Low Cost Underground Monitoring System Using Radio Propagation Characteristics

This paper proposes the use of separated radio transmitter and receiver to determine underground monitoring system to detect ground structural changes. Some applications may require land monitoring to anticipate unwanted events such as land slide or intrusive construction. The ideas are to use low cost radio transmitter and receiver, and monitor propagation characteristics overtime so that unwanted event detected as propagation pattern disruption. In order to do so, multiple transmitters and receivers should be employed in fixed locations. This paper performs one transmitter one receiver site evaluation by recording the propagation pattern and simulates underground structure change by introducing a small metal box. Based on the measurement, structural changes can be detected by identifying received signal level pattern. Average signal decrement is 1.86 dBm or 2.68%.