The Use of a Drone-Based Time-Domain Metal Detector to Locate Unknown Pipelines

A time-domain electromagnetic induction metal detector (TDEMI) was tested in conjunction with a drone, also known as an unmanned aircraft system (UAS), to identify buried metallic objects (ferrous and non-ferrous) at two sites on the RELLIS campus of Texas A&M University in Bryan, Texas. The airborne TDEMI instrument was newly released and is specifically designed by the manufacturer to be deployed by UAS. RELLIS, a former military airfield often used for research testing due to limited and controlled access, contains many unknown utilities from earlier uses. One test site was a 27-acre triangular section that previously included warehouses with related utilities. The other site was a one-acre rectangular section where a solar research site is planned. Site preparation work had begun on the smaller site when a previously unknown jet fuel line and valve were uncovered. The UAS test was expanded to cover this site to quickly map the location and extent of the jet fuel line within the solar project limits. The TDEMI instrument was able to identify the location of previously unknown pipelines at the large site as well as show the location and direction of a jet fuel pipeline at the planned solar site. The test results were used by facility personnel to advise the future design for the site. In addition to detecting metallic pipelines and utilities, the TDEMI system can detect and map underground storage tanks and other buried metallic features. The application of the technology on a UAS platform makes the TDEMI system deployable in areas where land-based data collection is not optimal. A discussion of the advantages and disadvantages of the use of UAS-based TDEMI operation is further discussed.