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Parizvino, hapana akawanda ekutaurirana maitiro ayo, kune rumwe rutivi, anoda kuziva uye anonakidza, kune rumwe rutivi, tsananguro yavo haitore mapeji mazana mashanu muPDF fomati. Imwe yechiratidzo chakadaro chiri nyore kudhidha iVHF Omni-directional Radio Beacon (VOR) chiratidzo chinoshandiswa mukufambisa kwemhepo.
VOR Beacon (c) wikimedia.org
Chekutanga, mubvunzo wevaverengi: nzira yekugadzira chiratidzo kuitira kuti gwara rigone kutariswa uchishandisa omnidirectional kugamuchira antenna? Mhinduro iri pasi pekucheka.
General information
maitiro (VOR) yakashandiswa pakufamba kwemhepo kubva kuma50s ezana ramakore rapfuura, uye ine ipfupi-renji redhiyo mabhekoni (100-200 km), inoshanda muVHF frequency renji 108-117 MHz. Iye zvino, munguva yegigahertz, zita rakakwirira kwazvo frequency maererano nemafambiro akadaro rinonzwika kusetsa uye pacharo rinotaura nezve. age chiyero ichi, asi nenzira, mabhekoni achiri kushanda , inoshanda mukati mepakati wave wave 400-900 kHz.
Kuisa antenna inotungamira mundege haina kurongeka, saka dambudziko rakamuka rekuti ungaisa sei ruzivo nezve gwara kune bhekoni muchiratidzo pachayo. Nheyo yekushanda "paminwe" inogona kutsanangurwa sezvinotevera. Ngatimbofungidzirai isu tine bhekoniwo zvaro rinotumira kunze danda rakatetepa rechiedza chegirini, mwenje waro unotenderera kamwechete paminiti. Sezviri pachena, kamwe chete paminiti tichaona kupenya kwechiedza, asi kumwe kupenya kwakadaro hakutakuri mashoko akawanda. Ngatiwedzerei yechipiri kubhekoni non-directional rambi dzvuku rinopenya panguva apo mwenje weimba yemwenje "papfuura" nzira kuchamhembe. Nokuti iyo nguva yekupenya uye marongero ebhekoni anozivikanwa; nekuverenga kunonoka pakati pekupenya dzvuku negirinhi, unogona kuona azimuth kuchamhembe. Zviri nyore. Inoramba ichiita chinhu chimwe chete, asi kushandisa redhiyo. Izvi zvakagadziriswa nekushandura zvikamu. Zviratidzo zviviri zvinoshandiswa kutapurirana: chikamu chekutanga chinoramba chiripo (reference), chikamu chechipiri (chinoshanduka) chinoshanduka nenzira yakaoma zvichienderana nekutungamirirwa kwemwaranzi - imwe neimwe kona ine chikamu chayo chekuchinja. Nokudaro, mumwe nomumwe anogamuchira achagamuchira chiratidzo ne "chake" chikamu chekuchinja, zvakaenzana neazimuth kune bhekoni. Iyo "spatial modulation" tekinoroji inoitwa pachishandiswa antenna yakakosha (Alford Loop, ona KDPV) uye yakakosha, pane inonyengera modulation. Icho chiri chaicho musoro wechinyorwa ichi.
Ngatimbofungidzirai isu tine yakajairwa legacy beacon, inoshanda kubva kuma50s, uye ichitumira masaini mune yakajairwa AM modulation muMorse kodhi. Zvichida, pane imwe nguva, mufambisi wengarava ainyatsoteerera zviratidzo izvi mumahedhifoni uye akatara nzira nemutongi uye kambasi pamepu. Tinoda kuwedzera mabasa matsva kuchiratidzo, asi nenzira yakadai kuti tisa "kuputsa" kuenderana nevekare. Musoro wacho unozivikanwa, hapana chinhu chitsva ... Yakaitwa sezvinotevera - yakaderera-frequency 30 Hz toni yakawedzerwa kuchiratidzo che AM, ichiita basa rechiratidzo-chikamu chechiratidzo, uye chikamu chepamusoro-frequency, chakavharidzirwa nehuwandu. modulation pane frequency ye9.96 KHz, kuendesa chiratidzo chechikamu chinoshanduka. Nekusarudza zviratidzo zviviri uye kuenzanisa zvikamu, tinowana kona yatinoda kubva pa0 kusvika ku360 degrees, inova azimuth inodiwa. Panguva imwecheteyo, zvese izvi hazvizokanganisa kuteerera bhekoni "nenzira yakajairwa" uye inoramba ichienderana nevakuru vanogamuchira AM.
