Interpret This Bearing of Basis Statement

I suppose the surveyor or CAD jockey doesn't know how to correlate his information to a known line. One could extrapolate within reason that the date of survey would be a decent starting point to begin exploring which horizontal datum was used... you know... if you hehe 😀 really wanted to try and read minds!

Simple. The fence runs due east.

My first guess would be geodetic north. Based only on the presumption that by "GPS Coordinates" he means lat/long. At least he didn't say "Based on TomTom coordinates".

James

"THE INDIVIDUAL WHO PRODUCED THIS DOCUMENT IS LAZY, IGNORANT, OR BOTH"

Maybe the north is based on a single hand-held GPS unit.

Is the stated north within the normal error a hand-gps would result in?

That sounds like an engineer out of Henderson County, Texas.

This one is on a plat I am looking at right now:

1. Basis of Bearings for this survey are based Magnetic North, as observed August 8, 2006.

I call it answering the question, without anything!

(And, there is a curent BLM dependant resurvey of this Section!)

🙂

Nate

I wouldn't have a problem referencing coordinates for the basis of bearings.

What I do have a problem with is not stating where someone can find those coordinates, explicitly enough to know exactly which recorded document is the correct one and if that documents has coordinates to monuments actually out in the field (and identifiable). Also, enough information so that you can relate those cooridnates and monuments to your plat.

As Dave Doyle might say......."Metadata....data about data".

Got to agree with Rankin.......no excuse for something this obtuse.

can't tell. assume nothing.

fwiw - i don't care what bearing basis is used. find 3 pins, rotate and get to retracing.

I'm with snoop...B.O.B. is not worh a whole lot..ususally.

"assume nothing"

you're assuming there ARE pins.....;-)

It depends on what kind of work you're doing, but for most of what I do, if somebody calls a line between two points a certain bearing, I don't really care how it was derived. I'm glad snoop & Joe said it first.

Nate

>
> 1. Basis of Bearings for this survey are based Magnetic North, as observed August 8, 2006.

I bet I've drafted 100 plats with a similar statement. Never understood the hubbub about basis of bearing anyway. Virtually every deed around here is in magnetic.

I'm with Snoop. Find three pins and rotate.

>
> fwiw - i don't care what bearing basis is used. find 3 pins, rotate and get to retracing.

Well normally this would be the case, however the was a substandard survey in that he calls for one point in a fence corner (which has since been removed) and he set the other 4 corners and gave no ties, etc. to how they were established. Best I can tell is that he set 4 rods next to fence corner posts as the existing posts check close. I'm just trying to re-establish his line as I believe it to be in conflict with the line I'm surveying (of which mine is the senior line).

So yes bearing of basis does matter.

I agree.

Our current standards are that we define a line between two identifiable monuments as our basis of bearing and show that on our drawings and refer to it in our descriptions.

It can be said that we could put down anything and just say that East is the bearing/azimuth "because I say so" with no real time spent trying to nail it down to a real world direction.

It is not the most desirable way to do things because many times I have only found one of any of the many monuments mentioned in certain descriptions and had to reference a second point from a best guess and hope to recover something.

Nate

Same here, Perry.

Magnetic North XXXX or Grid North.

Rick

> Our current standards are that we define a line between two identifiable monuments as our basis of bearing and show that on our drawings and refer to it in our descriptions.

Actually, that isn't true in Texas. What the Minimum Technical Standards provide is as follows:

(4) Courses shall be referenced to an existing physically monumented line for directional control or oriented to a valid published reference datum and shall be clearly noted upon any report, survey plat or other written instrument.

Now, I'll grant you that describing the Texas Coordinate System of 1983 as a "reference datum" is on the Jed Clampett side of surveying practice, but there isn't any doubt but that the Texas Coordinate System of 1983 has been "published". It has been enacted into law, after all.

There isn't much doubt but that the TBPLS needs someone to rewrite many of the rules so that they are in Standard English. The rule I've quoted is clearly one of them if some surveyors are understanding it to mean that "Bearings refer to Grid North of the Texas Coordinate System of 1983 (Central Zone)" is somehow inadequate or ambiguous.

Jed Clampett

Jed Clampett had GPS?