gps中英文翻譯--全球定位系統(tǒng)概述

1、<p>　　本科畢業(yè)設(shè)計(jì)（論文）</p><p><b>　　中英文對(duì)照翻譯</b></p><p><b>　　院（系部） </b></p><p>　　專業(yè)名稱 　 </p><p>　　年級(jí)班級(jí)　 </p><p>　　學(xué)生姓

2、名　 </p><p>　　指導(dǎo)老師 </p><p>　　2010年06月11日</p><p>　　Summarizing The Global Positioning System</p><p>　　Abstract: Global Positioning System is bas

3、ed on the background of the United States Department of Defense.It is designed,invested,developed,and operated by the United States Department of Defense ,GPS is a satellite-based positioning and time transfering GPS pos

4、itioning function has a wide range of applications in the modern measurement and a more modern building.GPS-RTK technology is also widely used in modernization building, and now GPS has also been shown to be an important

5、 civilian communit</p><p>　　Keyword:GPS,Locating，RTK，Lay out，Survey</p><p>　　Background </p><p>　　The 50s, the former U.S.S.R has not launched humanities first artificial earth sate

6、llite, the American scientists in along its track research in, had discovered the Doppler shift phenomenon, and has facilitated Doppler satellite navigation posi- tioning system completing using this principle, has obtai

7、ned the enormous success in the military and the civi aspect, was in a navigation localization history leap, our country once has also introduced many Doppler receiver, applied to the island associ</p><p>　　

8、The GPS system control section by is located in the American foundations of the states 5 monitoring stations to be composed, these stand did not ask breaks Carries on the observation to GPS satellite, and will calculate

9、and the forecast information by the infusion stands renews to the satellite information. </p><p>　　The GPS system user is extremely covert, it is one kind of one-way system,the user only receives but does no

10、t need the transmitting message, and therefore user' s quantity also is not limited. Although GPS is the unification starts is, but very quantity also is not limited. Although GPS recei ver and processing software em

11、erge in abundance. At present the receiver which appears in the Chinese market mainly has ROGUE,ASHTECH, TRIMBLE, LEICA, SOKKIA, TOPCON and so on.. Can carry on the observation</p><p>　　The international GPS

12、 geodetic survey served IGS with Earth dynamics from 1992, has established many data storage and the processing center in the whole world, year to year observed a station with hundred, our country has also set up Shangha

13、i Yu Shan, Wuhan, Xian, Taiwan and so on many year to year measuring platforms station, these stations observation data passed on every day through the internet net to US' S data storage center, IGS also nearly real-

14、time synthesizes various data processing ce</p><p>　　The GPS system real-time navigation pointing is very high,US hasimplemented the so-called SA policy in 1992, namely reduces the broadcaststar to undergo t

15、he star posi tion precision, reduces the star clock to change thepositive number the precision, adds on the high frequency vibration to thesatellite datum frequency (to cause false distance measuring accuracy to reducewi

16、th phase ), latter has implemented the A-S policy, soon P yard change is Y yardnamely further limi ts to the precise false dis</p><p>　　GPS localization principal </p><p>　　The GPS receiver may

17、receive and use in the time service accurately to the nanosecond level time information; will use in to forecast the future for several months the satellite to locate the summary position forecast star experience; Uses i

18、n calculates when the localization to need the satelli te coordinates the broadcast star experience, the precision is (each satellite is different several meter to several dozens meters~changes as necessary); As well as

19、GPS system information, like satellite </p><p>　　The GPS receiver may obtain the satellite sign to the code to the receiver distance, because includes the receiver satellite clock the error and the atmospher

20、e propagated error, therefore is called the false distance. The false distance obtains which to the OA code is called the UA code false distance, the precision approximately is about 20 meters, obtains the false distance

21、 to P yard to be called P yard false distance, the precision approximately is about 2 meters. </p><p>　　The GPS receiver to the satellite signal which receives, carries on the decoding or uses other technolo

22、gies, will modulate after the carrier the information removes, will be allowed to restore the carrier. Strict says, the carrier phase should be called the carrier beat frequency phase, it is receives produces the Doppler

