Last seen: May 28, 2026 2:28 pm
As both Cliff and Gavin have pointed out, maintaining a classical network of passive vertical control points (bench marks) is a losing proposition - n...
Don't forget that the change in the vertical will be accompanied by a new horizontal (geometric) datum more closely related to ITRF. On any OPUS repo...
You are correct, it's just a reference. As I mentioned previously it gives the surveyor some pretty good info as to what's going to happen and allows...
The actual definition would depend on the year the height was determined. In general whenever anyone references the "USC&GS" or even the "USGS" d...
GRAV-D is the process by which NGS is collecting the gravity data required for the new geopotential (vertical) datum to replace NAVD 88 which is curre...
Dale Benson retired over a year ago. I don't know if anyone is left there who know how to research these data.
I would highly recommend that you post your question to the National Ocean Service (NOS), Center for Operational Oceanographic Products and Services (...
Mark was a good friend and a great colleague. He will be deeply missed by those who knew him.
MightyMoe could you please post the PID of the station you missed by almost 6 feet, I'd like to take a look at that. Please also include the NAD 83 p...
Read the documentation linked by GeeOddMike. If you're using CORPSCON/NADCON the 2 sigman (95%) confidence for the transformation from NAD 27 to NAD ...
Using the NGS INVERSE program
Sounds like you're probably working on the western side of the state maybe in Addison County - Scale factors greater than 1 will be very common on the...
If someone at NGS told you that NADCON was rubbersheeting they didn't know anything about the program. NAD 27 had significant amounts of regional dis...
NADCON is the official datum transformation tool for the U.S. to go between NAD 27 and NAD 83. It has a standard deviation of 0.15m (.5') in the lowe...
There's no such thing as WGS 84 (2011). I think you mean NAD 83 (2011). The current realization of WGS 84 is WGS 84 (G1674).
This issue has been reported to the NGS CORS and database teams. Hopefully it will be resolved shortly. It is curious how this would happen since th...
Based on an agreement with the Canadian geodetic survey, NGS does not provide access to control in Canada even if it was used in an adjustment. Canad...
That was sad to watch. Phil should know better than that.