Date: Friday, February 6
Time: 12:00 noon - 1:00 PM
Location: ******* 3609 Engr. Hall *********
Speaker: Professor ROBERT NOWAK
Title: Estimating Spatial Fields Using Wireless Sensor Networks

Estimating Spatial Fields Using Wireless Sensor Networks

ROBERT NOWAK
ECE Department
University of Wisconsin-Madison

Sensor networks have emerged as a fundamentally new tool for
monitoring spatial phenomena. This talk will describe a theory and
methodology for estimating inhomogeneous fields using wireless sensor
networks. Inhomogeneous fields are composed of two or more homogeneous
regions (e.g., constant-valued, smoothly-varying, stationary Gaussian,
etc.) separated by boundaries. The boundaries, which correspond to
abrupt spatial changes in the field, are non-parametric 1-d curves or
2-d surfaces (in a 2-d or 3-d field, respectively). The sensors make
noisy measurements of the field, and the goal is to obtain an accurate
estimate of the field at some desired destination (typically remote
from the sensor network). The presence of boundaries makes this
problem especially challenging. There are two key questions: 1. Given
n sensors, how accurately can the field be estimated? 2. How much
energy will be consumed by the communications required to obtain an
accurate estimate at the destination? Theoretical upper and lower
bounds on the estimation error and energy consumption will be
discussed. A practical strategy for estimation and communication will
be presented. The strategy, based on a hierarchical data-handling and
communication architecture, provides a near-optimal balance of
accuracy and energy consumption.