Implementation of the L5 SBAS MOPS

Several L1 and L5 capable satellites are already on orbit and many more are launching soon. The operators of the various Satellite Based Augmentation Systems (SBASs) are actively investigating incorporating the new constellations and new signals. We have recently proposed new messages for broadcast on L5. These messages are intended for use in the Minimum Operational Performance Standards (MOPS) and are designed to allow SBASs to communicate corrections and integrity information to the aircraft. Specifically, they allow the use of L1 and L5 in combination to achieve better performance than today’s use of L1-only. The proposed L5 messages were designed to make better use of the limited data bandwidth between the SBAS geostationary satellites and the aircraft. In particular, they are intended to allow for the simultaneous correction of at least four constellations of navigation satellites. This paper evaluates real satellite clock and orbit performance data and implements both the existing and proposed MOPS message formats. It then demonstrates the benefits of the proposed messages. It further demonstrates the new message structure’s capability to handle satellite alerts. It provides a practical demonstration of functionality of the new message structure including the improved bandwidth capability to handle multiple constellations.