GraCT: A Grammar based Compressed representation of Trajectories

Abstract

We present a compressed data structure to store free trajectories of moving objects (ships over the sea, for example) allowing spatio-temporal queries. Our method, GraCT, uses a $k^2$-tree to store the absolute positions of all objects at regular time intervals (snapshots), whereas the positions between snapshots are represented as logs of relative movements compressed with Re-Pair. Our experimental evaluation shows important savings in space and time with respect to a fair baseline.

arXiv commentThis research has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Actions H2020-MSCA-RISE-2015 BIRDS GA No. 690941

Cited by in corpus (6)

• GraCT: A Grammar-based Compressed Index for Trajectory Data
• Efficient Compression and Indexing of Trajectories
• A Grammar-based Compressed Representation of 3D Trajectories
• Faster and Smaller Two-Level Index for Network-based Trajectories
• Relative compression of trajectories
• About BIRDS project (Bioinformatics and Information Retrieval Data Structures Analysis and Design)