A system to measure RF path loss in extreme environments
An understanding of the RF propagation channel is a requirement for designing successful RF communication systems. The RF propagation channel can be characterized by performing channel measurements, but this is, a problem for extreme environments since it is generally not economically reasonable to take expensive test equipment into such settings. For example, in potash mines the salt dust picked up in the mine becomes very corrosive when exposed to higher humidity levels on the surface. This paper describes a low-cost path-loss measurement system that is designed for extreme environments. The measurement system integrates a number of commonly available components. These include continuous-wave transceivers with a received-signal strength indicator (RSSI) output, a laptop computer with a 16-bit data acquisition card, and MATLAB, which is used to acquire the measurements. These measurements are then converted, using a MATLAB script and previously acquired calibration data, to relative power measurements in decibels. This MATLAB-based system quickly processes the raw results, producing calibrated results that can be viewed and compared at the time of the measurement. This measurement system was used to perform path-loss measurements in the 915 MHz ISM band at the Cory potash mine near Saskatoon, Saskatchewan. Some of these channel measurement results are presented in the paper.
path loss mines radio-wave propagation