Scantherma has expertise in the use of Radar datasets and their applications towards mining and exploration. We have successfully generated niche datasets helping geologists in areas ranging from equatorial Africa, South America and South-East Asia.
In recent years, the use of Radar imagery with application towards mining and exploration has increased tremendously. This is because in many cases geologists have target areas in tropical locations with persistent cloudy conditions, and often have limited access to detailed topographic models and DEMs. This is where Radar imagery helps. Please click on the following links to find out more on how Radar imagery could be useful for your mining and exploration project.
Benefits and Limitations of using Radar Imagery
Radar is an example of an active Remote Sensing system. Radar uses relative long wavelengths which allow the sensor to “see” through clouds, smoke, and some vegetation. This makes a fantastic tool in obtaining imagery for tropical areas which would otherwise have persistent cloud cover, prohibiting the collection of traditional satellite imagery. Also, being an active system, Radar sensors can collect imagery both through the day and night, meaning quicker collection times.
There are disadvantages to Radar imagery as well. These would include the non-unique spectral properties of the returned radar signal. This means that unlike infrared data that help us to identify different minerals or vegetation types from reflected sunlight, Radar sensors only show the difference in the surface roughness and geometry of a surface. Additionally, due to their complexity, Radar imagery often requires extra processing and filtering for adequate results to be obtained, which means that sometimes the cost is more expensive than comparative optical sensors such as regional satellite imagery.
Please don’t hesitate to contact Scantherma if you have further questions regarding using Radar imagery for your mining and exploration applications.
Applications for Mining & Exploration
The most useful Radar bands for mining and exploration applications are X, C and L frequencies. In most cases, these frequencies have the ability to not only pass through forest canopy, but they can also penetrate dry top soil in deserts to reveal striking underlying geology. This makes Radar imagery excellent for recognising the following geological features:
- Regolith mapping. Extent, and relevance towards regional geology and geomorphology
- Fault and lineament identification and mapping
- Analysis of folds and curvilinear features. Particularly important in low-lying terrain where surface features are often too subtle for immediate identification
- Paleo-channel mapping in arid regions. This is particularly important to diamond and uranium exploration.
Additionally, some stereo-capable Radar sensors allow for the generation of DEMs in areas where persistent cloud cover is a problem for optical satellites such as in equatorial regions. This can be achieved through a process called interferometry. This is a very important product since in many tropical areas, geologists often only have very coarse DEMs and topographic models to work with.
The following table shows the frequencies of the most popular Radar sensors
| Sensor | Resolution Range | Frequency | Stereo Capable |
|---|---|---|---|
| Radarsat 2 | 3m to 100m | C-BAND (5.4cm) | Yes ~10m |
| JERS | 18m | L-BAND (23.5cm) | No |
| PALSAR | 7m | L-BAND (23.5cm) | No |
| COSMOS | 1m to 100m | X-BAND (3.1cm) | Yes ~5m |
Radar and infrared sensors are complimentary instruments, often used together to study the same types of earth surfaces. Scantherma recommends that Radar be used in conjunction with passive satellite imagery for use in the mining and exploration industry. For example, this may include capturing the same area using ASTER or Worldview-2 to further investigate surface reflectance values and for the construction of natural colour and enhanced colour imagery.
Examples of Radar imagery for mining and exploration use:
Radarsat 2 image over an important pot ash mining area in the Republic of Congo. The dataset was captured in stereo mode, thus allowing for the output of a 10m DEM.
PALSAR image of western Guyana. The imagery was used to identify geological features such as faults and regolith in the subtle, low-lying terrain.
COSMOS image highlighting extensive fault systems in the Andes mountains of Peru. These faults are associated with the discovery of mineral deposits such as gold, copper and silver.
