It is for locating mineral deposits in the ground. We are in the midst of a gold boom up here and we have those things flying around constantly. They are either under a helicopter or towed behind a plane.
That looks like the OPP chopper. I saw it today flying near Highway 9 and the 10th Sideraod, which is south of Beeton. It was around 4:30 pm and I didn't notice anything hanging from the chopper at that time. Very Curious.