[UPDATE (April 5, 2011): It turns out some of the descriptions I used below to describe a geoid were not accurate. I refer you to this page at the University of Oklahoma for a good description. I’ve ...

My April column addressed the vertical movement at the NOAA CORS Network (NCN). The values at the sites indicate the potential movement of marks in the area of the ...

These columns have focused on procedures and routines for establishing GNSS-derived orthometric heights. There are many ways to analyze and investigate GNSS data and adjustment results. I have ...

The establishment of a seamless chart datum and a transformation model with other vertical datums are the key to unifying sea–land measurement achievements. Since construction of the Chinese Antarctic ...

PARIS. Academy of Sciences, September 6.—M. Bouchard in the chair.—The theoretical tides of the geoid, on the hypothesis of an absolute rigidity of the earth: Ch. Lallomand. Defining the geoid as the ...