第一章 航海雷達(dá)基本原理

1、MARINE RADAR AND ARPAChapter 1 Basic Principle of RadarMarine Radar and ARPAChapter 1Basic Principle of RadarThe Development & Principle of Marine Radar Radar ConceptThe development of radar techniqueThe use of radar at sea General DescriptionThe principle of range and bearing measurement Display pr

2、esentation of a basic radarMarine Radar and ARPAChapter 1Basic Principle of RadarRadar ConceptGeneral Concept RadarRadio detection and rangingFrom the name: To find and measure the targets that you concern about by way of radio magnetic wave. Scientific definition: Radar is a kind of electronic syst

3、em which can be used to find the targets and to measure or determinate the targets information/data by way of the characteristics of electromagnetic wave.Marine Radar and ARPAChapter 1Basic Principle of RadarThe characteristic of electromagnetic wave: ReflactionFind: ReflectRelayRadiateTargets: All

4、the objects that can be found by radar. Targets information/data: position speed, course, collision avoidance informationconstant speedstraight lineMarine Radar and ARPAChapter 1Basic Principle of Radar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)或固有輻射來探測(cè)目標(biāo)，并測(cè)定目標(biāo)的空間坐、轉(zhuǎn)發(fā)或固有輻射來探測(cè)目標(biāo)，并測(cè)定目標(biāo)的空間坐標(biāo)、速度及避

5、碰參數(shù)的一個(gè)無線電技術(shù)范圍。稱為標(biāo)、速度及避碰參數(shù)的一個(gè)無線電技術(shù)范圍。稱為“雷雷達(dá)達(dá)”?！岸屋椛涠屋椛洹保豪走_(dá)發(fā)射電磁波到目標(biāo)后、目標(biāo)產(chǎn)生：雷達(dá)發(fā)射電磁波到目標(biāo)后、目標(biāo)產(chǎn)生“二二次輻射次輻射”，其中一小部分被雷達(dá)天線接收，稱為目標(biāo)回，其中一小部分被雷達(dá)天線接收，稱為目標(biāo)回波波, 雷達(dá)收到回波便可發(fā)現(xiàn)目標(biāo)。雷達(dá)收到回波便可發(fā)現(xiàn)目標(biāo)?！稗D(zhuǎn)發(fā)轉(zhuǎn)發(fā)”： 來自應(yīng)答器（來自應(yīng)答器（Transponder），），“識(shí)別器識(shí)別器”，后者收到雷達(dá)信號(hào)后發(fā)射經(jīng)過編碼的后者收到雷達(dá)信號(hào)后發(fā)射經(jīng)過編碼的“應(yīng)答波應(yīng)答波”被雷達(dá)被雷達(dá)所接收，從而發(fā)現(xiàn)目標(biāo)。所接收，從而發(fā)現(xiàn)目標(biāo)?！肮逃休椛涔逃休椛洹保簛碜跃哂泄逃休椛?/p>

6、源的目標(biāo)（如飛機(jī)、：來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)上無線電裝置等）雷達(dá)接收目發(fā)動(dòng)機(jī)、核爆炸、目標(biāo)上無線電裝置等）雷達(dá)接收目標(biāo)的固有輻射波而發(fā)現(xiàn)目標(biāo)標(biāo)的固有輻射波而發(fā)現(xiàn)目標(biāo)。Marine Radar and ARPAChapter 1Basic Principle of Radar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、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。顯示、控制和管

7、理。Marine Radar and ARPAChapter 1Basic Principle of Radar1886-1888 Hertz (Germany): realized electromagnetic wave oscillating, transmitting, receiving. 1914 (American): Echo sounderProto-model of radar. 1922 Marconi (Italy): Suggested a practicable radar system. 1930 Blair: Pulse echo measurement (ra

8、nge, direction) systembasic radar. Marine Radar and ARPAChapter 1Basic Principle of RadarRCA Co. (American): Invented airplane-carried radar. (America): “New York” Cruiser equipped with radar. After WWII: As a navigation aids developed rapidly. China: Technique mainly from developed countries. Moder

9、n radar/ARPA: With computer, integrated navigation system (Loran, GPS, ECDIS,AIS), colour TV display Automatic bridge navigation system.Marine Radar and ARPAChapter 1Basic Principle of RadarRadar/ARPA, ECDIS, GPS/DGPS and data auto-pilot combined together will be future major navigation systemMarine

