US: GPS IIF continues the modernisation efforts to provide new space-based capabilities to ensure GPS remains the gold standard for positioning, navigation and timing.
Some of the key capabilities that the new GPS IIF satellites will provide include:
1) Greater accuracy through advanced atomic clock technology –
The GPS IIF series leverages advanced atomic clock technology to greatly improve precision timing, which is the heart of GPS services. These clocks have frequency standards composed of cesium and rubidium technologies that can keep time within 8 nanoseconds (8 billionths of a second) a day.
2) Military signals more resistant to attempted jamming –
Military equipment extensively uses GPS precision timing and navigation capabilities to perform missions safely and more effectively. Naturally, that makes them the targets of jamming attempts.
The military signal on the GPS IIF satellites is specially formatted to counter jammers better than current GPS satellites. GPS IIF also has a variable power capability that allows operators to increase signal power to break through jamming attempts.
3) New civilian signal –
The GPS IIF satellites carry the first operational civilian signal, L-5, a protected, high-power, wide-bandwidth signal used to assist commercial aviation activities and safety-of-life applications. Aircraft will use the signal to improve positioning and navigation accuracy and boost safety, capacity and fuel efficiency.
Beyond transportation, L-5 will provide users worldwide with the most advanced civilian GPS signal that, when used with other civilian signals, can enable sub-meter accuracy and longer-range operations.
4) Longer design life for reduced operating costs –
GPS IIF satellites are designed to last 12 years on-orbit, and longer operational life means lower operating costs. The IIF satellites will form the backbone of the constellation for the next 15 to 18 years.
Past system performance indicates that the satellites could likely last much longer. Approximately a dozen Boeing-built GPS IIA satellites are still in operation, some lasting two or three times longer than their original design lives.
The entire GPS constellation is controlled by the Operational Control System. OCS has had no interruptions of service or mission since activation in 2007. OCS has improved operations, increased efficiency and provided a foundation for new capabilities, such as the Selective Availability Anti-Spoofing Module, which provides security against fake satellite signals.
Source: Space Daily