The National Oceanic and Atmospheric Administration's National Geodetic Survey -- the official U.S. government source for determining precise latitude, longitude and elevation -- is undergoing a modernization effort that takes into account advances in GPS and other technologies. The effort is important to all activities requiring accurate positioning information including levee construction projects, the design of evacuation routes in hurricane-prone areas and the forecast of sea-level rise in coastal communities. The modernized National Spatial Reference System will take even greater advantage of newer technologies and better track changes in position and elevation over time to improve and update digital maps.
The proposed changes will affect civilian-federal mapping authorities, as well as state and municipal governments that have adopted the National Spatial Reference System.
"The reference frame in the past was hampered by being held static in time on an Earth that is constantly changing," says Juliana Blackwell, director of NOAA's National Geodetic Survey. "The new methodologies better capture changes, such as subsidence or sea level rise, and the improved points of reference benefit everyone using positioning data for the foundation of their work."
A modernized reference system will allow users to easily calculate accurate positions using a survey-grade GPS receiver in conjunction with a scientific model of Earth's gravity field. In 2009, a NOAA commissioned, independent socio-economic study estimated the value of these modernization efforts to be $4.8 billion over the next 15 years, including $2.2 billion in avoidance costs from improved floodplain management.
"An improved vertical datum means elevation measurements will become more accurate and less expensive, helping the National Flood Insurance Program to reduce the impacts and losses caused by flooding," said Paul Rooney, a Mapping Technology Specialist at the Federal Emergency Management Agency (FEMA).
Photo: Geospatial Corp.