Marine exploration sensing with light and sound

March 13, 2018, King Abdullah University of Science and Technology
Marine exploration sensing with light and sound
KAUST researchers are modeling various techniques for improving wireless underwater sensor networks. For example, new wireless hybrid sensors that use both acoustic and optical communication could improve underwater data collection for ocean observation. Credit: © 2018 Abdulkadir Celik

Oceanic sensor networks that collect and transmit high-quality, real-time data could transform the understanding of marine ecology, improve pollution and disaster management, and inform multiple industries that draw on ocean resources. A KAUST research team is designing and optimizing underwater wireless sensor networks that could vastly improve existing ocean sensing equipment.

"Currently, underwater use acoustic waves to communicate data," explains Nasir Saeed, who is working on a new hybrid optical-acoustic sensor design with colleagues Abdulkadir Celik, Mohamed Slim Alouini and Tareq Al-Naffouri. "However, while acoustic communication works over long distances, it can only transmit limited amounts of data with long delays. Recent research has also shown that noise created by humans in the oceans adversely affects marine life. We need to develop alternative, energy-efficient sensors that limit noise pollution while generating high-quality data."

One option is to use optical communication technology instead, but light waves will only travel short distances underwater before they are absorbed. Optical sensors also rely heavily on pointing and tracking mechanisms to ensure they are correctly orientated to send and receive signals. The team therefore propose a hybrid sensor capable of transmitting both acoustic and optical signals simultaneously. In this way, a data-collection buoy on the water surface can communicate with every sensor in a network spread out beneath it.

However, marine research requires accurate measurements taken from precise locations, so scientists need to know where every sensor is at any given time. The team used mathematical modeling to develop a proof-of-concept localization technique.

"Using our technique, the sensors transmit their received signal strength information (RSSI) to the surface buoy," says Saeed. "For a large communication distance, the sensors use acoustic signals, but if the sensor is within close range of another sensor, it will send an optical signal instead."

Multiple RSSI measurements for each sensor are collected by the surface buoy. The buoy then weights these measurements to give preference to the most accurate readings before calculating where each sensor is positioned.

Alouini's and Al-Naffouri's teams propose that their sensors will require a new energy source rather than relying on short-term battery power. They envisage an energy-harvesting system that powers fuel cells using microscopic algae or piezoelectric (mechanical stress) energy.

Explore further: Underwater sensor successfully tested

More information: et al, Energy Harvesting Hybrid Acoustic-Optical Underwater Wireless Sensor Networks Localization, Sensors (2017). DOI: 10.3390/s18010051

Related Stories

Underwater sensor successfully tested

June 5, 2013

As part of the Dutch STW SeaSTAR project researchers at the University of Twente have conducted tests using underwater communication and location finding at the Rutbeek water recreation park near Enschede. The aim of the ...

High-speed communication systems based on ultraviolet radiation

December 12, 2017

Military and civil authorities could benefit from secure optical communication systems that use light to carry messages between moving vehicles. Researchers at KAUST have now demonstrated rapid data transfer using ultraviolet-B ...

Pencil test for pipeline cracks

June 8, 2016

It is impossible to see when the "lead" in a pencil cracks within the pencil, but an acoustic sensor can "hear" the change in the way the pencil vibrates. Now, researchers in China have reported in the International Journal ...

Recommended for you

1 in 3 Michigan workers tested opened fake 'phishing' email

March 16, 2018

Michigan auditors who conducted a fake "phishing" attack on 5,000 randomly selected state employees said Friday that nearly one-third opened the email, a quarter clicked on the link and almost one-fifth entered their user ...

World's biggest battery in Australia to trump Musk's

March 16, 2018

British billionaire businessman Sanjeev Gupta will built the world's biggest battery in South Australia, officials said Friday, overtaking US star entrepreneur Elon Musk's project in the same state last year.

Origami-inspired self-locking foldable robotic arm

March 15, 2018

A research team of Seoul National University led by Professor Kyu-Jin Cho has developed an origami-inspired robotic arm that is foldable, self-assembling and also highly-rigid. (The researchers include Suk-Jun Kim, Dae-Young ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.