Constructing an efficient state space query system for the voyage data recorder.

Abstract

Voyage data recorders are devices kept on vessels to track their trajec-tories when overseas. It receives signals from global positioning satellites to compute its current location on Earth and records the current speed, course, and bearing within its internal memory. The information is downloaded and recorded each time the fishing vessel docks for fueling. Currently, over 10 thousand devices are installed and tracked, collecting over 3 billion GPS samples over 8 years period. This paper presents our approach to clean and reorganize the data, and design an efficient incremental updatable database for fast query on the state of vessels and the spacial locations of vessels. We have also adapted the WebGL technology for visualization of trajectories with more than 100 thousand points. The initialization of this work will provide a better platform for future fisheries management such as resource estimation, catch per unit effort analysis, environmental protections, operational efficiency, and activity surveillance.