23、 shift influence satellite signal carrier phase and receiver this machine vibration difference of the signal phase. Generally experience Yuan time which determined in the receiv</p><p>　　According to the loc

24、ate mode, the GPS localization divides into the simple point localization and the relative localization (difference localization). The simple point localization is according to a receiver observation data determined the

25、receiver position the way, it only can use the false distance view survey, may use in Chef Chuan and so on the summary navigation localization. The relative localization (difference localization) is according to two abov

26、e receivers observation data determined </p><p>　　When localization observation, if the receiver is opposite to the earths surface movement, then is called the dynamic localization, like uses in summary navi

27、gation localization the and so on Chef Chuan precision is 30-100 meter false distance simple point localization, either uses in the city vehicles navigation localization rice level precision false distance difference loc

28、alization(RTK), the real-time difference localization needs the data chain real-time transmits two or many stations observa</p><p>　　When localization observation, if the receiver is opposite to the earths s

29、urface static, then is called the static localization, when carries on controls the net observes, generally selects this method by several receivers also to observe, it can maximum limit display GPS the pointing accuracy

30、,special-purpose Yu Zheizhong the goal receiver is called the earth receiver,is in the receiver a performance best kind. At present, GPS already could achieve the earths crust performance observation the pr</p>&l

31、t;p>　　RTK technologies </p><p>　　The conventional GPS measuring technique, like the static state, the fast static state , the dynamic survey all~eed afterwards to carryon the solution to calculate can obt

32、ain a centimeter level the precision, but RTK is can real-time obtain the centimeter level pointing accuracy in the open country the measuring technique, it has used the carrier phase dynamic real-time difference (Real-t

33、imekinematics) the method, is the GPS application significant milestone, its appearance for the project layou</p><p>　　The high accuracy GPS survey must use the carrier phase observation value,the RTK locali

34、zation technology, it can real-time provide in assigns in the coordinate system the three dimensional localization result, and achieves the centimeter level precision. Under the RTK work pattern, the datum stands through

35、 the data chain transmi ts together its observation value and the survey station coordinates information for the mobile station. Mobile stands not only receives the data through the data link </p><p>　　The R

36、TK technology key lies in the data processing technology and the data transmission technology, when the RTK localization requests the datum station receiver real-time the observation data (false distance observation valu

37、e, phase observation value) and the know data transmission for the mobile station receive, the data quantity quite big, generally all requests 9,600 bauds rate, this in on radio is not difficult to realize.</p>&l

38、t;p>　　The application of RTK</p><p>　　Each kind of control survey</p><p>　　The traditional geodetic survey, the project control survey uses the triangular net, the line-network method execute

39、s measured, not only requires a lot of work time-consuming, request Indivisibility, moreover the precision distribution non-uniformity, also at the field operation did not know how the precision, does use conventional th

40、e GPS static state survey, the fast static state, the false dynamic method, survey in the process at field operation not to be able real-time to know the pointing a</p><p>　　Terrain mapping</p><p&

41、gt;　　In the past measured when topographic diagram generally first must in measure area establishment chart root control point, then on chart root control point top carriage entire station meter or altazimuth coordinatio

42、n small flat panel mapping, now develops the field operation with the entire station meter and the electronic hand coordination thing code, uses big scale mapping software to carryon the mapping, even develops recent fie

43、ld operation electron dull mapping and so on, all requests in the</p><p><b>　　Layout</b></p><p>　　Layout surveys an application branch, it request through the certain method to use t

44、he certain instrument the spot position which artificial designs in really for to demarcate, in the past used the convention layout the method very many, like the altazimuth junction met layout, when the ent ire 50 stati

45、on meter and so on, generally layout a design position, often needed the back and forth bile target, moreover took 2-3 person to operate, simultaneously also requested the indivisibility situation</p><p>　　5

46、. The application of GPS</p><p>　　GPS offers for military and makes a reservation and sets up accurately at first, it is still controlled by the American military so far. Military GPS products is it confirm

