Analyzing older deeds – closure, Autodesk Land Desktop 3
Older deeds, for example, those based on surveys which report bearings to the nearest five minutes and distances to the nearest 3 inches, almost always have an error of closure associated with them, typically less than a foot. I understand that better evidence will almost always govern over bearings and distances, but nonetheless as a preliminary tool, or in cases where no better evidence can be found, it seems reasonable to adjust the bearings and/or distances in order to “close the deed”. In some cases, it makes sense to hold one distance or one bearing as superior, and in other cases, to distribute using some uniform distibution process, i.e. compass rule. In other cases, it might be appropriate to hold bearings and adjust distances, i.e. Crandall. I understand that judgement is required and that mathemagics has its limitations.
My question has to do with how to do this stuff in Autodesk Land Desktop 3. I know this is older software, but would appreciate any help or suggestions that might be offered.
If I use “Lines/Curves > By Direction” and start at the Point of Beginning of the deed, I can draw each of the lines of the lot, and the “error of closure” can be seen graphically. If I subsequently use “Points > Create Points > Manual” I can create a point at the beginning and end of each line drawn.
Now, it seems that “Analysis/Figures > Traverse Loops” is the area in the software where I might be able to adjust these deed figures, with many different options (horizontal adjustment can be None, Compass, Transit, Crandall, or Least Squares). But, it seems no matter what I do, I get an error message after defining the loop, when I attempt to “Adjust Loop”.
The message reads: “Error: First Occupied Point does not have known coords.”. If I list the points, they’re all in the point database. I have searched online and it seems that this might have something to do with the raw data file, which I do not import into Land Desktop (rather, I typically just import an ASCII text file containing the points PNEZD).
Any ideas how I can get this to work? Or, should I buy Carlson now?
- 16 Replies
You Leave The Deed Plot Open
Unless you find a prior deed with a better description it is what it is.
You put on your meausrer hat and then go out and find the evidence in the ground and/or in the form of adjacent deeds that close better and are supported by monumenrs remote to your parcel.
Then you put on your surveyor hat and “do the least violence to the record” following the rules of evidence.
Paul in PA
You Leave The Deed Plot Open
No adjustment needed…..what do you think we did before the advent of CAD. I have threatened to turn off the CAD for my employees who are constantly plotting deeds and trying to orient them in a big jigsaw puzzle. Take the deed information and analyze the evidence.
I dumped LDD when it was known as DCA (for the programer David Allen).
Carlson is more surveor friendly and intuitive; no I’m not a salesman.
So, I would imagine LDD can “adjust” your polygon, but BEWARE the temptation to adjust a deed description simply to satisfy your mathematical desires.
You Leave The Deed Plot Open
I assume you’re talking about a case like I have described where the closure is acceptable for the time in which the survey was done. In this case, having a closure of less than a foot most likely represents the error associated with the transits and distance measuring tools of the day, a transit which could read angles to 5 minutes, and distances read or rounded to the nearest 3 inches. I agree the closure is meaningless, and point well taken.
I’m dealing with a particular situation in which bearings on one side of the line are cited 10 minutes different than the bearing on the other side of the line, and I’m thinking that analyzing the closure might help to discern which was the “correct” bearing on the original plan which was cited by all the deeds, but which plan is not on file at the Registry. Thinking that the “incorrect” bearing is the result of a scrivener’s error. Scant evidence in the field. One original physical monument cited in the deeds at the northwest corner of the subdivision at the intersection of the sideline of two streets. I’ve got both a stone bound and an iron pipe there, right next to each other. The deeds cite bearings and distances, with reference to subdivision map which can’t be found. Lots of fences. Old fences. Distances are close but don’t match up too well. Subdivision was done in 1896. Everyone who might know anything is dead.
That was helpful for me to imagine life before CAD.
If you have no other evidence for a series of courses, and you are trying to close the described courses between the evidence you do have, you should adjust the courses to a level of precision commensurate with the rest of your survey.
If you are working in a jurisdiction where you must file your surveys and there is some level of governmental review (technical correctness, etc.), you may need to provide a closure report, meaning that your boundary must close.
I do as you do to initially place the lines, using “lines by direction”, I then rotate them as necessary to get onto the basis of bearing used in my survey. After that, I’ve come up with a fairly quick adjustment method that is essentially a compass rule, but utilizes drafting methods and a spreadsheet because it’s easier and more reliable than the PITA Auto desk traverse adjustment routines that never seem to work right anyway.
On the spreadsheet, I enter the distances of each course in Column A, produce a running total in Comlumn B, and a ratio of (total at end of course)/(total of all courses).
In the CAD drawing, I draw a line from the end of the last course entered to the fixed point it is supposed to close on (misclosure segment). I then copy that line to the end of each course to be adjusted, and scale the copied misclosure segment by the ratio corresponding to the end of each course from the spreadsheet.
