本文系(xi)統介(jie)(jie)紹了(le)GPS的(de)原理和其三大(da)子系(xi)統，著重介(jie)(jie)紹了(le)GPS系(xi)統在交(jiao)(jiao)通運輸中的(de)應用(yong)，包括在道路工程(cheng)、汽車導航(hang)和交(jiao)(jiao)通管理中的(de)應用(yong)以及其他應用(yong)     一、全(quan)球定位系(xi)統GPS簡介(jie)(jie)     全(quan)球衛星定位系(xi)統GPS是美軍70年代初(chu)在“子午儀衛星導航(hang)定位”技術上發展而起(qi)的(de)具有全(quan)球性(xing)、全(quan)能性(xing)（陸地、海洋、航(hang)空與航(hang)天(tian)）、全(quan)天(tian)候(hou)性(xing)優勢的(de)導航(hang)定位、定時、測速系(xi)統。

      GPS由三大子系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)構成(cheng)：空(kong)間(jian)(jian)(jian)(jian)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)、地(di)(di)面(mian)監控系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)、用戶接收系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)。     空(kong)間(jian)(jian)(jian)(jian)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)     空(kong)間(jian)(jian)(jian)(jian)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)由均(jun)勻分(fen)布(bu)在(zai)6個軌(gui)(gui)(gui)道(dao)(dao)平(ping)(ping)面(mian)上(shang)的(de)(de)(de)24顆(ke)高軌(gui)(gui)(gui)道(dao)(dao)工(gong)(gong)(gong)作(zuo)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)構成(cheng)，各軌(gui)(gui)(gui)道(dao)(dao)平(ping)(ping)面(mian)相對(dui)于赤道(dao)(dao)平(ping)(ping)面(mian)的(de)(de)(de)傾角(jiao)為(wei)55Ο，軌(gui)(gui)(gui)道(dao)(dao)平(ping)(ping)面(mian)間(jian)(jian)(jian)(jian)距60Ο。在(zai)每(mei)(mei)一軌(gui)(gui)(gui)道(dao)(dao)平(ping)(ping)面(mian)內，各衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)升交角(jiao)距差90Ο，任一軌(gui)(gui)(gui)道(dao)(dao)上(shang)的(de)(de)(de)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)比西邊(bian)相鄰軌(gui)(gui)(gui)道(dao)(dao)上(shang)的(de)(de)(de)相應衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)超(chao)前30Ο。事實上(shang)，空(kong)間(jian)(jian)(jian)(jian)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)數(shu)量要超(chao)過24顆(ke)，以(yi)便及(ji)時(shi)(shi)更(geng)換老化(hua)或(huo)損壞(huai)的(de)(de)(de)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)，保(bao)障系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)正常工(gong)(gong)(gong)作(zuo)。該衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)能(neng)夠保(bao)證在(zai)地(di)(di)球(qiu)(qiu)的(de)(de)(de)任一地(di)(di)點(dian)(dian)向使用者提(ti)供4顆(ke)以(yi)上(shang)可(ke)視衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)。     空(kong)間(jian)(jian)(jian)(jian)系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)的(de)(de)(de)每(mei)(mei)顆(ke)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)每(mei)(mei)12小時(shi)(shi)（恒星(xing)(xing)時(shi)(shi)）沿近(jin)圓形軌(gui)(gui)(gui)道(dao)(dao)繞地(di)(di)球(qiu)(qiu)一周(zhou)，由星(xing)(xing)載高精度原子鐘（基頻(pin)F=10.23MHZ）控制無線(xian)電發(fa)(fa)射機(ji)在(zai)“低噪音(yin)窗(chuang)口(kou)”（無線(xian)電窗(chuang)口(kou)中，2至8區(qu)間(jian)(jian)(jian)(jian)的(de)(de)(de)頻(pin)區(qu)天線(xian)噪聲最低的(de)(de)(de)一段(duan)(duan)是空(kong)間(jian)(jian)(jian)(jian)遙測(ce)及(ji)射電干(gan)涉測(ce)量優先選用頻(pin)段(duan)(duan)）附近(jin)發(fa)(fa)射L1、L2兩種載波，向全(quan)球(qiu)(qiu)的(de)(de)(de)用戶接收系(xi)(xi)統(tong)(tong)(tong)(tong)(tong)連(lian)續地(di)(di)播發(fa)(fa)GPS導航(hang)(hang)信號。GPS工(gong)(gong)(gong)作(zuo)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)組(zu)網保(bao)障全(quan)球(qiu)(qiu)任一時(shi)(shi)刻(ke)、任一地(di)(di)點(dian)(dian)都(dou)可(ke)對(dui)4顆(ke)以(yi)上(shang)的(de)(de)(de)衛(wei)(wei)(wei)(wei)(wei)(wei)星(xing)(xing)進行觀測(ce)（最多可(ke)達(da)11顆(ke)），實現連(lian)續、實時(shi)(shi)地(di)(di)導航(hang)(hang)和定位。     

    最具有(you)開創意義的(de)高(gao)新(xin)技(ji)(ji)(ji)術(shu)(shu)之一(yi)，其全球性(xing)、全能性(xing)、全天候性(xing)的(de)導航定位、定時、測速(su)優勢必(bi)然會在(zai)諸多領域中得到越來(lai)越廣(guang)泛的(de)應(ying)用。在(zai)發(fa)達國(guo)家，GPS技(ji)(ji)(ji)術(shu)(shu)已(yi)經(jing)開始應(ying)用于交(jiao)(jiao)通運(yun)輸和(he)道(dao)路工(gong)程(cheng)之中。目前(qian)，GPS技(ji)(ji)(ji)術(shu)(shu)在(zai)我(wo)國(guo)道(dao)路工(gong)程(cheng)和(he)交(jiao)(jiao)通管理中的(de)應(ying)用還(huan)剛(gang)剛(gang)起步(bu)，相信隨著我(wo)國(guo)經(jing)濟的(de)發(fa)展，高(gao)等級公(gong)路的(de)快速(su)修建(jian)和(he)GPS技(ji)(ji)(ji)術(shu)(shu)應(ying)用研究的(de)逐步(bu)深(shen)入(ru)，其在(zai)道(dao)路工(gong)程(cheng)中的(de)應(ying)用也會更(geng)加廣(guang)泛和(he)深(shen)入(ru)，并發(fa)揮更(geng)大的(de)作用。