47、and follow in field advancing soldering and coordinating of equipment in to used for mainly, the gunship for the sea navigates, offers the position and navigation information for military aircraft.</p><p>　　

48、(1) The GPS system use is extensively</p><p>　　At present, application, GPS of system very extensive already, we can use GPS signal can carryon sea, empty and navigation of land, the guidance of the guided m

49、issile, earth measurement and accurate localization of project measurement., transmission of time and measurement of the speed,etc.For survey and draw field,GPS satellite fix technology is it set up nationwide earth meas

50、urement of high accuracy control network to use for already, determine global dynamic parameter of earth;Used for settin</p><p>　　(2) Appearance of the resource environment of pluralistic space</p>&l

51、t;p>　　At present, GPS, GLONASS, INMARSAT waits for the system to all possess and navigate to orient the function, formed the pluralistic room resource environment. This pluralistic space environment ,has impelled and

52、fumed a piece of common tactics internationally and folly, namely on one hand fully utilize the existing system, on the other hand prepare to establish folk GNSS system actively ,by the tome around the2010,GNSS folk syst

53、em build our purely, the woke world form the tendency that GPS/GLONAS</p><p>　　(3) Develop gaps industry</p><p>　　GPS Will form industrialization like the automobile, wireless communication at p

54、resent in the future, US>A strengthen wide area systematic WAAS (namely wide area is it revise date chain transfer to already, it make geostationary satellite it have C? A yards of function too, form wide area the GPS

55、 strengthen system of) plan international standard of developing into of. Some units produce car-mounted GPS system too at present in our country.For GPS industry of developing our country, already China</p><p

56、><b>　　全球定位系統(tǒng)概述</b></p><p>　　摘要：全球定位系統(tǒng)是以美國國防為背景，由美國國防部設(shè)計(jì)、投資、開發(fā)、和運(yùn)行的。GPS是以衛(wèi)星定位和時(shí)間傳輸為基礎(chǔ)，GPS定位功能在現(xiàn)代測(cè)量和現(xiàn)代建設(shè)中有較為廣泛的應(yīng)用，GPS-RTK技術(shù)也在現(xiàn)代化建設(shè)中有著廣泛的應(yīng)用，現(xiàn)在GPS 也已經(jīng)顯示出對(duì)平民社區(qū)的一種重要的利益，且其應(yīng)用范圍越來越廣泛。</p><p

57、>　　關(guān)鍵詞：GPS、定位、RTK、放樣、測(cè)量</p><p><b>　　1、背景</b></p><p>　　五十年代末，原蘇聯(lián)發(fā)射了人類的第一顆人造地球衛(wèi)星，美國科學(xué)家在對(duì)其的跟蹤研究中，發(fā)現(xiàn)了多普勒頻移現(xiàn)象，并利用該原理促成了多普勒衛(wèi)星定位導(dǎo)航系統(tǒng)的建成，在軍事和民用方面取得了巨大的成功，是導(dǎo)航定位史上的一次飛躍，我國也曾引進(jìn)了多臺(tái)多普勒接收機(jī)，應(yīng)用與海

58、島聯(lián)測(cè)、地球勘探等領(lǐng)域。但由于多普勒衛(wèi)星軌道高度低、信號(hào)載波頻率低，軌道精度難以提高，使得定位精度較低，以滿足大量測(cè)量或工程測(cè)量的要求，更不能用于天文地球動(dòng)力學(xué)研究。為了提高衛(wèi)星定位的精度，美國從1973 年開始籌建全球定位系統(tǒng)GPS創(chuàng)(Global Positioning System)。在進(jìn)行了方案論證、系統(tǒng)試驗(yàn)階段后，于1989 年開始發(fā)射正式工作衛(wèi)星，并于1994 年全部建成，投入使用。GPS系統(tǒng)的空間部分由21顆衛(wèi)星組成，均分

