HOLONOMICALLY CONSTRAINED (TETHERED) SPIN-AROUND LOCATOR

摘要

An improved two-way tagging tracking and locating system uses time of arrival (TOA), Doppler, and angle of arrival (AOA) in conjunction with remote tags and a locator. The locator's antenna is tethered to a central point, and moved in a constrained motion so that it describes a roughly circular horizontal path. The locator transmits and receives sets of complex radio sequences to/from the tag(s) so that the tag(s) emit signals which are phase, chip, and symbol coherent with the received locator signals. This enables the locator to determine the distances and Doppler shifts between itself and the tag(s) at various positions in its path such that, by post correlation processing of complex captured signal sequences, aims a virtual phased array antenna at the tag(s), resulting in enhanced distance and direction measurements. The angular position of the orbiting locator's antenna may be measured using an electronic compass packaged with the antenna.

主权项

1. An enhanced distance and direction locator system, comprising:
at least one tag including an RF transponder operative to send and receive complex signal sequences; a locator unit including an antenna and an RF transmitter and receiver operative to send and receive complex signal sequences to and from the tag through the antenna; wherein the locator antenna spins on a tether of a fixed length so as to approximate a circle; a processor at the locator unit operative to perform post-correlation processing of the complex signal sequences to and from the tag to determine the distance and direction to the tag; and wherein the spinning antenna is used by the processor as a virtual phased array antenna aimed at the tag to enhance the distance and direction measurements.