Quasar Geophysical Technologies (QuasarGeo), based in California, has completed a set of three deepwater ocean verification tests of a prototype electromagnetic (EM) receiver. The company says the tests, conducted at depths of more than 1 km, all produced consistent data showing reproducibility of results and device reliability.

QuasarGeo built the EM receiver (the QMax EM3) with electrodes that do not need to be stored wet do not require long arms to obtain measurements. This contrasts with industry standard instrumentation which, according to the company, generally requires a baseline of up to 10 m to achieve adequate E-field sensitivity. The QMax is said to be able to achieve comparable sensitivity with a baseline of only 1 m, allowing for the construction of a compact, self-contained, easy-to-handle instrument. The complete unit can be loaded onto a ship and deployed without special handling to preserve the E-field electrodes’ functionality. In the three tests, data were environmentally noise limited, achieving industry-standard E-field sensitivity without use of long sensing arms.

The compact construction is designed to allow for vertical electric and magnetic field measurements equal to the horizontals. Technical challenges related to the length of E-field sensing arms and motion in the B-field measurements have made achieving this balanced measurement difficult in the past. Incorporation of equivalent vertical data into the processing offers the potential for better discrimination of the edges of structures. The data plot (below) details all six axes of QMax electric and magnetic field performance and shows this capability for vertical equivalence.