59、布在 6個(gè)軌道上，地面高度為20000余公里，軌道傾角為55度，扁心率約為0，周期約為 12小時(shí)，衛(wèi)星向地面發(fā)射兩個(gè)波段的載波信號(hào)，載波信號(hào)頻率分別為1575.442兆赫茲(L1波段)和1227.6兆赫茲(L2波段)，衛(wèi)星上安裝了精度很高的原子鐘，以確保頻率的穩(wěn)定性，在載波上調(diào)制有表示衛(wèi)星位置的廣播星歷，用于</p><p>　　GPS 系統(tǒng)的控制部分有設(shè)在美國本上的5個(gè)監(jiān)控站組成，這些站間不斷地GPS衛(wèi)星進(jìn)行觀

60、測(cè)，并將計(jì)算和預(yù)報(bào)的信息由注入站對(duì)衛(wèi)星信息更新。</p><p>　　GPS系統(tǒng)的用戶是非常隱蔽的，它是一種單程系統(tǒng)，用戶只接收而不必發(fā)射信號(hào)，因此用戶的數(shù)量也是不受限制的。雖然GPS系統(tǒng)一開始是為軍事目的而建立的，但很快在民用方面得到了極大的發(fā)展，各類GPS 接收機(jī)和處理軟件紛紛涌現(xiàn)出來。能對(duì)兩個(gè)頻率進(jìn)行觀測(cè)的接收機(jī)稱為雙頻接收機(jī)，只能對(duì)一個(gè)頻率進(jìn)行觀測(cè)的接收機(jī)稱為單頻接收機(jī)，他們?cè)诰群蛢r(jià)格上均有較大區(qū)別。對(duì)

61、于測(cè)繪界的用戶而言，GPS己在測(cè)繪領(lǐng)域引起了革命性的變化，目前，范圍上數(shù)公里至幾千公里的控制網(wǎng)或變形監(jiān)測(cè)網(wǎng)，精度上從幾百至毫米級(jí)的定位，一般都將GPS作為首選手段，隨著RTK 技術(shù)的日趨成熟，GPS一開始向分米乃至厘米級(jí)的放樣、高精度動(dòng)態(tài)定位等領(lǐng)域滲透。</p><p>　　國際GPS大地測(cè)量和地球動(dòng)力學(xué)服務(wù)IGS自1992 年起，己在全球建立了多個(gè)數(shù)據(jù)存儲(chǔ)及處理中心，和百余個(gè)常年觀測(cè)的臺(tái)站，我國也設(shè)立了上海余山

62、、武漢、西安、拉薩、臺(tái)灣等多個(gè)常年觀測(cè)臺(tái)站，這些臺(tái)站的觀測(cè)數(shù)據(jù)每天通過INTERNET網(wǎng)傳向美國的數(shù)據(jù)存儲(chǔ)中心，IGS還幾乎實(shí)時(shí)地綜合各數(shù)據(jù)處理中心的結(jié)果，并參與國際地球自轉(zhuǎn)服務(wù)IERS的全球坐標(biāo)參考系維護(hù)及地球自轉(zhuǎn)參數(shù)的發(fā)布。使用者也可免費(fèi)從INTERNET網(wǎng)上取得觀測(cè)數(shù)據(jù)及梗米數(shù)據(jù)等產(chǎn)品。</p><p>　　GPS系統(tǒng)的實(shí)時(shí)導(dǎo)航定位精度很高，美國在1992年起實(shí)行了所謂的SA政策，即降低廣播星歷中衛(wèi)星位置的

63、精度，降低衛(wèi)星鐘改正數(shù)的精度，對(duì)衛(wèi)星基準(zhǔn)頻率加上高頻的抖動(dòng)(使偽距和相位的量測(cè)精度降低)，后又實(shí)行了A-S政策，即將P碼改變?yōu)閅碼，即對(duì)精密偽距測(cè)量進(jìn)一步限制，而美國軍方和特許用戶不受這些政策的影響，但美國為了獲得更大的商業(yè)利益，這些政策終將被取消。</p><p><b>　　2、GPS定位原理</b></p><p>　　GPS 接收機(jī)可接收到可用于授時(shí)的準(zhǔn)確至納

