I-NAD 27 noma i-WGS84 ???

Nakuba esikhathini esithile esidlule ama-Geographic Institutes e-Latin America enza isikhulu ushintsho ku-wGS84 njengendlela yokulinganisa okulinganiselwe, ushintsho ezingeni lokusebenzisa lihamba kancane. Empeleni kwelivi cylindrical kuhlale futhi ushintsho kuphela kuhilela ukushintsha Datum phakathi NAD27 futhi NAD83, naphezu nemithelela abe eziyinkimbinkimbi ngokwengeziwe ukuhambisa iyunifomu Vector amabalazwe. Phakathi kwezizathu ezibaluleke kakhulu ezithinta ukulinganisa kukhona okulandelayo:

1. Iningi le-cartography ekhona kumazwe amaningi ase-Hispanic aseNAD27, futhi umkhiqizo omncane ukhiqizwe ekuqalisweni okusha. Ngakho-ke, into elula akumele iphoqele impilo yakho futhi isebenzise ulwazi kumafomethi amaningi kakhulu.

2. Ngezinhloso “zokudwetshwa kwezithombe”, izikhathi eziningi akuthinteki ukusebenzisa zombini izinhlelo, isici esiyingozi ngoba kwezinye izimo ukwaziswa kuba “amamephu aqoshiwe“. Kodwa-ke, thina esisebenza ngendlela kamasipala, njenge-cadastre, isici sokuqagela sibalulekile, uma ufuna ukuphatha amagama ukhiye we-cadastral ngaphansi kwesigatshana sama-quadrants; ngoba lezi zinhlobo zombili izinhlelo zihlukile, okusho ukuthi ukuguqulwa kwempahla ukushintsha uma sisuka kwesinye isimiso siya kwesinye. Ukwengeza, i-GPS entsha kakhulu ayilethe konke okukhethwa kukho kokuboniswa kwe-NAD27.
2. Ukuzimela ukuthi izimo zikahulumeni ezengeziwe kuthinteka ukungabi nobuholi kunxenye yezinhlaka ezilawulayo ezindabeni zokudweba nokuhleleka kwezindawo. Nakuba izinguquko aziwa projection entsha olusemthethweni iminyaka eminingi, kwezinye izimo kudinga kancane ukusho, ngoba kufanele kube idatha inter-lwezendawo ukuthi ungakwazi ukulawula kungani ukufana kwelivi amakomiti ukuphathwa kazwelonke. Ukulahlekelwa ubuholi ekhulwini esanda zokugcina, ngemva US wezempi lingaqaphile bukhicite ukushiyeka ezinkulu kwamanye amazwe kuphela ningilabo okubhaliwe noma nezakhiwo analog ngaphandle rush uthuthe kokushicilela ubuchwepheshe ulwazi ngokuya kwesikhathi.

I-3 Iqiniso lokuthi izinhlelo eziningi zekhompyutha azikho inkinga ku idatha yokulahla ngendiza Yenza isimiso singasheshi. Nokho hhayi reprojection ngokwanele, ngezinye izikhathi kuyadingeka elifanele ilwazi, ngoba ezimweni eziningi lokho kwenziwa kuyinto ukuhambisa iyunifomu yangokwesiko amamitha eziningi enyakatho futhi abaningi Vector empumalanga, Nokho reprojection kuhilela okungaphezu ukuthi kuye kwezinga nokuhambisana kwedatha.

Kungenzeka ukuncintisana noma ukwenza izinto zibe lula nge-Google Earth, nginguye ngubani othi lokhu okulandelayo ngosizo lwakhe:

• Ngokujwayelekile, idatha oyifaka kuyo Google Earth zidalwe ngesistimu ethile yokuhlela indawo, njenge-Universal Transverse Mercator (UTM) nokuqalwa kanye a i-datum I-NAD27 (i-datum eNyakatho Melika ye-1927)

• Okwamanje, i-Google Earth ayisekeli amafayela asebenzisa ukucaciswa kwe-NAD83.