Penetration Depths

The depth penetration of radiowaves is dependant on the frequency used and the composition of the medium under investigation. Lower frequency (e.g. 400 MHz) antennae achieve greater depth penetration than higher frequency antennae (e.g. 1500 MHz) but their resolution is lower than that of a higher frequency antenna. The choice of antennae frequency is dependant on the investigation objectives. This in turn, will determine the width of survey path, for example, an antennae frequency of 400 MHz has a 0.3 m survey path width. At Sandberg, a range of antennae are utilised, the most common include:

Investigations are also undertaken using lower frequency antennae (200 – 16 MHz). Maximum penetrations depths vary according the subsurface media but can reach as deep as ~30 – ~40 m. Examples of potential use include detection of groundwater tables, depth to bedrock, mapping of landfills and commercial assessment of sands and gravels in glacial landforms.

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