First passive radar observations of auroral E-region irregularities

On August 27, 1998 we observed auroral E-region irregularities using the Ma nastash Ridge Radar system. These are the first radio science results from passive radar observations of commercial FM broadcasts near 100 MHz. These are also the first reported observations of 1.5 m irregularities in 15 year s. The data show scatter most consistent with type-1 and type-3 ion-acousti c turbulence as observed by 50 MHz and 140 MHz radars. The instrument is ex traordinarily low in cost and provides data free of range and doppler veloc ity aliasing problems. The range and velocity resolution achieved by this r adar is substantially superior to that of other comparable coherent scatter radars, and the time resolution is similar.