Passive sonar de-noising for diver detection in presensce of snapping shrimp

Since 2010, TNO has conducted a number of experiments on passive diver detection in Dutch waters. We have demonstrated detection, localization and tracking of divers wearing open circuit and closed circuit underwater breathing apparatus as well as boats. However, until now, we have not conducted any such experiments in warm waters. The...

Passive acoustic detection of a rebreather using a random array

Divers, including closed circuit (rebreather) divers constitute a potential threat to waterside infrastructures. Active diver detection sonars are available commercially but present some shortcomings, particularly in highly reverberant environments. This has led to research on passive sonar for diver detection. Passive detection of open-circuit...

Passive diver detection and localization using hydrophones suspended under a boom

A boom is a line of floats that constitutes a physical barrier for providing abovewater stopping power. However, it does not provide any situation awareness. In order to overcome this shortcoming, an integrated “booms and sensors” solution using passive sonar was conceived and tested experimentally by suspending hydrophones under a boom. The...

Data fusion from multiple passive sonar nodes for target localisation and false alarm reduction

A PHD particle filter implementation has been detailed for the fusion of measurements from multiple passive sonar nodes. It has been demonstrated on simulated metadata and on experimental passive acoustic data of divers and small boats collected in an operational port environment. Fusion at the metadata level lowers the necessary data bandwidth,...

Recent Developments in SOBEK Passive Sonar Technology

Surveillance of waterside locations for protection against threats from small fast surface vessels and underwater intruders is a very relevant but challenging problem. For this reason, the Netherlands Organisation for Applied Scientific Research (TNO) is developing SOBEK – a family of passive sonar technologies for waterside surveillance. The...

Passive acoustic detection of closed-circuit underwater breathing apparatus in an operational port environment

Divers constitute a potential threat to waterside infrastructures. Active diver detection sonars are available commercially but present some shortcomings, particularly in highly reverberant environments. This has led to research on passive sonar for diver detection. Passive detection of open-circuit UBA (underwater breathing apparatus) has been...

Improving Protection Agains Intruders Using Passive Sonar

Divers and small vessels are increasingly recognized as a potential threat to high value assets. Harbour and waterside surveillance systems that are used to counter the threat of divers are usually based on active sonar, whose performance can be limited by reverberation in a harbour environment. Passive techniques are based on the detection of...

On the Advantage of Wideband Data Acquisition for Passive Diver Detection

Situation awareness is an important component of security that justifies the equipment of sites with monitoring systems. For shore/harbour security, these systems are mostly composed of camera and radar, to monitor the land and the water surface, and of active sonar(s) when the underwater situation is monitored. An alternate approach for...