Abstract: A system and method for discriminating and mitigating spoofing signals incoming to a satellite navigation system. Beam steering techniques are used to steer a null toward a legitimate satellite signal that is being spoofed. The spoofing signal is then tracked and its angle of arrival measured. A null is steered toward the measured angle of arrival of the spoofing signal, and the spoofing signal is confirmed by determining if there is a signal remaining with nulls on both the legitimate satellite signal and the spoofing signal. The null toward the legitimate satellite signal is then replaced with unity gain.

Abstract: A system and method for discriminating and mitigating spoofing signals incoming to a satellite navigation system. Beam steering techniques are used to steer a null toward a legitimate satellite signal that is being spoofed. The spoofing signal is then tracked and its angle of arrival measured. A null is steered toward the measured angle of arrival of the spoofing signal, and the spoofing signal is confirmed by determining if there is a signal remaining with nulls on both the legitimate satellite signal and the spoofing signal. The null toward the legitimate satellite signal is then replaced with unity gain.

Abstract: A system and method for testing the integrity of signals incoming to a satellite navigation system. The method is implemented with an array of antenna elements, and a receiver connected to each antenna element. The receivers simultaneously and continuously make measurements on all tracked signals. Each receiver measures the carrier phase of an incoming signal. Based on the carrier phase differences between antenna elements and the distance between them, the azimuth and elevation of the signal source can be calculated. This measured angle of arrival can then be compared to an expected angle of arrival to determine if the signal source is legitimate. The system and method can be also applied to determining the angle of arrival of sources of interference, and to mitigating the effects of both illegitimate and interfering signals.

Abstract: A system and method for testing the integrity of signals incoming to a satellite navigation system. The method is implemented with an array of antenna elements, and a receiver connected to each antenna element. The receivers simultaneously and continuously make measurements on all tracked signals. Each receiver measures the carrier phase of an incoming signal. Based on the carrier phase differences between antenna elements and the distance between them, the azimuth and elevation of the signal source can be calculated. This measured angle of arrival can then be compared to an expected angle of arrival to determine if the signal source is legitimate. The system and method can be also applied to determining the angle of arrival of sources of interference, and to mitigating the effects of both illegimate and interfering signals.

Abstract: A method for detecting the presence of a deception signal associated with a satellite navigation system. The deception signal has certain “observables”, which can be used by a GPS receiver to detect the presence of the deception signal.

Abstract: A method for detecting the presence of a deception signal associated with a satellite navigation system. The deception signal has certain “observables”, which can be used by a GPS receiver to detect the presence of the deception signal.

Abstract: A high-altitude airship has a non-rigid hull. On launch, the airship is partially inflated with a lifting gas. The partially inflated hull is less susceptible to buffeting and turbulence from lower atmosphere air currents during ascent. A ballast rotates the airship into a flight attitude (e.g., near horizontal) upon reaching a desired altitude. A low-powered propulsion system may be included to propel the airship at the desired altitude. Upon completion of its mission, the airship may be deflated and returned using aerodynamic deceleration such as a parachute, a parafoil and a ballute.

Abstract: A high-altitude airship has a non-rigid hull. On launch, the airship is partially inflated with a lifting gas. The partially inflated hull is less susceptible to buffeting and turbulence from lower atmosphere air currents during ascent. A ballast rotates the airship into a flight attitude (e.g., near horizontal) upon reaching a desired altitude. A low-powered propulsion system may be included to propel the airship at the desired altitude. Upon completion of its mission, the airship may be deflated and returned using aerodynamic deceleration such as a parachute, a parafoil and a ballute.