M-CTX: Exact and Scalable Spatial Context Retrieval for Trajectory Analytics

In three linesM-CTX is a spatial context-retrieval framework for trajectory analytics. It replaces three brute-force stages (OSM range retrieval, SDF computation, moving-vessel neighbor lookup) with index-backed operators. On a 5.48M-anchor maritime corpus, it reduces context construction from 17 CPU-days to 1.8 hours (226x speedup), with exact reproduction of reference context.

Summary generated by Claude — human-verified