I then use grips to snap the vertices of the courses from one end of the scaled misclosure segment at the vertex to the other end of the scaled misclosure segment. I finish by erasing all of the copied & scaled misclosure segments. Done.
Admittedly, it is a “band aid” work around. If anyone has a better solution (other than different software – employer is married to AutoDesk), I’m all for learning it.
You Leave The Deed Plot Open
I have to agree with NYLS.
Why do you have to have a mathematical closure on the previous deeds? Why not just record the distances and the angles between the bearings and go to the field with that? See what works with what they have left for you. All of us know that back in the old days, they turned the angles, right? The two adjoiners show bearings 10 minutes off, but the the angles match! Wow. Now we have something to work with. This is the typical basis of bearings stuff that Evan talked about below.
Just between you and me, if I have a rebar and an old stone fence, I am on the stone fence. As a surveyor I can tell which one is older and which one more realistically separates the two properties. Research is important, but so is the field work to apply what you have found in the research. Maybe some of us are over thinking it before going to the field. Just think of all the deeds that don’t provide any bearings or distances for our guidance! What are those surveyors going to work with? Oh. I guess we are lucky to have so much information! Let’s not abuse it.
Evan, thanks for your post. Included in Wolf and Ghilani’s text is a simple traverse adjustment program based on the compass rule “Wolfpack”. Input is a text file containing raw distances and bearings. Output is a text file containing adjusted distances and bearings. It’s free software as far as I know. I wonder with some sort of script in AutoCAD if you could essentially automate the process. Another bandaid. From what I understand, Carlson has many of these adjustment functions built in.
Analyzing older deeds – closure: Copan
> … “Wolfpack”. Input is a text file containing raw distances and bearings. Output is a text file containing adjusted distances and bearings. It’s free software …
Another option is our Copan software. It’s totally free and easy to use. We use it a lot for what we call “map traverses” (analyzing and adjusting bearing-distance traverses). It has a lot of other survey tools as well.
> … From what I understand, Carlson has many of these adjustment functions built in.
Yes, Carlson works well. I don’t know about closing a given deed description though. Never had to/wanted to.
Wolf and Ghilani Not For Commercial Use
It is an educational tool and produces results very close to Star-Net.
Plus you do not adjust the work of others without verifying it in the field.
Paul in PA
> Evan, thanks for your post. Included in Wolf and Ghilani’s text is a simple traverse adjustment program based on the compass rule “Wolfpack”. Input is a text file containing raw distances and bearings. Output is a text file containing adjusted distances and bearings. It’s free software as far as I know. I wonder with some sort of script in AutoCAD if you could essentially automate the process. Another bandaid. From what I understand, Carlson has many of these adjustment functions built in.
I believe/if I recall correctly (I could be wrong) that Wolfpack is a Least Squares adjustment.
You might try the “Transform’ program from Primacode (Dennis Drum) This uses scaling to adjust to fit..
You Leave The Deed Plot Open
I respect that you question isn’t totally bein addressed by NYLS, and Luke, but I think their caution is quite valuable. There is more to it than ‘appreciating’ what some went through before CAD. You might also remember that the logic process used may well be how some boundaries including yours have already been resolved. I don’t have a problem with looking for the most likey scrivener’s error, finding something that “pops” the closure into place, or even adjusting the math. I am just pointing out that ‘bust’ or no, correct or not, the original document is, in essence, “supreme” and to a certain extent “without error”. Your final conclusion your opinion as an expert, of the interpretation of the deed. It is hard to discount how earlier surveyors may have already solved this particular problem, and where boundary rights may have already ripened based off of earlier surveys and earlier interpretations of that first deed.
Sorry I am not really helping with your original question, it sounds like eap has already addressed. Just some ramblings of my own. (my posts don’t always “close” so to speak) 😉
You Leave The Deed Plot Open
Adam
The caution that you and Luke and NYLS suggest is well taken. I’m not trying to say that any sort of mathematical adjustments are going to take precedence over better evidence in the field. So I agree with the caution and thank you all for the good advice.
Analysis of the closure of a deed still seems like it might have some possible merit, for example to ascertain the scriveners error, or for other reasons. And, my post was mostly a “how to” question about the tools one might use to distribute the error of closure. Having the tool is one thing. What we choose to do with it is another.
You Leave The Deed Plot Open
Whatever you do to one deed description it means nothing unless the adjoiners deed descriptions are included in the collection of and evaluation of information. You can’t do that without all of the data. May be some Junior-Senior Rights in play, the parent tract was not properly described or there are overlaps or gaps in the descriptions.
jud
Wolf and Ghilani Not For Commercial Use
I haven’t used WolfPack, but their equations in the book treat the a posteriori statistics differently than Star*Net when you pass the Chi-squared test or fail it on the low side. The issue is whether or not to multiply by sigma-zero.
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