A strategy is presented for exploiting the frequency stability, transmit location, and timing information of ambient radio-frequency “signals of opportunity” for the purpose of navigating in deep urban and indoor environments. The strategy, referred to as tightly-coupled opportunistic navigation (TCON), involves a receiver continually searching for signals from which to extract navigation and timing information. The receiver begins by characterizing these signals, whether downloading characterizations from a collaborative online database or performing characterizations on-the-fly. Signal observables are subsequently combined within a central estimator to produce an optimal estimate of position and time. A simple demonstration of the TCON strategy focused on timing shows that a TCON-enabled receiver can characterize and use CDMA cellular signals to correct its local clock variations, allowing it to coherently integrate GNSS signals beyond 100 seconds.

Cite and download the paper:
Pesyna, Jr., K.M., Z.M. Kassas, J.A. Bhatti, and T.E. Humphreys, "Tightly-Coupled Opportunistic Navigation for Deep Urban and Indoor Positioning," Proceedings of ION GNSS, Portland, Oregon, 2011.

Download the presentation here [pptx].