Reflection Measurement of Fire Over Microwave Band: A Promising Active Method for Forest Fire Detection

This work presents a technique to detect forest fire using incoherent scattering of radio waves from the ionized electron cloud of combusting plant material. Superheated forest matter ionizes a certain amount of the Alkali salt in plants creating a natural plasma frequency. This work investigates this plasma using a calibrated transmission line to identify the electromagnetic plasma frequency of forest fire. A plasma frequency of approximately 500 MHz has been identified by burning 4 grams and 6 grams of dry Eucalypt leaves. The plasma frequency was found to be stable as long as the biomass density is constant.