Category Archives: Engineering

Skidaway Institute radar system restored after Hurricane Matthew

Gabe Matthias

Gabe Matthias

UGA Skidaway Institute of Oceanography’s WERA radar system is back on line after being knocked out by Hurricane Matthew, and Dana Savidge is crediting research technician Gabe Matthias for the accomplishment.

Savidge’s lab operates two low-power radar installations, one at the Villas by the Sea Resort on Jekyll Island and the other on the beach at the north end of St. Catherine’s Island. The radar system monitors the speed and direction of surface ocean currents on the continental shelf.

Both installations went down due to power failure during the early October storm. The St. Catherine’s installation was off-line the longest, but it was actually the easier fix. It was relatively undamaged, but power wasn’t restored to the north end of the mostly uninhabited island until December. Matthias said when he visited the St. Catherine’s site after the storm, the power was still out. He removed some debris and straightened the antennas, and then used a back-up power supply to test the equipment.

“It ran out of juice quickly, so I had about 10 seconds to look at the return and see that it all looked good,” he said. “I was psyched and like ‘It’s all here. St. Catherine’s will be just fine.’”

The installation on Jekyll Island was another story. The antennas were mounted on a beachside boardwalk and on the adjacent beach.

A radar antenna mixed with hurricane debris at Jekyll Island.

A radar antenna mixed with hurricane debris at Jekyll Island.

“When I got there, I could see we were in trouble,” Matthias recalled. “Three of the four antennas on the sand and several on the boardwalk were knocked down and rolled up in all the rack, logs and seaweed, and shoved up into the dunes to the new high tide line.”

Matthias spent several days just cutting through the debris to recover the antennas and cable. One antenna was completely buried. Matthias only located it because he was able to trace the cable that was sticking out of the sand. Eventually, he was able to repair seven of the 12 receive antennas and two of the four transmit antennas. When power was restored, the installation went back online but with limited capability, pending the delivery of replacement parts.

“I was hooting and hollering and screaming for joy when I got the Jekyll Island installation back online,” Matthias said.

Savidge praised Matthias for his work. “Gabe did a great job under trying circumstances. I can’t say enough about his energy and dedication.”

 

Georgia Tech-UGA Skidaway Institute grad student defends dissertation

OLYMPUS DIGITAL CAMERACatherine Edwards’ Ph.D. student, Dongsik Chang, successfully defended his dissertation July 11th in the Department of Electrical and Computer Engineering at Georgia Tech. His dissertation was titled “Motion Tomography Performed by Underwater Mobile Sensor Networks.” He was co-advised by Catherine and Fumin Zhang of Georgia Tech.

Dongsik started his Ph.D. work in 2010 at the Georgia Tech Savannah campus, and began work with Catherine in 2011 for the NSF-funded Long Bay project. He developed the GENIoS (Glider Environment Networked Information System), which optimizes navigation of gliders based on information from real time model and observational data streams like HF radar, satellites, and operational ocean models. Dongsik’s dissertation defense focused on the concept of “motion tomography” pioneered by the Skidaway Institute/Georgia Tech glider lab. Similar to medical CT, which reconstructs 3-D images of objects, glider motion tomography uses the displacement of a glider by currents to reconstruct features of the flow field.

“His work bridging oceanography and engineering has been demonstrated to improve the quality of the data that can be collected by gliders, and has major implications for generalized fleets of autonomous underwater vehicles,” Catherine said. “Congratulations, Dongsik!”