文档介绍：Nov 4, 2003 1 Outline of the Talk ? Introduction ? Signal Processing Primitives ? Tracking ? Target Classification ? Issues and Challenges ? Future Research ? Conclusions ? Remarks ? Discussion Nov 4, 2003 2 Introduction ? This paper – Outlines a framework for Collaborative Signal Processing (CSP) in WSN – Proposes detection and tracking algorithms – Implements and validates classification algorithms – Argues that CSP can address challenges with classification and tracking – Suggests CSP algorithms can benefit from ? Distributive processing: compute and transmit summary statistics ? Goal-oriented, on-demand processing: Only perform signal processing when a query is present ? Information fusion: “ The farther I am, the fewer details I need to know ”? Multi-resolution processing: Different tasks require different rates of sampling in space-time Nov 4, 2003 3 Signal Processing Primitives ? Detection – Computes running average of signal power over some window – Assumes noise is Gaussian – Calculates a CFAR threshold based on mean and variance – Event occurs when signal > CFAR threshold Nov 4, 2003 4 Signal Processing Primitives (2) ? Target Localization – Assumes isotropic, constant exponent signal attenuation model – Uses energy-based source localization techniques – Given 4 or more energy readings, uses non-linear least squares to find best fit (target location that minimizes error) ? Observation: Implicitly assumes calibrated and localized sensors Nov 4, 2003 5 Tracking of a Single Target ? Assumes a target enters through one of the corners ?“ Active ” cells: A, B, C, D ? Uses energy to “ detect ”? Algorithm – Nodes in cell detect target and report to manager – Manager estimates current target location – Manager predicts future position of target – Manager creates and initializes new cells – Manager hands off once the target is detected in a new cell Nov 4, 2003 6 Tracking of Multiple Targets ? In the simple case – Targets occupy disti