Long-time Slashdot reader schwit1 shares a Gizmodo report: Starting today, it appears the U.S. military will be testing a device or devices that will potentially jam GPS signals for six hours each day. We say "appears" because officially the tests were announced by the FAA but are centered near the U.S. Navy's largest installation, China Lake, Californi -- home to the Navy's 1.1 million acre Naval Air Weapons Center in the Mojave Desert. And the Navy won't tell us much about what's going on. The FAA issued an advisory warning pilots on Saturday that global positioning systems (GPS) could be unreliable during six different days this month, primarily in the Southwestern United States. On June 7, 9, 21, 23, 28, and 30th the GPS interference testing(PDF) will be taking place between 9:30am and 3:30pm Pacific time. But if you're on the ground, you probably won't notice interference.