Improved approaches to airports, which significantly increase operational benefits and safety, are now being implemented even at remote locations where traditional ground-based services are unavailable. In some regions of the world, satellite signals are augmented, or improved for special aviation applications, such as landing planes during poor visibility conditions. In those cases, even greater precision operations are possible.
The good news for the aviation community is that GPS is being constantly improved and modernized. A main component of the ongoing civilian modernization effort is the addition of two new signals. These signals complement the existing civilian service. The first of these new signals is for general use in non-safety critical applications. The second new signal will be internationally protected for aviation navigational purposes. This additional safety-of-life civilian signal will make GPS an even more robust navigation service for many aviation applications.
The second safety-of-life signal will enable significant benefits above and beyond the capabilities of the current GPS services. The availability of this signal offers increased instrument approach opportunity throughout the world by making the use of dual-frequency avionics possible. Dual frequency means that errors that occur in the signals due to disturbances in the ionosphere can be significantly reduced through the simultaneous use of two signals. This will improve the overall system robustness, to include accuracy, availability, and integrity, and will allow a precise approach capability with little or no ground infrastructure investment.