In 2011, the City of Falls Church Department of Public Works contracted with a surveying firm to establish 30 new survey control monuments in accordance with Blue Book procedures by National Geodetic Surveys (NGS). The monuments were accepted into the NGS database in January of 2012.
The new monumentation attained Future Generation Computer Systems (FGCS) Class C.
First order global positioning system (GPS) positional tolerances and RT-1 classification
For vertical control, the monumentation reached FGCS
Third order specifications level with a Leica digital level following NGS guidelines
The method used was a modified
approach that integrated the NGS Guidelines for Real Time v2.0.04
specifications and conventional GPS specifications published by NGS.