There is growing concern regarding the ability of GPS receivers to operate in the presence of in-band or nearband interference. In-band interference can occur deliberately from GPS jammers or naturally from spurious harmonics from nearby electronics that generate signal products that land in the GPS signal band. To support development and testing of GPS receivers in an interference environment,...

The goal of the U.S. Department of Transportation (DOT) Global Positioning System (GPS) Adjacent Band Compatibility Assessment is to evaluate the adjacent radiofrequency band power levels that can be tolerated by GPS and Global Navigation Satellite System (GNSS) receivers and to advance the Department’s understanding of the extent to which such power levels impact devices used for transportatio...

This paper presents the design of a dual-band microstrip antenna with low wide-angle axial-ratio. The antenna is designed for global positioning satellite operations at 1227MHz (L2), 1575 MHz (L1) and 1176 MHz (L5, available after 2007). This antenna has another advantage of a much wider band in both VSWR and 3 dB axial-ratio compared with single-fed GPS antennas. Details of the design, simulat...

Intentional or unintentional interference and jamming is one of the major concerns in using the Global Positioning System (GPS) in various critical applications. In spite of the GPS frequency bands being protected by International and Federal Communication Commission (FCC) frequency assignments, there is always a chance of disruption of the GPS signal availability in critical times and applicat...

The Global Positioning Systems (GPS) and Inertial Navigation System (INS) technology have attracted a considerable importance recently because of its large number of solutions serving both military as well as civilian applications. This paper aims to develop a more efficient and especially a faster method for processing the GPS signal in case of INS signal loss without losing the accuracy of th...

We investigate the characteristics of ionospheric scintillation across the entire GPS frequency band spanning the L5–L1 carrier signals (1176 MHz–1575 MHz). Of particular interest is the intensity correlation between carrier pairs, since this dictates the extent to which frequency diversity may be leveraged to mitigate scintillation impacts on navigation accuracy. Since only a few satellites cu...

The Global Positioning System (GPS) signals are very weak signal over wireless channels, so they are vulnerable to in-band interferences. Therefore, even a low-power interference can easily spoof GPS receivers. Among the variety of GPS signal interference, spoofing is considered as the most dangerous intentional interference. The spoofing effects can mitigate with an appropriate strategy in the...

Monitoring results are presented for the Stangellini 1 Jy GHz-peaked-spectrum source sample, illustrating that several members exhibit variability in total flux and/or linear polarization over timescales of order a decade. The variability occurs while the spectrum, based on the integrated fluxes, remains steep and characteristic of a transparent source. Total flux variability is unexpected in v...