64、秒級(jí)的時(shí)間信息，用于預(yù)報(bào)未來幾個(gè)月內(nèi)衛(wèi)星所處概略位置的預(yù)報(bào)星歷:用于計(jì)算定位時(shí)所需衛(wèi)星坐標(biāo)的廣播星歷，精度為幾米至幾十米(各個(gè)衛(wèi)星不同，隨時(shí)變化);以及GPS系統(tǒng)信息，如衛(wèi)星狀況等。</p><p>　　GPS接收機(jī)對(duì)碼的量測(cè)就可得到衛(wèi)星到接收機(jī)的距離，由于含有接收機(jī)衛(wèi)星鐘的誤差及大氣傳播誤差，故稱為偽距。對(duì)OA碼測(cè)得的偽距稱為UA碼偽距，精度約為20米左右，對(duì)P碼測(cè)得的偽距稱為P碼偽距，精度約為2 米左右。&l

65、t;/p><p>　　GPS接收機(jī)對(duì)收到的衛(wèi)星信號(hào)，進(jìn)行解碼或采用其它技術(shù)，將調(diào)制在載波上的信息去掉后，就可以恢復(fù)載波。嚴(yán)格再言，載波相位應(yīng)被稱為載波拍頻相位，它是收到的受多普勒頻移影響的衛(wèi)星信號(hào)載波相位與接收基本機(jī)振蕩產(chǎn)生信號(hào)相位之差。一般在接收機(jī)鐘確定的歷元時(shí)刻量測(cè)，保持對(duì)衛(wèi)星信號(hào)的跟蹤，就可記錄下相位的變化值，但開始觀測(cè)時(shí)的接收機(jī)和衛(wèi)星振蕩器的相位初值是不知道的，起始?xì)v元的相位整數(shù)也是不知道的，即整周模糊度，只

66、能在數(shù)據(jù)處理中作為參數(shù)解算。相位觀測(cè)值得精度高至毫米，但前提是解出整周模糊度，因此只有在相對(duì)定位、并有一段連續(xù)觀測(cè)值時(shí)才能使用相位觀測(cè)值，而要達(dá)到優(yōu)于米級(jí)的定位精度也只能采用相位觀測(cè)值。</p><p>　　按定位方式， GPS定位分為單點(diǎn)定位和相對(duì)定位(差分定位)。單點(diǎn)定位就是根據(jù)一臺(tái)接收機(jī)的觀測(cè)數(shù)據(jù)來確定接收機(jī)位置的方式，它只能采用偽距觀測(cè)量，可用于車船等的概略導(dǎo)航定位。相對(duì)定位(差分定位)是根據(jù)兩臺(tái)以上接收

67、機(jī)的觀測(cè)數(shù)據(jù)來確定觀測(cè)點(diǎn)之間的相對(duì)位置的方法，它既可采用偽距觀測(cè)量也可采用相位觀測(cè)量，大地測(cè)量或工程測(cè)量均應(yīng)采用相位觀測(cè)值進(jìn)行相對(duì)定位。在GPS觀測(cè)量中包含了衛(wèi)星和接收機(jī)的鐘差、大氣傳播延遲、多路經(jīng)效應(yīng)等誤差，在定位計(jì)算時(shí)還要受到衛(wèi)星廣播星歷誤差的影響，在進(jìn)行相對(duì)定位時(shí)大部分公共誤差被抵消或削弱，因此定位精度降大大提高，雙頻接收機(jī)可以根據(jù)兩個(gè)頻率的觀測(cè)量抵消大氣中電離層誤差的主要部分，在精度要求高，接收機(jī)間距離較遠(yuǎn)時(shí)(大氣有明顯差別)，

68、應(yīng)選用雙頻接收機(jī)。</p><p>　　在定位觀測(cè)時(shí)，若接收機(jī)相對(duì)于地球表面運(yùn)動(dòng)，則稱為動(dòng)態(tài)定位，如用于車船等粗略導(dǎo)航定位的精度為30-100 米的偽距單點(diǎn)定位，或用于城市車輛導(dǎo)航定位的米級(jí)精度的偽距差分定位，或用于測(cè)量放樣等的厘米級(jí)的相位差分定位(RTK)，實(shí)時(shí)差分定位需要數(shù)據(jù)連降兩個(gè)或多個(gè)站的觀測(cè)數(shù)據(jù)實(shí)時(shí)傳輸?shù)揭黄鹩?jì)算。</p><p>　　在定位觀測(cè)時(shí)，若接收機(jī)相對(duì)于地球表面靜止，則

