Civilian Unmanned Aerial Vehicle Vulnerability to GPS Spoofing Attacks

The strength of the GPS signal on the earth´s surface averages-160 dBw. While many GPS receivers leave large space for signal dynamics, enough power space is left for the GPS signals to be spoofed. Spoofing is completely different from jamming. The objective of jamming is to simply interrupt the availability of the signal in space at the receiver. The effect is to cause the signal at the receiver to be corrupted so that no valid GPS signal can be decoded by the receiver. The goal of spoofing, on the other hand, is to provide the receiver with a misleading signal, fooling the receiver to use fake signals in space for positioning calculations. The receiver will produce a misleading position solution. While the GPS P-code is heavily encrypted and thus, is hard to spoof. The civilian GPS signal, is easy to spoof because the signal structure, the spread spectrum codes, and modulation methods are open to the public. The stability and predictability of GPS L1 signal are good, because: the frequencies, initial phase and C/A code for each level of modulation are stable, without frequency hopping which is frequently used in military radio communications.