August 08, 2006
DC GIS Announces 2005 Planimetric Project Is Finished!
In the past year, OCTO GIS staff have worked to update various planimetric map layers to more accurately reflect the District's ground conditions as of 2005.
The District of Columbia requires a comprehensive range of photogrammetric mapping and GIS database updates and development services. Given the number of changes occurring in the District in recent years, the current 1999 planimetric layers available are no longer sufficient for daily spatial analysis and mapping. In the past year OCTO GIS staff, in coordination with EarthData and New Light Technologies, have worked to update various planimetric layers to more accurately reflect the District’s ground conditions as of 2005. As part of the ongoing DC GIS maintenance and Planimetric Update project, OCTO identified several key layers for updating through change detection and new additional layers* important to future DC GIS needs:
- Buildings (BldgPly)
- Bridges and Tunnels (BrgTunPly)
- Geodetic Control (GeodeticControlPt)*
- Hydro Center Lines (HydroCenterLineLn)*
- Metro (MetroEntPt)
- Obscured Areas (ObsAreaPly)
- Railroads (RailRdLn)
- Roads (RoadPly)
- Sidewalks (SidewlkPly)
- Wooded Areas (WoodPly)
These layers are frequently used and incorporated into daily operations. The planimetric project area covers the entire District of Columbia, which is approximately 69 square miles. Aerial photography, taken in April of 2005, was used to update the planimetric data originally produced for the District of Columbia from the 1999 aerial photography. For layers updated through change detection, features were removed if they longer existed in the photography, were added if new, or were modified if the geometry changed (i.e. building additions). All layers carry a date of capture to delineate which features have been updated. For the downtown area, EarthData thoroughly reviewed mapping tiles that covered the downtown core. Outside of downtown, the contractor carefully reviewed photography for changes on all layers surrounding building or road modifications.
For additional information on the Planimetric Update project, please email us.
The map above shows building changes since 1999.