69、稱為靜態(tài)定位，在進(jìn)行控制網(wǎng)觀測(cè)時(shí)，一般均采用這種方式由幾臺(tái)接收機(jī)同時(shí)觀測(cè)，它能最大限度地發(fā)揮GPS的定位精度，專用于這種目的的接收機(jī)被稱為大地型接收機(jī)，是接收機(jī)中性能最好的一類。目前，GPS己經(jīng)能夠達(dá)到地殼形變觀測(cè)的精度要求， IGS常年觀測(cè)臺(tái)站己經(jīng)能構(gòu)成毫米級(jí)的全球坐標(biāo)框架。</p><p><b>　　3、RTK 技術(shù)</b></p><p>　　常規(guī)的GPS測(cè)量

70、方法，如靜態(tài)、快速靜態(tài)、動(dòng)態(tài)測(cè)量都需要事后進(jìn)行解算才能獲得厘米級(jí)的精度，而RTK 是能夠在野外實(shí)時(shí)得到厘米級(jí)定位精度的測(cè)量方法，它采用了載波相位動(dòng)態(tài)實(shí)時(shí)差分(Real-time Kinematic)方法，是GPS 應(yīng)用的最大里程碑，它的出現(xiàn)為工程放樣、地形測(cè)圖，各種控制測(cè)量帶來了新曙光，極大地提高了外業(yè)作業(yè)效率。</p><p>　　高精度的GPS測(cè)量必須采用載波相位觀測(cè)值，RTK 定位技術(shù)就是基于載波相位觀測(cè)值

71、的實(shí)時(shí)動(dòng)態(tài)定位技術(shù)，它能夠?qū)崟r(shí)地提供測(cè)站點(diǎn)在指定坐標(biāo)系中的三維定位結(jié)果，并達(dá)到厘米級(jí)精度。在RTK 作業(yè)模式下，基準(zhǔn)站通過數(shù)據(jù)鏈將其觀測(cè)值和測(cè)站坐標(biāo)信息一起傳送給流動(dòng)站。流動(dòng)站不僅通過數(shù)據(jù)鏈接收來自基準(zhǔn)站的數(shù)據(jù)，還要采集GPS 觀測(cè)數(shù)據(jù)，并在系統(tǒng)內(nèi)組成差分觀測(cè)值進(jìn)行實(shí)時(shí)處理，同時(shí)給出厘米級(jí)定位結(jié)果，歷時(shí)不到一秒鐘。流動(dòng)站可處于靜止?fàn)顟B(tài)，也可處于運(yùn)動(dòng)狀態(tài);可在固定點(diǎn)上進(jìn)行初始化后再進(jìn)入動(dòng)態(tài)作業(yè)，也可在動(dòng)態(tài)條件下直接開機(jī)，并在動(dòng)態(tài)環(huán)境下完成

72、周模糊度的搜索求解。在整周未知數(shù)解固定后，即可進(jìn)行每個(gè)歷元的實(shí)時(shí)處理， 只要能保持四顆以上衛(wèi)星相位觀測(cè)值的跟蹤和必要的幾何圖形，則流動(dòng)站可隨時(shí)給出厘米級(jí)定位結(jié)果。</p><p>　　RTK 技術(shù)的關(guān)鍵在于數(shù)據(jù)處理技術(shù)和數(shù)據(jù)傳輸技術(shù)，RTK 定位時(shí)要求基準(zhǔn)站接收機(jī)實(shí)時(shí)地把觀測(cè)數(shù)據(jù)(偽距觀測(cè)值，相位觀測(cè)值及己知數(shù)據(jù)傳輸給流動(dòng)站接收機(jī)，數(shù)據(jù)量比較大，一般都要求9600 的波特率，這在無線電上不難實(shí)現(xiàn)。</p&g

