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Survey marker, monuments



Accuracy is vitally important.  Discovering and verifying Monuments that are NAD83(2011), intact, accessible, and of appropriate adjusted accuracy is time consuming.  Alpha RTK has traversed its service territory to find and verify the best survey control network stations.  


We have posted the relevant information on this page, along with an interactive map to help you easily navigate to the stations.  The map is publicly accessible in ArcGIS Field Maps.  You may also download the monument locations in NAD83(2011) ESRI SHAPEFILE or ESRI FGDB file format.  Use the ESRI locations along with your observations + the NOAA tools below to calculate your observed deltas.


We periodically visit the monuments to ensure our network is meeting the utmost standard and we post our observations online in a linked Google Sheet.

Helpful Tools:


NOAA INVERSE Computation Tool

(To compute the forward and back azimuths from north and ellipsoidal distance between two points):


NOAA Computation of GEOID12B Geoid Height:

Bridgeton - JU2269

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