第一章 航海雷達(dá)基本原理

MARINERADARANDARPAChapter1

BasicPrincipleofRadarChapter1 BasicPrincipleofRadarTheDevelopment&PrincipleofMarineRadarRadarConceptThedevelopmentofradartechniqueTheuseofradaratseaGeneralDescriptionTheprincipleofrangeandbearingmeasurementDisplaypresentationofabasicradarChapter1 BasicPrincipleofRadarRadarConceptGeneralConceptRadar——RadiodetectionandrangingFromthename:Tofindandmeasurethetargetsthatyouconcernaboutbywayofradiomagneticwave.Scientificdefinition:Radarisakindofelectronicsystemwhichcanbeusedtofindthetargetsandtomeasureordeterminatethetargetsinformation/databywayofthecharacteristicsofelectromagneticwave.Chapter1 BasicPrincipleofRadarThecharacteristicofelectromagneticwave:

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ReflactionFind:Reflect\Relay\RadiateTargets:Alltheobjectsthatcanbefoundbyradar.Targetsinformation/data:positionspeed,course,collisionavoidanceinformationconstantspeedstraightlineChapter1 BasicPrincipleofRadar雷達(dá)是一種主動(dòng)遙感設(shè)備，它利用電磁波的二次輻射、轉(zhuǎn)發(fā)或固有輻射來(lái)探測(cè)目標(biāo)，并測(cè)定目標(biāo)的空間坐標(biāo)、速度及避碰參數(shù)的一個(gè)無(wú)線電技術(shù)范圍。稱為“雷達(dá)”。“二次輻射”：雷達(dá)發(fā)射電磁波到目標(biāo)后、目標(biāo)產(chǎn)生“二次輻射”，其中一小部分被雷達(dá)天線接收，稱為目標(biāo)回波,雷達(dá)收到回波便可發(fā)現(xiàn)目標(biāo)?！稗D(zhuǎn)發(fā)”：來(lái)自應(yīng)答器（Transponder），“識(shí)別器”，后者收到雷達(dá)信號(hào)后發(fā)射經(jīng)過(guò)編碼的“應(yīng)答波”被雷達(dá)所接收，從而發(fā)現(xiàn)目標(biāo)?！肮逃休椛洹保簛?lái)自具有固有輻射源的目標(biāo)（如飛機(jī)、發(fā)動(dòng)機(jī)、核爆炸、目標(biāo)上無(wú)線電裝置等）雷達(dá)接收目標(biāo)的固有輻射波而發(fā)現(xiàn)目標(biāo)。Chapter1 BasicPrincipleofRadar現(xiàn)代雷達(dá)與電子計(jì)算機(jī)、圖象處理、數(shù)據(jù)處理、自動(dòng)控制等技術(shù)結(jié)合，又具有自動(dòng)信息處理功能及智能化顯示終端，可自動(dòng)、迅速、準(zhǔn)確地完成測(cè)量、顯示、控制和管理。Chapter1 BasicPrincipleofRadar1886-1888Hertz(Germany):realizedelectromagneticwaveoscillating,transmitting,receiving.1914(American):Echosounder－Proto-modelofradar.1922Marconi(Italy):Suggestedapracticableradarsystem.1930Blair:Pulseechomeasurement(range,direction)system－basicradar.Chapter1 BasicPrincipleofRadarRCACo.(American):Inventedairplane-carriedradar.(America):“NewYork”Cruiserequippedwithradar.AfterWWII:Asanavigationaidsdevelopedrapidly.China:Techniquemainlyfromdevelopedcountries.Modernradar/ARPA:Withcomputer,integratednavigationsystem(Loran,GPS,ECDIS,AIS),colourTVdisplayAutomaticbridgenavigationsystem.Chapter1 BasicPrincipleofRadarRadar/ARPA,ECDIS,GPS/DGPSanddataauto-pilotcombinedtogetherwillbefuturemajornavigationsystemChapter1 BasicPrincipleofRadar雷達(dá)發(fā)展歷程模擬信號(hào)處理數(shù)字信息處理計(jì)算機(jī)信息處理Chapter1 BasicPrincipleofRadar模擬信號(hào)處理20世紀(jì)90年代前，雷達(dá)設(shè)備采用電子管或晶體管，發(fā)射功率較大，回波信號(hào)經(jīng)接收系統(tǒng)實(shí)時(shí)處理，直接顯示在徑向圓周掃描顯示器（平面位置顯示器，PlanPositionIndicator-PPI）優(yōu)點(diǎn)：技術(shù)成熟，具有良好的探測(cè)的分辨目標(biāo)的能力，接收信噪比高，抗干擾能力強(qiáng)，故障率低，目標(biāo)圖像穩(wěn)定清晰，操作簡(jiǎn)單方便，因而被稱為駕駛員“眼睛”缺點(diǎn)：采用實(shí)時(shí)的模擬信號(hào)處理系統(tǒng)和徑向圓周掃描顯示器，熒光屏的顯示亮度和對(duì)比度受到限制，無(wú)法實(shí)現(xiàn)彩色顯示

