Fiber-Optic Distributed Temperature Sensor

Mason Johnson, Graduate Student
Troy Gilmore, Faculty Advisor

Fiber-optic distributed temperature sensing (FO-DTS) has been used successfully to identify focused groundwater discharge for fluid sampling and vertical flux analysis (“informed measurements”). However, results from informed measurements have not been formally compared to discharge measurements made at pre-determined locations in the same reach (“uninformed sampling”). We deployed an FO-DTS cable along the left, center, and right sides of a small meandering sand-bed stream and found significant differences in groundwater discharge rate between informed and uninformed locations. Continue the story...

 

Assembled fiber-optic distributed temperature sensor

Assembled fiber-optic distributed temperature sensor (FO-DTS) on Gudmundsen Sandhills Research Laboratory near Whitman, NE. FO-DTS is a technique that uses fiber-optic cable deployed on a streambed to sense groundwater discharge into surface water.

Securing cables

Mason, graduate student in the School of Natural Resources, is securing fiber-optic cable on the streambed with cable fasteners to ensure the cable does not move with the water current.

Final Securing

Undergraduate student Sydney (left) and graduate students Mason (middle) and Marty (right) finish securing the cable on the streambed. Approximately 500 meters of fiber-optic cable was set on the streambed surface

measurement stream

This stream is located in a wet meadow valley in the center of the Sandhills of Nebraska. The photo was taken atop an outfall overlooking the Gudmundsen stream.

recording streambed temperature

Showing Sydney recorded streambed temperature data from the DTS system. Next, we will look for temperature anomalies in the data to locate areas of focused groundwater upwelling.

Pictures courtesy of Mason Johnson