Patent ID: 8160497

Claim:
A method of determining conditions on the ground, comprising the steps of: dispersing an ensemble of microradios over the ground, each of said microradios including a rectifier, a capacitor to be parasitically powered, coupled to the rectifier, an oscillator coupled to the capacitor, a hysteretic switch coupled between the rectifier and the capacitor, a radiative structure coupled to both said rectifier and said oscillator to permit the charging of the capacitor in the microradio when a sufficient charge has been collected on the capacitor and then to discharge the capacitor to permit release of sufficient energy to power the microradio, whereby the microradios can be powered with relatively low levels of incident energy; providing said microradios with sensors; parasitically powering said ensemble of microradios; receiving the emissions from said microradios; and, demodulating the content thereof so as to record the parameters sensed by said sensors.