LAUSR

The Global Positioning System (GPS) provides satellite-based navigation signals, which are employed in many fields, including agriculture, transportation, aviation, and military/personal navigation. In an effort to minimize interference among GPS satellites and to enable GPS receivers to discern satellite identity, each satellite is assigned a specific pseudorandom noise (PRN) sequence that is used to modulate the phase of the corresponding signal. The codes that modulate the current GPS landscape are constructed in such a way that cross-correlation among codes is kept to a bounded minimum, which should significantly limit harmful signal interference. In this study, the efficacy of the current PRN-based modulation system is called into question as GPS signal amplitude and carrier phase data over the past decade show frequent interference between satellite signals.