10、 Radar and ARPAChapter 1Basic Principle of Radar雷達(dá)發(fā)展歷程雷達(dá)發(fā)展歷程模擬信號(hào)處理模擬信號(hào)處理數(shù)字信息處理數(shù)字信息處理計(jì)算機(jī)信息處理計(jì)算機(jī)信息處理Marine Radar and ARPAChapter 1Basic Principle of Radar模擬信號(hào)處理模擬信號(hào)處理20世紀(jì)世紀(jì)90年代前，雷達(dá)設(shè)備采用電子管或晶體管，發(fā)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，示在徑向圓周掃描顯示器（平面位置顯示器，Plan

11、 Position Indicator - 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，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，因而被稱為駕駛員像穩(wěn)定清晰，操作簡(jiǎn)單方便，因而被稱為駕駛員“眼眼睛睛”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，無法顯示器，熒光屏的顯示亮度和對(duì)比度受到限制，無法實(shí)現(xiàn)彩色顯示實(shí)現(xiàn)彩色顯示Marine Radar and ARPAChapter 1

12、Basic Principle of RadarMarine Radar and ARPAChapter 1Basic Principle of Radar數(shù)字信號(hào)處理數(shù)字信號(hào)處理雷達(dá)設(shè)備進(jìn)步雷達(dá)設(shè)備進(jìn)步采用數(shù)字處理技術(shù)采用數(shù)字處理技術(shù)采用高亮度光柵掃描顯示（采用高亮度光柵掃描顯示（TV顯示）顯示）實(shí)現(xiàn)實(shí)現(xiàn)ATT和和ARPA功能功能Marine Radar and ARPAChapter 1Basic Principle of Radar計(jì)算機(jī)信息處理計(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)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)大星定

13、位技術(shù)的發(fā)展，雷達(dá)功能更加強(qiáng)大Marine Radar and ARPAChapter 1Basic Principle of RadarThe use of radar at sea Marine radar: Centi-metric wavelength pulse transmitting navigational radarFor our major: The use of radar at sea.Three main applications: fixposition (2) collision anti-(1) .course velocity,bearing),directi

14、on( distance, targetsof parameters theMeasure visibilityoflimitation of free(2)detection range long(1) possible asearly as targetsFind(3) Navigating the ship Marine Radar and ARPAGeneral DescriptionScan directionRange: Echo (at 10 nm) t123.5ss Periphery of CRTOwn shipTargetIsland12 nmTarget90 245 24

15、5EBL901802700Bearing markerChart formRadar pictureFig. Range & bearing measurementSweep line (Length 148.2s Equivalent 12 nm range)Ring (6 Total)HLIslandOwn shipRadar cannot “feel” the back side of a target, therefor target distortion is inevitable.Chapter 1Basic Principle of RadarMarine Radar and A

16、RPAChapter 1Basic Principle of Radar雷達(dá)圖像特點(diǎn)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雷達(dá)圖像不同于海圖，也不同于日常生活中的視覺圖像；雷達(dá)圖像與設(shè)備自身性能、大氣船舶條件、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)；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：大的變形，表現(xiàn)在：P6Marine Radar and ARPAChapter 1Basic Principle of Radar1. Range mea

17、surement t: during which radio wave to and form the target, C: electromagnetic wave travel velocity in free space.R = slant range (antenna aim)Marine Radar and ARPAChapter 1Basic Principle of Radart: very shot;beyond the capability of any conventional time measuring device; Electronic deviceCRT. A v

18、ery small spot of light. The speed of this travel can be accurately controlled at values which allow the spot to transit the screen in as little as a few microseconds.The time taken for the spot to cross the screen is the same as the time taken for a radar pulse to make the two-way journey to a targ

19、et at a chosen range.Marine Radar and ARPAChapter 1Basic Principle of RadarAn echo return from a target is used to produce an increase in the brilliance of the moving spot. When the spot has completed the trace, the brilliance is automatically reduced to zero and the spot flies back to the origin to await the incidence of the next transmission. Marine Radar and ARPAChapter 1Basic Principle of RadarBearing measurement By way of directional antenna (Scanner , Aeria