Chapter1 BasicPrincipleofRadarChapter1 BasicPrincipleofRadar數(shù)字信號(hào)處理雷達(dá)設(shè)備進(jìn)步采用數(shù)字處理技術(shù)采用高亮度光柵掃描顯示（TV顯示）實(shí)現(xiàn)ATT和ARPA功能Chapter1 BasicPrincipleofRadar計(jì)算機(jī)信息處理隨著傳感網(wǎng)技術(shù)、現(xiàn)代通信技術(shù)、信息處理技術(shù)和衛(wèi)星定位技術(shù)的發(fā)展，雷達(dá)功能更加強(qiáng)大Chapter1 BasicPrincipleofRadarTheuseofradaratseaMarineradar:Centi-metricwavelengthpulsetransmittingnavigationalradarForourmajor:Theuseofradaratsea.Threemainapplications:?

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Equivalent12nmrange)Ring(6Total)HLIslandOwnshipRadarcannot“feel”thebacksideofatarget,therefortargetdistortionisinevitable.Chapter1 BasicPrincipleofRadarChapter1 BasicPrincipleofRadar雷達(dá)圖像特點(diǎn)雷達(dá)圖像不同于海圖，也不同于日常生活中的視覺(jué)圖像；雷達(dá)圖像與設(shè)備自身性能、大氣船舶條件、目標(biāo)反射特性以及周圍環(huán)境變化有關(guān)；雷達(dá)探測(cè)到的回波圖像與真實(shí)目標(biāo)相比，可能有較大的變形，表現(xiàn)在：P6Chapter1 BasicPrincipleofRadar1.RangemeasurementΔt:duringwhichradiowavetoandformthetarget,C:electromagneticwavetravelvelocityinfreespace.R=slantrange(antenna–aim)Chapter1 BasicPrincipleofRadarΔt:veryshot;beyondthecapabilityofanyconventionaltimemeasuringdevice;Electronicdevice——CRT.Averysmallspotoflight.Thespeedofthistravelcanbeaccuratelycontrolledatvalueswhichallowthespottotransitthescreeninaslittleasafewmicroseconds.Thetimetakenforthespottocrossthescreenisthesameasthetimetakenforaradarpulsetomakethetwo-wayjourneytoatargetatachosenrange.Chapter1 BasicPrincipleofRadarAnechoreturnfromatargetisusedtoproduceanincreaseinthebrillianceofthemovingspot.Whenthespothascompletedthetrace,thebrillianceisautomaticallyreducedtozeroandthespotfliesbacktotheorigintoawaittheincidenceofthenexttransmission.Chapter1 BasicPrincipleofRadarBearingmeasurementBywayofdirectional

antenna(Scanner,Aerial).Chapter1 BasicPrincipleofRadarChapter1 BasicPrincipleofRadarBearingmeasurementBywayofdirectionalantenna(Scanner,Aerial).Chapter1 BasicPrincipleofRadar1.2.2TheechoprincipleTheechoisneverasloudastheoriginalblast.Thechanceof