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Showing posts from June, 2017

WiB - ultra wideband efficient UHF broadcast

[[Teracom]], inspired by earlier research{{cite journal|author1=Yiyan Wu|author2=Bo Rong|author3=Khalil Salehian|author4=Gilles Gagnon|title=Cloud Transmission: A New Spectrum-Reuse Friendly Digital Terrestrial Broadcasting Transmission System|journal=IEEE Transactions on Broadcasting|date=21 June 2012|volume=58, Issue: 3|pages=329 - 337|doi=10.1109/TBC.2012.2199598|url=http://ieeexplore.ieee.org/document/6222350/?arnumber=6222350|accessdate=25 June 2017|publisher=IEEE|issn=1557-9611}}, introduced a new system concept dubbed "WiB", that aims to improve [[frequency reuse]] in the [[Ultra high frequency|UHF band]] while at the same time enable savings in both operating power and capital expenditures costs.{{cite conference|author1=E. Stare|author2=J. J. Giménez|author3=P. Klenner|title=WIB – A new system concept for Digital Terrestrial Television (DTT)|conference=IBC 2016|date=16 March 2017|url=https://www.ibc.org/tech-advances/wib--a-new-system-concept-for-digital-terrestrial…

Why dash cams should be more widespread

Airplane scatter - talking through the sky

Airplane scattering (or most often reflection) is observed on VHF through microwaveshttp://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.pdfhttp://www.vk3hz.net/ae.htm

== Radio amateur usage ==

Compared to a single trail of [[Meteor burs…