Ngatibve padzidziso todzidzira. Ngatitangei SDR inogamuchira, sarudza AM modulation uye 12 KHz bandwidth. VOR beacon frequency inogona kuwanikwa zviri nyore online. Pa spectrum, chiratidzo chinotaridzika seizvi:
Muchiitiko ichi, chiratidzo chebhekoni chinoparidzirwa pahuwandu hwe113.950 MHz. Pakati unogona kuona zviri nyore kuzivikanwa amplitude modulation mutsetse uye Morse code zviratidzo (.- - ... zvinoreva AMS, Amsterdam, Schiphol Airport). Pachinhambwe che9.6 KHz kubva kune mutakuri, nhongonya mbiri dzinoonekwa, dzichitumira chiratidzo chechipiri.
Ngatirekode chiratidzo muWAV (kwete MP3 - kurasikirwa kwekumanikidza "kuchauraya" chimiro chese chechiratidzo) uye tivhure muGNU Radio.
Decoding
vanotsika 1. Ngativhure faira nechiratidzo chakanyorwa uye tishandise yakaderera-pass sefa kwairi kuti uwane yekutanga referensi chiratidzo. Iyo GNU Radio girafu inoratidzwa mumufananidzo.
Mhedzisiro: yakaderera frequency chiratidzo pa30 Hz.
vanotsika 2: decode the variable phase sign. Sezvambotaurwa pamusoro, iri pafrequency ye9.96 KHz, isu tinofanirwa kuifambisa kune zero frequency toidyisa kune FM demodulator.
GNU Radio girafu:
Ndizvozvo, dambudziko rakagadziriswa. Isu tinoona masaini maviri, mutsauko wechikamu unoratidza kona kubva kune anogamuchira kuenda kuVOR beacon:
Chiratidzo chine ruzha, uye kuwedzera kusefa kunogona kudikanwa kuti uverenge mutsauko wechikamu, asi ndinovimba musimboti wakajeka. Kune avo vakakanganwa kuti mutsauko wechikamu unotarwa sei, mufananidzo kubva :
Neraki, haufanirwe kuita zvese izvi nemaoko: zviripo muPython, decoding VOR masaini kubva kuWAV mafaera. Kutaura zvazviri, kudzidza kwake kwakandikurudzira kuti ndidzidze nyaya iyi.
Avo vanofarira vanogona kumhanyisa chirongwa mukoni uye votora kona yapera mumadhigirii kubva kune yakatorekodhwa faira:
Vafambi vendege vanogona kutogadzira yavo inotakurika inogamuchira vachishandisa RTL-SDR uye Raspberry Pi. Nenzira, pane "chaiyo" ndege chiratidzo ichi chinotaridzika seizvi:
Mufananidzo Β©
mhedziso
Zviratidzo zvakadaro "kubva muzana remakore rapfuura" zvechokwadi zvinonakidza pakuongorora. Chekutanga, iwo ari nyore, DRM yemazuva ano kana, kunyanya, GSM, hazvichagoneke kutsanangura "paminwe yako". Ivo vakavhurika kugamuchirwa uye havana makiyi kana cryptography. Chechipiri, pamwe mune ramangwana vanozove nhoroondo uye votsiviwa nesatellite navigation uye mamwe emazuva ano madhijitari masisitimu. Chechitatu, kudzidza zviyero zvakadaro zvinokutendera kuti udzidze inonakidza tekinoroji uye nhoroondo nhoroondo yekuti matambudziko akagadziriswa sei uchishandisa mamwe masekete uye element element yezana ramakore rapfuura. Saka varidzi vanogamuchira vanogona kurairwa kuti vagamuchire masaini akadaro ivo vachiri kushanda.
Semazuva ese, kuyedza kunofadza munhu wese.
Source: www.habr.com