HELICOPTER TIME-DOMAIN ELECTROMAGNETICS AND MAGNETICS

Xcite™ is a new generation of helicopter-borne time-domain electromagnetic (HTDEM) systems, developed by New Resolution Geophysics (NRG™). The system has been commercially available since 2015 and is a proven and unparalleled alternative to existing HTDEM systems.

Key features of the system include:

• Innovative patented loop design
• Exceptional signal/noise
• The system is capable of field switching from a 25Hz to 12.5Hz.  A base frequency 12.5Hz data is advantageous in the higher conductance range while 25Hz data is perfect for less conductive targets.
• Programmable waveform with fast turn-off time.
• Logistically superior in setup and shipping. Rapid field setup time of only 4 hours.
• Mobilisation costs are reduced due to the compact size of the system when deflated.
• All raw, streaming data is recorded.
• The shock absorbing qualities of the frame results in a perfectly damped platform producing extremely quiet data.
• Low survey height of both transmitter, receiver and magnetometer results in significantly superior signal to noise ratios.
• Excellent depth of investigation.
• High performance in both early and late time.

INTRODUCTION

By incorporating the latest new-age, high speed electronics and sophisticated aeronautical engineering, New Resolution Geophysics (NRG™) has developed the next generation HTDEM system. The Xcite™ system provides a proven superior and efficient alternative to all prior HTDEM technologies. This has application for both mineral exploration and the geoscience mapping community. Additionally, the fast transmitter current turnoff and early channel sampling of Xcite™ is ideal for mapping typical aquifers.

The system has been continually updated and improved throughout the years with the latest update being a patented receiver suspension system. The improved suspension of the Xcite™ system resulted in a 2-to-10-fold decrease in noise levels, dependent on which base frequency is selected.

A patented inflatable bird has been developed as a carrier for the system. The transmitter loop diameter is 20 metres resulting in a programmable output power of up to 300,000 NIA.

The patented inflatable bird design was selected for several reasons, including:

• Ultra-compact size when deflated, resulting in optimal logistics in shipping. The direct result being reduced mobilisation cost and ease of mobilisation to remote locations.
• Fast set up time of approximately 4 hours
• The ideal combination of a robust structure, with flexibility while retaining a constant shape in flight, resulting in a stable and damped receiver platform.
• Minimal interference from microphonic noise.
• Less prone to damage than a conventional rigid or semi-rigid system.
• Extremely stable flight characteristics.
• Field repairable
• Innovative design

NRG has developed a propriety fast sampling and recording algorithm which allows the magnetic sensor to be mounted on the same plane as the EM transmitter bird. This unique configuration ensures that the magnetic sensor is close to the geological source resulting in a larger signal to noise ratio. Conventional systems house the magnetic sensor halfway between the helicopter and EM bird, causing significant loss of the magnetic signal.  Both the EM and magnetic sensors are at the same height AGL.

The low-level flying height of the combined Tx-RX and magnetometer results in higher resolution data due to:

• Saturation of targets due to the focused footprint of the Tx
• Anomaly amplitude due to the close proximity of the Rx to source
• Improved anomaly definition
• Improved spatial positioning
• Larger signal to noise ratios.