Author Description

The accuracy and worldwide availability of the Global Positioning System (GPS) make it the dominant system for navigation and precise positioning. Unfortunately, many situations arise in which GPS may not be adequate, e.g., urban navigation. This research evaluates the navigation potential of the National Television System Committee (NTSC) broadcast signal using a time-difference-of-arrival (TDOA) algorithm. TDOA measurements are made using NTSC broadcast signals collected from low and high multipath environments. These measurements are then used to evaluate the severity and dynamic effects of NTSC broadcast multipath signals. Three data reduction algorithms were developed-one that modifies the classical cross-correlation TDOA approach, and two that difference the signals' time-of-arrival at each receiver. Each algorithm was evaluated for consistency and accuracy in each environment. Multipath mitigation was demonstrated using a locally fabricated antenna.