Job Location: Fairfax, Virginia, United States (Onsite/Remote) • Performs development, maintenance, and refinements of ground GPS based structured geodetic control network, spatial grid reference system, and airborne GPS system for aerial photogrammetric data processing and adjustments. • Determine the underlying geodetic vertical and horizontal control geospatial datum accuracy, and reliability; and develop specifications and procedures to accomplish required data standards. • Perform sophisticated data processing and transformations and statistical analysis of ground and airborne GPS data using complex spatial data modeling including on-the-fly solution techniques. • Based on the work required, the consultant may need knowledge and experience with the following: geodetic horizontal and vertical reference datum; national, state, and global spatial coordinate systems; national spatial reference systems (NSRS) data standards; Ground GPS and Airborne GPS data acquisition and processing; geoid modeling and datum transformations; complex network modeling and adjustments; geodetic project planning, designing, and implementation and the application of GPS derived orthometric modeling and adjustment