City of Celina GPS survey monuments are documented on individual data sheets including photographs showing their locations. The horizontal datum is North American Datum 1983, State Plane Coordinate System – NAD 83(2011), Texas North Central, Zone 4202. The vertical datum will be North American Vertical Datum of 1988 (NAVD88) with geiod heights determined utilizing GEOID12B. Two (2) reference marks will be provided for each monument. Existing monuments, established in 2018, are monumented with 3.5" bronze disks set in concrete.