Field Test Validation Of Single-Element Antenna With Anti-Jam And Spoof Detection

As the utility of GPS continues to pervade (and upgrade) our daily activities, our increased reliance makes us more vulnerable to the inherent weaknesses of GPS. The incredible faintness and unencrypted nature of the GPS signal exposes it to both unintentional and intentional overwhelming, via mechanisms such as interference, jamming and spoofing (the broadcast of counterfeit GPS signals intended to deceive a GPS receiver). However some may argue that despite the great risk, the probability of a jamming or spoofing event is thankfully low. The argument may continue, that correspondingly few resources should be dedicated to protect against a low probability event. We attempt to resolve the tension between these high risk, yet low probability scenarios by establishing antenna designs that provide protection while exploiting existing infrastructure and equipment, thus requiring minimal additional resource dedication. In our previous work, we introduced a backward compatible single antenna design for GPS spoof detection [4] and anti-jam [5] for aviation applications. The proposed design required no additional signal processing blocks when in use with a standard GPS receiver and fit into the form-factor of a standard GPS antenna. In [4], we tested the proposed technique by combining simulated data with measured data to enable hardware-in-the-loop experiments, and in [5] we based our conclusions upon mathematical theory and simulation alone. This paper reports the results of a recent field trial where we were able to run hardware-in-the-loop tests to evaluate the performance of both our anti-jam and spoof detection techniques in response to jamming and spoofing attacks. In this paper we intend to validate our prior claims of achieving greater than 10 dB jam suppression and reliable spoofdetection when these threatening signals originate from below the horizon of the GPS antenna, making aerial platforms an ideal application.