UNDERWATER LOCALIZATION CHALLENGE INTRODUCTION

UNDERWATER LOCALIZATION CHALLENGE INTRODUCTION

Underwater localization is vitally important for underwater exploration and data gathering. However, since radio waves are severely attenuated by sea water, we have to operate in a GPS denied environment. In contrast, underwater sound travels with much lower attenuation and so we rely on acoustic systems to enable us to measure position. Whilst the slow speed of sound underwater is an advantage and enables us to measure propagation delays/distance very accurately, we must also overcome challenges posed by severe, time varying multipath effects (reverberation) and noise from many natural and man-made sources. This is an opportunity for teams to gain valuable, hands-on experience in how underwater acoustic systems work and collecting/processing acoustic data to estimate the location of a subsea device.

This year, participants in the localization challenge will be asked to locate a submerged miniature beacon using 1-way acoustic direction finding. The groups will be given an acoustic recording system and 3 hydrophones that they can configure as they wish to form a receiving array. The 3 hydrophone channels will be acquired simultaneously allowing time delays between signals arriving at each hydrophone to be estimated by correlating against the known signal transmitted by the beacon. Teams will take the receiver system out on a boat along with a GPS receiver and compass to gather georeferenced recordings from multiple locations. The teams will then analyse the collected acoustic data offline (or even while on the boat) to estimate the position, presenting their results/method on the final day of the workshop. The teams will compete on three aspects (1) a race to locate the beacon most quickly (2) the most accurate final position after post processing (3) the most innovative localization strategy. Experts will accompany the participating groups, during their preparation, data collection and analysis.