Loupe – Portable EM Profiling System (TX + RX)

The challenge was to develop a truly portable time-domain electromagnetic (EM) profiling system comprising both a transmitter and receiver unit. The system required ergonomic backpacks as each unit is required to be carried comfortably for extended periods of time. The TX + RX units needed to be non-conductive, protect operators from excessive magnetic fields and within ergonomic balanced target weights (approximately 12 kg each). The system needed to be operable, built to last in harsh conditions (windproof, dustproof, rainproof, and extended exposure to sunlight) and operate effectively in the presence of interference from power lines and other sources that traditionally degrade performance of EM instruments. The first scientific instrument from Loupe Geophysics required the development of a unique product design language to position the brand as a market leader and represent Loupe's high value offering.

Loupe is highly portable and able to measure practically anywhere a person can walk - highly effective in various types of terrain including through dense vegetation. To perform a survey, operators walk a specified set of lines at a constant pace to capture the conductivity response of the hemisphere of the ground beneath the operators. Backpacks used for Loupe are utilised for military applications in which heavier loads are worn comfortably for extended periods. Weight has been kept to a minimum - lightweight non-conductive structure (TX approx. 12 kg, RX approx. 10 kg). The transmitter (TX) loop is positioned behind the operator, to minimise exposure to excessive magnetic fields. Loupe comes pre-optimised with a range of standardised surveying settings, enabling inexperienced operators to undertake surveys. Incorrect adjustment of settings can cause unusable data. A design language developed for the Loupe system draws from ruggedised military/mining equipment and high-technology products. Loupe operates in temperatures -20 °C to +45 °C. Engineered to be resistant: rain, mist, windy + dusty conditions. Designed for continuous operation, enabling 15 to 20 km of data collection in a single day.

When mining iron ore, coal or base metals it is imperative operators know where the best material lies as well as the location of any hazards. Considerable effort is required in defining grades and hazards prior to, and during mining. A drill pattern to establish grade is common, even at very close spacing all the variability cannot be fully defined. The Loupe system can map between, and potentially below drill holes, to help define the extent of sulphide mineralisation; play cods in iron ore; volcanic intrusions in coal beds; or water-filled cavities. Sampling every metre along traverses gives Loupe a high spatial definition, assisting mining operations to identify risks, superior material locations and in-turn operate more effectively. The increased speed and accuracy at which Loupe enables electromagnetic surveying to occur at a lower labour cost opens the opportunity to pursue more rigorous investigations of geophysical activity in environmental, development, mining and discovery projects. Loupe semiconductors virtually eliminate electrical interference in EM profiling surveys and detailed 3D pictures of underground electrical activity ensure more accurate data for decision makers - geophysicists, landowners, industrial/mining operators and the community.

Time-domain EM methods afford good depths of investigation and can be used to create models of the subsurface conductivity distribution. Comparatively, standard ground-based moving loop approaches are relatively inefficient. These alternatives are typically towed behind an all-terrain vehicle, with use limited to tracks/some agricultural fields. Alternative airborne systems have high operational costs and are not suitable for all applications. Loupe is a state-of-the-art system using the latest in signal processing and motion detection hardware is a world first. The decision to develop the system was driven by frustration with available older EM systems and a clear market gap for a portable time-domain solution. The backpack mounted system with an in-built motion correction software drastically enhances surveying productivity and data quality. The system combines high spatial and depth resolution with fast acquisition rates. The range of depths of investigations far exceeds any alternative portable system that have been on the market for some decades.