Profile

Browse more profiles
Meet Martin Siderius
Meet Martin Siderius

 

Martin Siderius, Ph.D., Professor, Electrical and Computer Engineering
ASA Fellow and Director Northwest Electromagnetics and Acoustics Laboratory (NEAR-Lab)
http://nearlab.ece.pdx.edu/index.html

Since electromagnetic signals do not travel very far in the ocean, acoustics are the best substitute for sensing in the underwater environment. For example, using optics, it might be possible to see objects underwater at distances of tens of meters but not much beyond. Exploring the depths of the ocean may require probing over thousands of meters which leads to acoustic systems which can propagate over these distances. Using systems similar to terrestrial technologies such as cellular phones, GPS and WiFi networks underwater requires using acoustics and this can be extremely challenging. Remote sensing above ground uses electromagnetic signals (e.g., radar) for applications like Google Earth and weather forecasting images. Similar sensing systems for mapping the ocean floor or predicting ocean currents requires acoustic remote sensing (sonar). There are very important differences between electromagnetic and acoustic signals such as the speed of propagation. The speed of light is air is 3x108 m/s while sound travels at 330 m/s in air and 1500 m/s in water. Delays between acoustic transmission and reception can be problematic; particularly for two-way communications. For example, terrestrial cell phone conversations over 15 km or 150 km are as natural as sitting in the same room; however, using a 15 km acoustic link underwater introduces a 10 second delay. Another difference is the limited spectral bandwidth that can practically be used for sensing due to the attenuation of signals in the ocean. While a 10 kHz acoustic signal has an attenuation factor of only about 1 decibel per kilometer a 100 kHz acoustic signal has an attenuation factor of about 100 decibels per kilometer.

Siderius has recently implemented acoustic systems on underwater vehicles. Aerial drones are becoming increasingly attractive in replacing activities traditionally done with airplanes. Similarly, underwater drones are being seen as an alternative to survey ships for ocean exploration. However, due to the inherent difficulty in communicating with underwater drones, the operations for remote sensing are still rudimentary. One of the applications of underwater vehicles is in the study of marine life. A variety of marine mammals use sound for navigation and communication. These signals can be recorded and analyzed to determine species and population densities. Siderius has been developing acoustic recording capabilities on underwater vehicles to estimate marine mammal population densities.

Siderius’ teaching and research focuses on topics related to acoustics, electromagnetics, sensing and signal processing. Prior to his faculty appointment at the Maseeh College, he was Vice-President and Principal Scientist at HLS Research Inc., a startup company he co-founded in 2004. HLS Research is dedicated to applied and basic research on wave propagation phenomena. Siderius spent three years as a Senior Scientist at the Science Applications International Corporation. From 1996-2001 he was on the scientific staff of the NATO Undersea Research Centre in La Spezia, Italy. Siderius has a B.S. degree in physics from Western Washington University and M.S.E.E. and Ph.D. degrees in electrical engineering from the University of Washington.

For more information, please contact the Department of Electrical and Computer Engineering at the Maseeh College:

Phone: (503) 725-3806
Email: info@ece.pdx.edu
www.ece.pdx.edu
https://www.pdx.edu/ece/siderius