The accuracy of GPS is set to improve dramatically as the US Air Force begins launching the IIF generation of GPS satellites this month. The new craft will eventually replace half of the existing constellation, with the biggest locational improvements taking effect in urban centres.
Boeing is building at least 12 Block IIF generation satellites under the contract. According to the manufacturer, the new satellites will deliver double the signal accuracy. They will offer more robust civil signals suitable for commercial aviation, along with a more secure military signal that resists jamming.
They will have a 12-year design life for long term service and the ability to update the software system remotely for ongoing improvements to operations.
The current GPS constellation provides worldwide 24-hour navigation services with three-dimensional location (latitude, longitude and altitude).
However, it is subject to interference by low-level radio waves, and can be blocked by tall buildings and trees.
The first GPS IIF satellite, SV-1, has been delivered to the launch site at the Cape Canaveral Air Force Station in Florida. The launch of this first second generation satellite is scheduled for 21 May.
The most dramatic improvements will be felt in cities, where signals will no longer be blocked, even indoors.