73、t;<p>　　4、RTK 技術(shù)的應(yīng)用</p><p><b>　　(1)各種控制測(cè)量</b></p><p>　　傳統(tǒng)的大地測(cè)量、工程控制測(cè)量采用三角網(wǎng)、導(dǎo)線網(wǎng)來施測(cè)，不僅費(fèi)工費(fèi)時(shí)，要求點(diǎn)與點(diǎn)之間通視，而且精度分布不均勻，且在外業(yè)不知精度如何，采用常規(guī)的GPS靜態(tài)測(cè)量、快速靜態(tài)、偽靜態(tài)方法，在外業(yè)測(cè)設(shè)過程中，不能實(shí)時(shí)知道定位精度，如果測(cè)設(shè)完成后，回到內(nèi)

74、業(yè)處理，發(fā)現(xiàn)精度不合要求，還必須返測(cè)，而采用RTK 來進(jìn)行控制測(cè)量，能夠?qū)崟r(shí)知道定位精度，如果點(diǎn)位精度要求滿足了，用戶就可以停止觀測(cè)了，而且知道觀測(cè)質(zhì)量如何，這樣可以大大提高作業(yè)效率。如果把RTK用于公路控制測(cè)量、電子線路控制測(cè)量、水利工程控制測(cè)量、大地測(cè)量、則不僅可以大大減少人力強(qiáng)度、節(jié)省費(fèi)用，而且大大提高工作效率，測(cè)一個(gè)控制點(diǎn)在幾分鐘甚至于幾秒鐘內(nèi)就可完成。</p><p><b>　　(2)地形測(cè)

75、量</b></p><p>　　過去測(cè)地形圖時(shí)，一般首先要在測(cè)區(qū)建立圖根控制點(diǎn)，然后在圖根控制點(diǎn)上架上全站儀或經(jīng)緯儀，配合小平板測(cè)圖，現(xiàn)在發(fā)展到外業(yè)用全站儀和電子手薄配合地物編碼，利用大比例尺測(cè)圖軟件來進(jìn)行測(cè)圖，甚至于發(fā)展到最近的外業(yè)電子平板測(cè)圖等，都要求在測(cè)站長(zhǎng)測(cè)四周的地形、地貌等碎部點(diǎn)，這些碎部點(diǎn)都與測(cè)站通視，而且一般要求至少2-3人操作，需要在拼圖時(shí)一旦精度不合要求還得到外業(yè)去返測(cè)，現(xiàn)在采用RT

76、K 時(shí)，僅需一人背著儀器在要測(cè)的地形地貌點(diǎn)呆上一二秒鐘，并同時(shí)輸入特征編碼，同過手薄可以實(shí)時(shí)知道點(diǎn)位精度，把一個(gè)區(qū)域測(cè)完后回到室內(nèi)，由專業(yè)的軟件接口就可以輸出所要求的地形圖，這樣用RTK僅需一人操作，不要求點(diǎn)與點(diǎn)間通視，大大提高了工作效率，采用RTK 配合電子手薄可以測(cè)設(shè)各種地形圖，如普通地測(cè)圖、鐵路線路帶狀地形圖的測(cè)設(shè)，公路管線地形圖的測(cè)設(shè)，配合測(cè)深儀可以用于測(cè)水庫地形圖，航海海洋測(cè)圖等等。</p><p>&

77、lt;b>　　(3)放樣</b></p><p>　　放樣是測(cè)量的一個(gè)應(yīng)用分支，它要求通過一定方法，采用一定儀器把人為設(shè)計(jì)好的地位在實(shí)地給標(biāo)定出來，過去采用常規(guī)的測(cè)量放樣方法很多，如：經(jīng)緯儀交會(huì)放樣，全站儀的邊角放樣等等，一般要放樣出一個(gè)設(shè)計(jì)點(diǎn)位時(shí)，往往需要來回移動(dòng)目標(biāo)，而且要2-3人操作，同時(shí)在放樣過程中還要求點(diǎn)與點(diǎn)間通視情況良好，在生產(chǎn)應(yīng)用上效率不是很高，有時(shí)放樣中遇到困難的情況很復(fù)雜，要借

