Monex Geoscope TerraTEM24
The Wallaby and Wallaroo systems have been developed and comprehensively tested in production with AgTEM towed TEM electronics. During this process, many experiments were conducted leading to the conclusion that most towed TEM survey can be readily conducted with the more versatile Monex Geoscope TerraTEM24 with modifications that have gradually become facilitated, as options, after proof of concept was established on the AgTEM electronics.
The Monex Geoscope website describes the TerraTEM24 - it is purchased directly from Monex Geoscope rather than through Groundwater Imaging Pty Ltd.
When using the Monex Geoscope TerraTEM24 with Wallaby or Wallaroo the following options that largely were once only available with AgTEM towed TEM electronics are recommended:
1. Continuous acquisition (essential)
2. GNSS internal or external
3. Towed TEM continuous acquisition with mapping+sounding interface (highly reccommended)
4. External fan forced cooling (essential in most climates)
5. Variable output power 3.5V to 18V driven and regulated (as without this a bank of power resistors is needed and power is wasted requiring extra batteries)
6. Extra power regulation that allows use of the same batteries for loop power and electronics power
7. Dual logarithmic and full linear time gate stacked data storage for better noise post-processing (has never been available on AgTEM electronics)
8. Full waveform continuous data storage (only if you are willing to process this large volume of data - we have never attempted this and it is not available on AgTEM electronics)
9. As for with AgTEM electronics, a separate tractor guidance device is recommended for precision navigation guidance but the TerraTEM24 internal mapping facilities are sufficient for approximate steering guidance.
In contrast with AgTEM towed TEM electronics, the TerraTEM24 is a single box instrument with large full metal case which cannot be positioned anywhere near any of the loops and even careless postioning of flying leads near the device can ruin towed TEM datasets especially with systems with loops that are close together. Being a large metal case single box it cannot be operated with Wallaroo in normal walk-mode but instead the TerraTEM24 must be carried by an extra person well away from the loops just like is essential with sTEM profiler systems. When used in the Wallaroo system with the electric tractor or a quad bike, positioning is on the metal vehicle a reasonable but very fixed distance from loops and this is suitable provided that system response is evaluated.
The second limitation of the TerraTEM24 is operational in that the touchscreen is on the box and there are limits to where the box can be positioned. In a vehicle it takes the entire passenger seat so training of operators is not feasible. If on a backpack one cannot see nor operate it without taking it off the backpack, and with Wallaroo it can only practically be carried on the towing vehicle. Talk to Monex Geoscope about getting a remote desktop protocol or other form of remote duplicated touchscreen as this is possible.
Stacked logarithmic timegate data from the TerraTEM24 can be read into our processing software.
Standard Wallaby/Wallaroo pre-amps can be supplied and optimized with TerraTEM24 systems so standard configuration applies.
To allow for our flexible transmitter loop turn swapping as used for moment changing and for system testing and diagnosis with our multi-wire transmitter loop cables we will provide an output panel for use with TerraTEM24 systems. Receiver loop connectors are compatible at the receiver loop end with Wallaby and Wallaroo receiver loops but differ at the TerraTEM24 end compared to AgTEM towed TEM electronics. We can supply suitable cables or adaptors depending on requirements.