Last seen: May 28, 2026 2:28 pm
Once the horizontal datum is stated then the ellipsoid is given by definition, regardless of whether the coordinates are expressed as State Plane, UTM...
Kevin, I can appreciate the struggle you're having trying to ensure the integrity of your PLSS DB. Below are some suggestions for your consideration:...
You can find the definitions of the order and classes of control in:Federal Geodetic Control Subcommittee -- Standards and Specifications for Geodetic...
John, I assume you mean NAD 83 to NAD 27 was about 100' in your area - which is correct. NAD to NAD 27 in the Pittsburg region is more like 3-10 ft.
Great comments, especially from Mark, Mike, Norman and MightyMoe. I had the honor of being part of the NGS NADCON evaluation and implementation effor...
ChainingWhile I know that quite a number of surveyors performed the right procedures I know that in the two companies I worked for before I moved to N...
ChainingWell that didn't line up the way I had hoped it would.
ChainingIt can a chore to get 1:10,000 chaining. Assuming you have a 100ft chain that had been calibrated recently against a CBL, which I suspect mos...
Very good Shawn. Also note that all of these other services, with the exception of the Canadian PPP, will be using only those CORS that are part of t...
NGS Data BaseI don't mean to be rude, but anyone who thinks the NGS database is nothing more than an autonomous computer sitting on a desk somewhere a...
There is an on-going effort by the American Association for Geodetic Surveying (AAGS) to create some form of a training program in collaboration with ...
This issue was raised by a number of us at NGS some time back - no go. NGS does not have the resources to construct and maintain such a program. Wit...
Dane, I think you would be safe to use the tidal datum to NAVD 88 offsets for station 9414290 to apply to HT0728. Just to be safe, send your request ...
I am deeply saddened to hear this. I've know Alan for about 20 years. He was very active with FIG and I worked with him on several groups with Commi...
Heights Stamped on USC&GS BMsUSC&GS discontinued stamping the heights on bench marks in the mid-1930s. Differences with respect to the 1912 d...
I had to think about this one. I get 9, MD/DE, MD/DE/PA, NJ/NY/PA, VA/NC, LA/AR/TX, AZ/CO/NV/UT, CO/NE/WY, CO/NE/KS and CA/OR/NV
ok- go ahead and proveThe vertical datum in 1923 was referenced as the 4th General Adjustment of 1912. It was replaced by the Sea Level Datum of 1929...
You can find info on the Fort Worth and other CBLs on the NGS web site -- CBLS
It was very common practice for USC&GS/NGS to set a "2" station (or 3, 4 or whatever) close to the location of a previously existing station. The...
If your starting with NAD 27 coordinates transforming them to NAD 83 doesn't make them more accurate, it fact probably just the opposite (although onl...