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en:vor [2019/04/06 12:14] – created fluktuacia
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 +FIXME **This page is not fully translated, yet. Please help completing the translation.**\\ //(remove this paragraph once the translation is finished)//
 +
 +====== Using VOR beacons for tracking flying objects ======
 +
 +[[https://en.wikipedia.org/wiki/VHF_omnidirectional_range|VOR radio bacons]] are a type of short-range radio navigation system for aircrafts, distributed evenly to cover most of the airspace. 
 +
 +By observing their signal, it was found out that the signal received on ground contains clearly distinguishable reflections from flying objects - see e.g. [[http://www.astrozor.cz/graphics/upload/reports/151-05.28.14-18_28_18.jpg|VOR beacon observation]] by station [[http://www.astrozor.cz/index.php?udalost=151|in Prague]]. 
 +
 +{{ :cs:vor:vor_airplanes.jpg?300 |}}
 +
 +{{ :cs:vor:vor.jpg?300 |}}
 +
 +Coordinates and frequencies of all existing VOR beacons can be found at webside [[http://ourairports.com/big-map.html#lat=0,lon=0,zoom=2,type=Hybrid|ourairports]] - check the navaids in map parameters.
 +
 +
 +===== Signal processing =====
 +
 +VOR beacons work at carrier frequencies in range 108 - 118 HMz. Sampling of this 10 MHz wide band should make it possible to process all beacons at the same time. [[https://en.wikipedia.org/wiki/Automatic_dependent_surveillance-broadcast|ADS-B]] data could be used to filter out know airplanes from the signal. Rest of the objects should be pick out as suspicious and should be further identified for example using a [[https://en.wikipedia.org/wiki/FDOA|FDOA]] method.
 + 
 +Using VOR beacons to observe meteors has one advantage - these beacons work in a protected air band that is continuously monitored for interference. Therefore, the quality of obtained data is better than in other bands.
 +
 +==== Hardware ====
 +
 +To process and digitise signals, a [[http://www.mlab.cz/WebSVN/filedetails.php?repname=svnkaklik&path=%2Fdokumenty%2Fskolni%2Fdiplomka%2F2014-05-12KakonaDiplThesisCTU-Prague.pdf|new digitizing unit]] should be available. It would be advantageous to change an SDRX01B receiver for a newer version, dedicated to digitise signal in bandwidth approximately 10 MHz, in order to improve the parameters of the receiving chain.
 +
 +===== Data from ADS-B =====
 +
 +To obtain reference data and to filter airplanes, ADS-B data can be used.
 +
 +==== dump1090 ====
 +
 +
 +
 +  sudo apt-get install librtlsdr-dev git
 +  git clone https://github.com/MalcolmRobb/dump1090.git
 +  cd dump1090
 +  make
 +  sudo rmmod dvb_usb_rtl28xxu
 +
 +
 +Now you can run the software e.g. with parameters to create a local web server: 
 +  ./dump1090 --interactive --net
  
en/vor.txt · Last modified: 2021/07/22 06:16 by kaklik