Patent attributes
A system and method for providing a range (distance) measurement by measuring electromagnetic signal time of flight. The system provides an estimate of the quality of the range measurement by evaluation of the multipath environment based on signal characterization. In one embodiment, a received ultra wideband signal is evaluated by a scanning receiver to produce a channel scan waveform inclusive of the transmitted signal and multipath response. The channel scan waveform is evaluated for envelope rise rate, amplitude, leading edge direct path pulse time, saturation, blockage, and signal history characterization. Signal characteristics are used to determine a signal classification. Signals are then evaluated for quality based on the signal classification. In one embodiment, the signal quality is used to estimate a variance of the range estimate for use in navigation algorithms.