Very Low Frequency Method Combined with an Unmanned Aerial System

So called Unmanned Airborne Systems (UAS) can be used beneficial for geophysical measuring campaigns. Their advantages reach from faster data acquisition compared to ground measurements to higher versatility (e.g. ground vicinity) to conventional aerial systems. The geophysical Very Low Frequency (VLF) method exploits this advantages especially good. This is because it is well suitable for mapping and therefore extremely powerful in combination with aerial systems. The system presented here is a combination of the unmanned helicopter Scout B1-100 from Aeroscout and the Super High Frequency induction coil Triple (SHFT) and Analog Digital Unit (ADU)-07 data logger from Metronix. The sensor and logger went trough a weight reduction process and had to be deployed on a special suspension developed by Aeroscout. With a payload of 18 kg and an operation time of one hour the system is ideal for mid sized measuring campaigns, i.e. several hundred meters. A proof of concept study was carried out in March 2012 on a test area close to Neuchâtel. Two man-made anomalies, a pipeline and a power cable were investigated to test the practicability of the system. The feasibility of airborne VLF measurements with an UAS to detect buried anomalies is demonstrated by first results.