L-3 Clinic 2007-2008
This page describes the efforts of the 2007-2008 L-3 Senior Clinic project team.
L-3 Communications Systems West funded a 2007-2008 University of Utah Department of Electrical and Computer Engineering Senior Clinic on the topic of angle-of-arrival (AOA)-based localization in wireless sensor networks. The technologies developed helped improve the effectiveness and accuracies possible with radio localization, and enable newer and less expensive localization systems.
This clinic advanced the state of the art in wireless sensor networks by improving our ability to perform indoor 3-D sensor location. Estimation of sensor location is a key first step in environmental monitoring applications, in which a large number of sensors are deployed across a large area, both for in-building and outdoor monitoring applications. In order to make use of the sensed data, we must know where the sensors are. Accurate 3-D localization is also critical in warehouse and factory floors, in which extremely low-power radio tags placed on boxes, parts, and equipment allows them to be located at all times.
This clinic team developed angle-of-arrival (AoA) measurement technologies using wireless devices, and improved distributed location estimation algorithms. The team investigated using multiple commercial wireless sensors with directional antennas pointed in different directions to estimate AOA. The team also investigated and implemented new distributed algorithms which use AOA measurements to improve location estimates.
As of April, 2008, the clinic team has implemented gain measurement on multiple directional antennas; angle of arrival estimation from gain differences; and position estimation based on RSS and AOA. In addition, a three-mote demonstration unit has been produced, and operates with the motes running the described code in a TinyOS / NesC environment. Below are the written technical outputs produced by the team:
Some helpful links can be found below:
This paper introduces the idea of using directional antennas to get AOA information.