Abstract: A transmission measurement system for a guided surface wave transmitted by a guided surface waveguide probe, wherein the transmission measurement system includes at least one mobile metering device configured with a mobile 3-axis antenna and a plurality of sensing subsystems to continuously sense and measure a plurality of meter measurement data while being conveyed by a ground-based or airborne vehicle, the plurality of meter measurement data include but is not limited to the electromagnetic field strength of the guided surface wave, the weather and atmospheric conditions local to the mobile metering device, and soil sigma measurements selected from at least estimated soil sigma measurements and direct soil sigma measurements along the path of the mobile metering device.