A Novel Passive Tracking Scheme Exploiting Geometric and Intercept Theorems

Area of Science:

• Wireless Sensor Networks
• Signal Processing
• Localization and Tracking

Background:

• Passive tracking, or device-free target tracking, is an emerging field in wireless sensor networks.
• Radio Frequency (RF) Tomography schemes, particularly those using geometric theorems (GTs), are popular for their ability to reduce the need for high node density.
• Existing GT-based methods estimate target crossing points (CPs) on line-of-sight links (LOSLs) to determine trajectory.

Purpose of the Study:

• To review existing geometric theorem (GT)-based passive tracking schemes.
• To propose a novel passive tracking scheme leveraging the Intercept Theorem (IT).
• To develop a method for estimating CPs in noisy, non-parallel LOSL situations.

Main Methods:

• Exploitation of the Intercept Theorem (IT) for passive tracking.
• Development of the equal-ratio traverse (ERT) method for IT-based CP estimation in challenging conditions.
• Experimental evaluation of GT-based algorithms, including the proposed IT scheme, under varying trajectories, node densities, and noise levels.

Main Results:

• GT-based tracking schemes demonstrate remarkable positioning accuracy, even with low wireless node density.
• The proposed Intercept Theorem (IT) scheme achieves finer tracking accuracy compared to other schemes.
• The IT scheme performs particularly well under conditions of lower node density and noisier topologies.

Conclusions:

• Geometric theorem-based passive tracking is effective for device-free target localization.
• The novel Intercept Theorem (IT) based scheme offers superior performance in challenging wireless environments.
• The proposed method enhances passive tracking capabilities, especially in scenarios with limited nodes and interference.