Our receivers can measure field strengths that vary greatly in magnitude, from weak, naturally occurring magnetotelluric signals to strong CSEM signals. And, highly precise signal timing enables us to measure the EM phase with respect to the source.

For accurate seabed positioning, the receivers are designed to descend rapidly; to enable large surveys to be performed, they can remain autonomous for weeks.

So that we can perform large and efficient surveys, we have invested in not only receiver technology but also purpose-built 3D EM vessels, which are designed to handle large numbers of receivers efficiently.

Key features

  • Comprehensive field measurement for shallow water surveys with four electric (E) and two magnetic (H) channels that record vertical and horizontal field components
  • Large dynamic range that enables high-resolution data to be recorded at all source–receiver offsets without signal saturation, thanks to data loggers with 24-bit analogue-to-digital converters and automatic gain control
  • Low signal-to-noise ratio. Each electrical sensor pair is held 8 m apart on arms that are vertically flexible to minimise drag on descent but that are stiff in the horizontal direction.
  • High sensitivity makes the receivers suitable for magnetotelluric  and CSEM surveys, as they can detect weak electric and magnetic fields
  • Accurate synchronisation of the received signals and the source waveform using GPS time-reference signals backed up by on-board clocks
  • Fast placement and minimum footprint through concrete anchors that use patented soluble cement. The anchors provide rapid sink rates for accurate placement and offer a stable noise-limiting platform. The anchors remain on the seabed after the receivers are retrieved. The cement dissolves, which reduces the concrete to disaggregated sand in six to nine months to ensure no seabed hazards remain after this time.
  • Long seafloor life for large CSEM surveys and magnetotelluric surveys, thanks to proprietary electronics that combine low noise levels for high sensitivity with low power consumption, long battery life and a large-capacity memory