A Satellite Positioning Systemthat Serves You Day and Night2006114

GPS GPS33,000 (HK$2,200)45,000 (HK$3,000)525 (HK$35) Secom's services.200510,000 (: The Japan Times Nov. 5, 2004)

GPS120GPS (: USA TODAY May 9, 2004)

GPS+GPS++

GPSUS$100- 4007-30

GPSGPSL1 C/A 16GPSWAAS 15 USBGPS8

:http://www.globalsat.com.tw/

GPS

(GNSS)(Global Navigation Satellite System)-GPSGLONASS GALILEO

Global Positioning System (GPS)19701989 1995 24 6 22005 29GPS (Modernized GPS)

Russian Global Navigation Sputnik System (GLONASS)2431982199380GLONASS200010200412 2005 142007 18 (: http://www.spaceandtech.com/spacedata/constellations/glonass_consum.shtml)

(GALILEO- European Satellite Navigation System )3230(MEO)3200512GIOVE - Galileo In-Orbit Validation Element (Giove )2006-2008

(Quasi-Zenith Satellite System, QZSS)GPS : http://www.gps.re.kr/outline/outline_25.asp82008 3

(CNSS)1994 2000 2003 : 91242006

(: http://www.navchina.com)

100: (SA)(SA GPS15: (SA)3 5: GPS (DGPS) < 3: GPS. e.g. WAAS, EGNOS

+

(SBAS) (Satellite Based Augmentation System) (LBAS)(Land Based Augmentation System)

(SBAS)(: http://www.environmental-studies.de/Precision_Farming/EGNOS_WAAS__E/3E.html)

(SBAS)(: http://www.environmental-studies.de/Precision_Farming/EGNOS_WAAS__E/3E.html)

(LBAS)(Land Based Augmentation System)

(LBAS) (Land Based Augmentation System)GPSGPS

(CORS)(Continuously Operating Reference Station)(: http://www.ngs.noaa.gov/CORS/cors-data.html)

12(CORS) 24GPS

12(CORS)

: : ( ) :

(X,Y,Z,t)(X,Y,Z,t)X,Y,Z(X,Y,Z,t)(X,Y,Z,t)X,Y,Z

GPS(X,Y,Z,t)1-3 (X,Y,Z,t)(X,Y,Z,t)(X,Y,Z,t)(X,Y,Z,t)

(RTK)(X,Y,Z,t)(X,Y,Z,t) (X,Y,Z,t)(X,Y,Z,t)(X,Y,Z,t)

(Network-RTK)(X,Y,Z,t)(X,Y,Z,t)(X,Y,Z,t)(X,Y,Z,t)+ +(X,Y,Z,t)

RTKGPSGPSGPS

(26.7.2005 8:51am)

(26.7.2005 9:54pm)