Evaluation of the potential for power line noise to degrade real time differential GPS messages broadcast at 283.5-325 kHz

The new Nationwide Differential Global Positioning System network uses the 283.5-325 kHz band to broadcast differential GPS (DGPS) correction messages. Concern has been expressed that power line corona and gap discharge noise could degrade the performance of DGPS receivers using this band. Previous work on power lines and the AM broadcast band identified corona and gap discharges as broadband noise sources in the LF/MF bands. The potential to locally degrade performance of DGPS receivers relatively close to some power facilities appears possible for certain situations. The extent of any DGPS interference problem will depend on receiver/antenna design and placement, signal strength, power line design, weather conditions, and characteristics of the noise source. Also affecting DGPS receiver performance can be the presence of any nearby nonpower line RF noise sources;such as electronic devices or equipment internal to the user's vehicle.