Patent ID: 8547225

Claim:
A mobile platform comprising: an antenna for converting a plurality of signals received from a plurality of signal sources remote from the platform along a plurality of paths into electronic data representing the received signals; a receiver coupled to receive said electronic data representing the received signals from said antenna and programmed with software that measures characteristics of the received signals, wherein said receiver outputs electronic data representing measured values of said characteristics of the received signals; a computer coupled to receive said electronic data representing measured values of said characteristics of the received signals from said receiver and programmed with software that: (a) processes said electronic data representing measured values of said characteristics of the received signals to determine whether or not said characteristics of the received signals include anomalies indicative of volcanic gas-induced refraction effects produced during propagation of the received signals along said paths; and (b) issues an activation signal when said characteristics of the received signals include said anomalies; and an alarm device which generates a perceptible alarm in response to receipt of said activation signal.