UW Applied Physics Laboratory (APL)

Profiling the Ocean for Health

Expendable conductivity-temperature-depth profilers (XCTDs) record salinity and temperature profiles across depths to assess ocean conditions. These single-use devices often cost thousands of dollars per unit, creating an economic barrier for oceanographic research. This team developed Ion-XCTD: a lower-cost platform that preserves core XCTD functionality, integrating UW-APL’s recently developed ion-potential-based salinity sensor, a depth sensor, and a temperature probe. Ion-XCTD houses its embedded system in a waterproof enclosure and collects data as it descends via a spooled tether. The collected data is sent up the tether to a floating buoy where, it is wirelessly relayed to a remote receiver.