Abstract: A system and method of determining and reporting on the position of a wireless device relative to a group of other wireless devices dispersed within a specified geographic area. The system includes at least one Query Unit, three or more Responding Units disposed at determinable locations within the specified geographic area, and one or more Mobile Units, which may correspond to additional Responding Units or units that function only as receivers. The Query Unit sequentially queries the Responding Units, and, responsive to the respective query messages, the Responding Units transmit corresponding response messages. One or more of the Mobile Units receive the query and response messages, and generate, for each query-response message pair, a set of time-difference-of-arrival (TDOA) measurements, which are used by the Mobile Units to determine their positions relative to the Responding Units.

Abstract: A method and an apparatus that verify the correct operation and calibration of a wobbling coil CRT monitor landing adjustment jig. The video test signal and the wobbling coil signal are disconnected from the CRT under test. The invention receives the video test signal and the wobbling coil signal and generates a modulated video test signal by modulating the video test signal with the wobbling coil signal. The modulated video test signal simulates a correctly adjusted CRT or a CRT with a known amount of misadjustment regardless of the actual state of adjustment of the CRT under test.