78、助于很多方法才能放樣，如果采用RTK技術(shù)放樣時(shí)，僅需把設(shè)計(jì)好的點(diǎn)位坐標(biāo)輸入到電子手薄中，背著GPS 接收機(jī)，它會(huì)提醒你走到要放樣點(diǎn)的位置，即迅速又方便，由于GPS是通過坐標(biāo)來直接放樣的，而且精度很高也很均勻，因而在外業(yè)放樣中效率會(huì)大大提高，且只需一人操作。</p><p><b>　　5、GPS的應(yīng)用</b></p><p>　　GPS 最初就是為軍方提供精確定位而建

79、立的，至今它仍然由美國軍方控制。軍用GPS產(chǎn)品主要用來確定并跟蹤在野外行進(jìn)中的士兵和裝備的坐標(biāo)，給海中的軍艦導(dǎo)航，為軍用飛機(jī)提供位置和導(dǎo)航信息等。</p><p>　　(1) GPS系統(tǒng)用途廣泛</p><p>　　目前，GPS系統(tǒng)的應(yīng)用己經(jīng)十分廣泛，我們可以應(yīng)用GPS信號(hào)進(jìn)行海、空和陸地的導(dǎo)航，導(dǎo)彈的制導(dǎo)，大地測(cè)量和工程測(cè)量的精密定位，時(shí)間的傳遞和速度的測(cè)量等。對(duì)于測(cè)繪領(lǐng)域， GPS衛(wèi)星

80、定位技術(shù)己經(jīng)用于建立高精度的全國性的大地測(cè)量控制網(wǎng)，測(cè)定全球性的地球動(dòng)態(tài)參數(shù);用于建立陸地海洋大地測(cè)量基準(zhǔn)，進(jìn)行高精度的海島陸地聯(lián)測(cè)以及海洋測(cè)繪;用于監(jiān)測(cè)地球板塊運(yùn)動(dòng)狀態(tài)和地殼形變:用于工程測(cè)量，成為建立城市與工程控制網(wǎng)的主要手段。用于測(cè)定航空航天攝影瞬間的相機(jī)位置，實(shí)現(xiàn)僅有少量地面控制或無地面控制的航測(cè)快速成圖，導(dǎo)致地理信息系統(tǒng)、全球環(huán)境遙感監(jiān)測(cè)的技術(shù)革命。許多商業(yè)和政府機(jī)構(gòu)也使用GPS 設(shè)備來跟蹤他們的車輛位置，這一般需要借助無線通

81、信技術(shù)。一些GPS接收器集成了收音機(jī)、無線電話和移動(dòng)數(shù)據(jù)終端來適應(yīng)車隊(duì)管理的需要。</p><p>　　(2)多元化空間資源環(huán)境的出現(xiàn)</p><p>　　目前，GPS，GLONASS，INMARSAT等系統(tǒng)都具備了導(dǎo)航定位功能，形成了多元化的空間資源環(huán)境。這一多元化的空間資源環(huán)境，促使國際民間形成了一個(gè)共同的策略，即一方面對(duì)現(xiàn)有系統(tǒng)從分利用，一方面積極籌建民間GNSS系統(tǒng)，待到2010年

82、前后，GNSS純民間系統(tǒng)建成，全球?qū)⑿纬蒅PS/GLONASS/GNSS三足鼎立之勢(shì)，才能從根本上擺脫對(duì)單一系統(tǒng)的依賴，形成國際共有、國際共享的安全資源環(huán)境。世界才可進(jìn)入將衛(wèi)星導(dǎo)航作為單一導(dǎo)航手段的最高應(yīng)用境界。國際民間的這一策略，反過來有影響和迫使美國對(duì)其GPS 使用政策做出更開放的調(diào)整?？傊?，由于多元化空間資源環(huán)境的確立，給GPS的發(fā)展應(yīng)用創(chuàng)造了一個(gè)前所未有的良好的國際環(huán)境。</p><p>　　(3)發(fā)展G