Reconstructing Movement from Sparse Samples: Enhanced Spatio-Temporal Matching Strategies for Low-Frequency Data

TL;DR

Four modifications to the original Spatial-Temporal Matching algorithm for aligning the GPS trajectories to road networks are proposed: a dynamic buffer, an adaptive observation probability, a redesigned temporal scoring function, and a behavioral analysis to account for the historical mobility patterns.

Abstract

This paper explores potential improvements to the Spatial-Temporal Matching algorithm for aligning the GPS trajectories to road networks. While this algorithm is effective, it presents some limitations in computational efficiency and the accuracy of the results, especially in dense environments with relatively high sampling intervals. To address this, the paper proposes four modifications to the original algorithm: a dynamic buffer, an adaptive observation probability, a redesigned temporal scoring function, and a behavioral analysis to account for the historical mobility patterns. The enhancements are assessed using real-world data from the urban area of Milan, and through newly defined evaluation metrics to be applied in the absence of ground truth. The results of the experiment show significant improvements in performance efficiency and path quality across various metrics.

Figures (16)

• Figure 1: Retrieving candidate points and candidate edges for the GPS point $p_i$.
• Figure 2: An example of a candidate graph for a 3-point trajectory.
• Figure 3: How observation probability changes with distance for different $\sigma$ values.
• Figure 4: ST-Matching vs. Modified ST-Matching across efficiency metrics.
• Figure 5: ST-Matching vs. Modified ST-Matching across matching quality metrics.

Theorems & Definitions (8)

• Definition : GPS point
• Definition : GPS Trajectory
• Definition : Road Network
• Definition : Candidate Points
• Definition : Path
• Definition : Map Matching
• Definition : Path Reconstruction
• Remark