Bearings are grid: grid north=geodetic north at longitude 100degreesW.
I've checked that and for small surveys you really need to change the latitude a bunch before the bearings might start slipping along the given longitude, but it's probably best to include the lat of the origin also.
You'd have to ask our State Board of Registration those questions. Those are the state's Minimum Technical Standards.
Lets say Tropical Storm Irene wipes out all but one monument, and nearly all the evidence of occupation. Apart from the one monument, the property is 2 to 30 feet lower than it used to be and all that's left is sand and rocks. The mobile home that used to be on the site is 2 miles downstream. The most recent survey indicates a basis of bearing of geodetic north. Would it be better to reestablish the other 6 boundary monuments by establishing geodetic north on the ground and setting out the other monuments based on the numbers and bearings on the survey plat, or would it be better to throw up one's hands and say the deed is inadequate because the property cannot be located on the ground?
> Bearings are grid: grid north=geodetic north at longitude 100degreesW.
>
> I've checked that and for small surveys you really need to change the latitude a bunch before the bearings might start slipping along the given longitude, but it's probably best to include the lat of the origin also.
That's an idea....another thought is that you just give the rotation angle to true north at one point (or for the whole project if it's a "small survey"). Nothing wrong with giving a lat. and long. for your project, it only helps define the location on the globe.
That's what I'm talkin bout! (sorta!)
So, I am not totally clear on what you are saying. If you take two points and do an inverse between them in the original control basis, which you said was derived from GPS and converted into NAD27 in the 90's.
Then you go out tomorrow and do an opus session on the points, send it in, convert it to NAD27, NAD83? and then do an inverse and the bearing is the same as it was in the 90's?
I am impressed with that.
Basis of Distances:
All distances shown hereon are based on 2640.00 feet between the Southwest Corner, and West ¼ Corner of said Section 16, as shown on the 18?? GLO Plat.
Loyal
Basis of Distances:
Lol. That's awesome, Loyal.
I's think that whole regulation being quoted from is a basis to RESURVEY from the deed and has little to do with retracing anything. Retracement depends on finding an established boundary from physical evidence on the ground. Resurvey is when you can't find anything to retrace and run out the deed. Boundary retracement is based in the law and resurveying is based upon the math. Surveyors are authorized to retrace only and a resurvey must be authorized by all affected landowners. Most of the land surveying I see being done is unauthorized resurveys.
Or you could go as far as needed in all directions until you found an existing monument, and proportion in the missing ones.
I understand the goal is to use the best available evidence. After a major widespread disturbance of monuments, one monument and a basis of bearing could be the best available evidence.
Dashboard in foreground is attached to a Red Cross emergency response vehicle. I haven't heard of anyone having the specific problem of not being able to find their monuments. There were news reports of former land owners loosing their land because it became public boatable waters.
Your examples, and many others, are the exactly the reasons why the licensed professional's judgment should be relied upon, not some inflexible statute or rule most likely dreamed up by NON-surveyors who think they know what is best for everyone in every possible scenario.
That is why we are supposed to licensed professionals, not technicians merely carrying out the latest whim and fancy of whatever a licensing board hands down from on-high.
I burn in a pair of gnss points and use that for my basis of bearing. State on the plat bearings shown hereon are referenced to grid north " insert zone" like KYSPCS Zone 1602, NAD83 2011. Also state the method of gnss observation, like network RTK and where I received corrections from, such as CORS network.
If I dare to put a coordinate on my POB, I give the vertical datum and geoid model used with an elevation to the nearest foot.
Is that enough information for one to follow?
You know it is. However, we are strictly talking about bearings.... This can be strictly a product of a sun shot. Done correctly, you can do a sunshot, and then, by computing your lat lon of observation, and the central meridian of your grid projection, you can put your project on State Plane Grid North, without GPS.
I have done this many times.
Nate
> I burn in a pair of gnss points and use that for my basis of bearing. State on the plat bearings shown hereon are referenced to grid north " insert zone" like KYSPCS Zone 1602, NAD83 2011. Also state the method of gnss observation, like network RTK and where I received corrections from, such as CORS network.
>
> If I dare to put a coordinate on my POB, I give the vertical datum and geoid model used with an elevation to the nearest foot.
>
> Is that enough information for one to follow?
the answer is this question: 100 years from now will the reader know what monuments were used, and what coordinates, and which epoch was used in those "corrections"?
I think not. Maybe even next month there could be another analysis...
If you were to add the PID, epoch, and record coordinates used on those control points then you have something for the ages.
It is just a copy/paste away from a hell of a lot better.
remember, not that long ago 10' in direction or a couple links in distance was just fine. 🙂
If you were to add the PID, epoch, and record coordinates used on those control points then you have something for the ages.
Maybe: I needed a NAD27 value for a NGS monument, I have data sheets for almost everything in the area but this one monument. Looking on the web site the point no longer lists the NAD27 values in its list of superseded control. :excruciating:
I did a lot of that in the 1980's. Sun shot converted to grid bearings. Then it was NAD 27.
Mighty...
That's odd...
What was the PID?
Loyal
LOYAL
Loyal, I not sure it matters, you may want to check out some of your favorites, looks like they have all lost the NAD27 numbers, this one is QV0432. I was able to find the XY coordinate for it in some other data that I had, I needed it for a very good reason, but can't get it from the new datasheet......
Keep all your old sheets they may come in handy :-@
LOYAL
QV0432 SUPERSEDED SURVEY CONTROL
QV0432
QV0432 NAD 83(1992)- 45 03 52.38542(N) 106 51 37.67746(W) AD( ) 3
QV0432 NAD 83(1986)- 45 03 52.37850(N) 106 51 37.66615(W) AD( ) 3
QV0432 NGVD 29 - 1204.8 (m) 3953. (f) VERT ANG
QV0432
QV0432.Superseded values are not recommended for survey control.
QV0432.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.
QV0432.See file dsdata.txt to determine how the superseded data were derived.