how precisely the surveyor is able to monument and report those positions; it
is not a substitute for the application of proper boundary law principles. A boundary corner or
line may have a small Relative Positional Precision because the survey measurements were
precise, yet still be in the wrong position (i.e., inaccurate) if it was established or retraced
using faulty or improper application of boundary law principles.

iv. For any measurement technology or procedure used on an ALTA/NSPS Land Title Survey,
the surveyor must (1) use appropriately trained personnel, (2) compensate for systematic
errors, including those associated with instrument calibration, and (3) use appropriate error
propagation and measurement design theory (selecting the proper instruments, geometric
layouts, and field and computational procedures) to control random errors such that the
maximum allowable Relative Positional Precision outlined in Section 3.E.v. below is not
exceeded.

v. The maximum allowable Relative Positional Precision for an ALTA/NSPS Land Title Survey is
2 cm (0.07 feet) plus 50 parts per million (based on the direct distance between the two
corners being tested). It is recognized that in certain circumstances, the size or configuration
of the surveyed property, or the relief, vegetation, or improvements on the surveyed property,
will result in survey measurements for which the maximum allowable Relative Positional
Precision may be exceeded in which case the reason shall be noted pursuant to Section
6.B.x. below.

[mpallamary]

https://archive.amerisurv.com/PDF/TheAm ... er2007.pdf

[mpallamary]

https://geospatial.trimble.com/blog/mee ... -standards

[mpallamary]

https://cdn.ymaws.com/www.acrel.org/res ... 000039.pdf

[David Kendall]

ACCURACY STATEMENT EXAMPLE.jpg

The attached example is an excerpt from a draft record of survey which originated in Southern California

I have said, multiple times, the accuracy statement on boundary maps will not alter the nature of the work product.

Measurement accuracy standards have little to nothing to do with boundary establishment. Outside of measurement they are practically unrelated. Folks understand the correct boundary could be better established with a rag tape and transit than static GPS.

Mr Woolley-

You have said this several times on this thread. My ears perked up the first time I saw it because I have been scratching my head for months about how this proposal was going to affect my Record of Survey. Turns out it doesn't?

Are you saying that the accuracy statement only applies to topographic surveys and utility locations? I find this confusing as the placement in the LS act implies to me that it will directly affect our Record of Survey procedures.

How will the LS act affect notes or statements on topographic maps and utility locations which are largely unregulated?

I do not find the excerpt above meaningful

This one includes make and model of total station and GPS receiver and software brand. A previous poster in this thread specifies error ellipses down to .016' at 1sigma.... Nonsense!

Can you explain the value of this?

Please present some concrete examples of how this will be applied. I have asked four or five times for this information in different venues - board meeting, webinar, email, etc. My patience is waning.

I'm afraid that even though the idea may have merit, it is dead in the water as it may be too esoteric for the LS community to accept.

At this point someone, who I believe was a supporter, moved to table the item for a later date and the motion to table passed.

I was the person who tabled the original motion. I do not know at this point if I am a supporter or not. I have been gnawing on this for months now. I find the discussion intriguing and I would like to see it continue so that we can flesh it out.

[mpallamary]

The traditional way to advance a new concept or, to promote new methodology is to support it with a technical dissertation such as a white paper. The paper could be disseminated and subjected to peer review and then, if it is sound, adopted and promoted. It assures cohesion and standardization of the topic at hand. It should read like an executive summary.

What is the problem?

What is the solution?

What are the benefits?

How is it implemented?

[mpallamary]

A model perhaps.

https://giecdn.blob.core.windows.net/fi ... pdated.pdf

[mpallamary]

https://assets.tequipment.net/assets/1/ ... epaper.pdf