WASHINGTON — The US Defense Department is looking for alternatives to GPS, techniques that can provide positioning data without the vulnerabilities satellite communication entails. But while they’re waiting for the technology to arrive, companies are looking at techniques to help better guard GPS signals, for both military and commercial applications around the world.The two primary issues that companies are trying to sort out are jamming, where a powerful signal is used to disrupt a receiver’s ability to decipher the proper GPS link, and spoofing, where a system pretends to be another system.
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