WASHINGTON, March 28 (UPI) -- The agency that manages data from U.S. spy satellites is exploring ways to map the nation's entire electric grid as part of efforts to protect infrastructure.

The National Geospatial-Intelligence Agency wants to create an "electric energy infrastructure dataset," including the geographical locations of all transmission lines, power plants, substations, and generating units, to show the way power flows through the system and where the control points are, the agency said this week in procurement documents.

In a so-called sources sought notice, the NGA asks any companies that could provide such a database how accurate their geo-locational data is, what format they could provide the database in, and how often it would be updated.

The database is being established, the notice says, "in support of the federal level homeland security, homeland defense, and emergency response and recovery missions to protect the nation's infrastructure."

The agency says it needs a license for the database that will enable it to share throughout the U.S. government, including the military; with foreign partners including Canada, Britain and Australia; and "non-federal governmental disaster/emergency response agencies and/or personnel supporting the homeland security mission."