Autonomy Artificial Intelligence Robotics (AAIR)

Sequential Satellite Lock (GPS-SL)

by Alberto Lacaze; Ray Wilhelm; Anne Schneider; Tanner Ray


This paper presents a new concept in GNSS navigation: Sequential Lock GPS (GPS-SL). The new concept and prototype provide a variety of advantages for robustness, solution maintenance, and jamming resistance. Under normal circumstances, GNSS receivers need to receive signals from four satellites simultaneously to get a fix on position and the receiver time bias. If three or less satellites are visible given the occlusions provided by the environment, or because someone/something is intentionally or unintentionally jamming the space, no benefit is provided to the navigation solution. In other words, four or more simultaneous satellites give you a fix, three or less simultaneous satellites usually do not contribute (with some caveats) at all.