GPX Airborne offer a range of electromagnetic surveying techniques.
When searching for mineralisation associated with massive sulphide mineralisation, electromagnetics can be very effective at scanning large areas of ground quickly for follow up ground targeting.
Airborne EM is also a favoured tool in environmental work when mapping palaeochannels in the search for water.
GPX has 3 techniques currently available including:
Each technique has a time based electromagnetic measurement over 21 channels. The later channels (~15ms) can give an indication of buried massive sulphides.
The cost of this technique is based upon the size of the survey in terms of line kilometers.
GPX Airborne offer a range of aeromagnetic survey techniques.
GPX Airborne have a variety of fixed wing and helicopter platforms available to suit any job, regardless of location or size.
In particular, the company offers:
- Fixed Wing Aeromagnetics Surveys
- Helicopter-Borne Aeromagnetic Surveys
Surveys are conducted to gather the best possible data for the client, whilst employing the safest and most practical methods of data gathering.
Airborne radiometrics is a measurement of the radioactive emission from the surface 30cm of the soil, which results from the natural decay of isotopes in the soil.
Airborne radiometric measurements have traditionally been obtained for four energy bands. These bands are indicative of total radiometric count, Uranium, Thorium, and Potassium. The data is usually obtained at an elevation of between 40 and 150m above ground level, with measurements about 50 – 60metres along flight lines. Flight line spacings vary with aircraft height above the ground from around 1.5km spacing at 150m elevation, to around 100m spacing at 50 – 80m elevation. Each measurement is split into 3 pixels across the flight line.
Emissions of gamma radiation from the land surface vary with many factors but essentially depend on the composition of radionuclides within 30cm of the soil surface. The composition depends on the parent material and the degree of breakdown, loss and/or accession, and therefore generally reflects parent material and weathering.
There are two main models or spectrometer:
Pico Envirotec GRS-410 Spectrometer
The GRS-410 Radiometric Data Acquisition System is an advanced spectrometer utilizing NaI detectors. It is a hardware-software design system, with advanced individual detector signal processing reducing the potential hazards (or complex circuitry) of "zero base shift" and practically eliminating "dead time".
The GRS-410 records real time calibrated summed 256 channel spectra. In addition, a “raw” 512-channel spectrum from each individual crystal is also recorded. This allows the data from individual crystals to be post-processed to achieve better energy calibration and as a result, a high-resolution 512 channel summed spectra.
| Specifications: | |
| Model: | Exploranium GRS-410 |
| Spectra Resolution: | 256 or 512 channels |
| Data Sampling: | Corrected 1.0 sec (512 ch) |
| Energy Spectra: | 50 keV to 3 MeV |
| Threshold: | Adjustable from 0 keV to 0.5 MeV |
| Cosmic: | Energies above 3 MeV are detected as Cosmic Rays |
| Spectra Tracking: | Individual detectors |
| Spectra Correction: | Automatic after system calibration |
| Dead time: | For normal detection rates negligible |
| Configuration(s): | 33.56 litres - 8 individual detectors in 2 boxes |
Exploranium GR-820 Airborne Spectrometer
The Spectrometer is an Exploranium GR-820 system. The unit comprises of 2 detector crystal packs, which give a total volume for detection of 33.4 litres. The spectrometer employs automatic gain stabilisation control to eliminate the need to heat the detectors. Signal processing automatically perform digital gain control to the individual crystal spectra, ensuring the summed spectrum is stable.
| Specifications: | |
| Model: | Exploranium GR-820 |
| Sensitivity: | 0 – 3.0 MeV |
| Maximum count rate: | 100,000 counts/sec |
| Detector volume: | 16.7 Litres (each) |
| Detector weight: | 83.9 kg (each) |
GPX Airborne offers airborne gravity as a service to the mining and exploration industry.
Canadian Micro Gravity GT-1A Gravimeter
The Canadian Micro Gravity GT-1A Gravimeter was developed by Gravimetric Technologies Ltd (Moscow) in collaboration with Moscow State University.
The GT-1A is an airborne, single vertical sensor, GPS-INS scalar gravimeter with a Shuler-tuned three-axis inertial platform. The gravimeter is attached to a platform that is horizontally stabilised at 300 Hz and is able to tilt up to 45 degrees (roll and pitch), allowing continual data acquisition even when the aircraft is cornering or during periods of turbulence.
Two channels of data are recorded simultaneously - a fine channel that operates within a vertical acceleration range of ±0.25g and a course channel that operates within a vertical acceleration range of ±0.50g.
| Specifications | |
| Model: | GT-1A |
| Range: | 9.76 to 9.84 m/sec2 |
| Range of accelerations: | 0.25g (fine range), 0.50g (course range) |
| Drift: | < 0.03 mGals/day |
| Error in gravity anomaly (RMS) | a) 0.01 Hz cut-off 0.6 mGals |
| b) 0.0125 Hz cut-off 1.0 mGals |
| Operating Temperature: | +5°C to +50°C |
| Vibration tolerance: | 0.2g (between 5 and 35 Hz) |
GPX also has a ground geophysics division offering a range of ground geophysical surveys. Information can be found on the following link.
GPX Ground Geophysical Surveys.
