Airplane scatter - talking through the sky
Airplane scattering (or most often reflection) is observed on VHF through microwaves http://www.nitehawk.com/w3sz/AircraftScatteron10and24GHzMUDv5a.pdf and, besides back-scattering, yields momentary propagation up to 800 km even in mountainous terrain. The most common back-scatter applications are air-traffic radar, bistatic forward-scatter guided-missile and airplane-detecting [[Bistatic radar|trip-wire radar]], and the US space radar. It is also a less common propagation mode used by [[Amateur radio operator|radio amateurs]]. == History == Airplane scatter itself had been invented in 1930, but HAM usage lagged until the late 80s. The advent of inexpensive [[Software-defined radio|SDR]] based and [[Tracking (commercial airline flight)|distributed real time flight tracking]] enabled precise scheduling, increasing feasibility. http://www.nitehawk.com/w3sz/W3SZ-NEW-AirCraftScatterNEWS2014.pdf http://www.vk3hz.net/ae.htm == Radio amateur usage == Compared to a single trail...