You may notice that you can't delete AC folder, but that's alright. 5- Restart your computer. 6- Now, were going to re-register Microsoft Edge in your account. Open the Start menu, search for Windows PowerShell, right-click it from the result, and select Run as administrator. 7- Type the following command and hit Enter : cd C:\Users\UseYourUsername.
A geodetic datum is an abstract coordinate system with a reference surface (such as sea level) that serves to provide known locations to begin surveys and create maps. In this way, datums act similar to starting points when you give someone directions.
Since the Sea Level Datum of 1929 was a hybrid model, it was not a pure model of mean sea level, the geoid, or any other equipotential surface. Therefore, it was renamed the National Geodetic Vertical Datum of 1929 (NGVD 29) in 1973.ean sea level was measured at 26 tide gauges: 21 in the United States and 5 in Canada. The datum was defined by the observed heights of mean sea level at the 26 tide gauges and by the set of elevations of all bench marks resulting from the adjustment.