I-Geobide, ED50 ne-ETRS89 Coordinate System Transformation
Ukuthatha ithuba lokulandela phezulu Amandla we-Geobide Suite, sizobona izinketho zokuguqula phakathi Izinhlelo Zokubhekisela. Ithakazelise kulabo kumele uguqule phakathi Datum ezahlukene kuleli cala sizobona indlela yokukwenza nge ED50 futhi ETRS89 izinhlelo cishe isimo esifanayo e-Latin America phakathi NAD27 futhi WGS84.
Ingabe idatha idluliselwe?
Lokhu akulona iqiniso leGoogle Earth, lapho kuguqulwa khona izinguquko eziningi, izithombe eziningi zishiyiwe, into ethi ungabheka ku-overlaps phakathi kokuthatha okuhlukile; Kodwa-ke, emazweni amaningi, ezifundazweni noma emiphakathini ezimele, izikhungo zomphakathi zinikeze iGoogleEarth ngemifanekiso yazo ngokuma okuqondile, ngobubi iGoogleEarth isebenzisa i-WGS84 njenge-Datum ejwayelekile, ngakho-ke ukusebenzisa idatha kolunye uhlelo kudinga ushintsho. Inguquko incike okokuqala kunencazelo yayo kepha futhi nasendaweni esizithola sikuyo. Kungakho amasistimu ejwayelekile enganikezeli ngemingcele ekhethekile yendawo ngayinye.
Masithathe njengesibonelo uguquko lwe-ED50-30N (EPSG: 23030) luye ku-ETRS89-30N (EPSG: 25830) yeNavarra, neSpain. Incazelo ejwayelekile yenguquko inezinga elihlukile lokunemba ngokuya ngendawo okusetshenziswe kuyo. Ngalesi sizathu, kunamapharamitha angeziwe, angayi encazelweni ejwayelekile nokuthi ku-Navarra ngokwesibonelo amanye kodwa e-Asturias angaba namanye amanani ahlukile.
Uma sibheka isithombe esingenhla esithwetshulwe kwaGeomap, sibona imephu enezendlalelo ezimbili (i-orthophoto nephasela) ezihanjisiwe ngokuhlobene. Kungumphumela wokuphrojusa iNavarra Cadastre ku-ED-50N endizeni isendlalelo se-GoogleMaps ku-WGS84 kanye nokuthuthwa komphumela okuholelekile kuhlobene nenkinga echazwe esigabeni esandulele.
Isifundo sakamuva seGeobide, esisebenzisa kuso lesi sihloko manje sishicilela okungenani izindlela ezi-4 zokuyilungisa ,. NgeGeobide, manje kungenzeka ukukhombisa ukuguqulwa kwedatha kwenguquko phakathi kwe-Coordinate Systems ngezindlela ezine ezihlukile:
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Izinguquko ezijwayelekile:
Lolu khetho lusetshenziselwa ukuguqulwa okujwayelekile ngaphandle kwemingcele yendawo, futhi kunembile kunembile. Nge-Navarre, isibonelo, ukuhamba kusuka ku-ED50 kuya ku-ETRS89 kunephutha ye- ~ 100-200m ku-x no-y. (Ukukhumbula ukuthi lokhu akusho ukuphazamisa izinhlelo zokuhlela nge-datum efanayo).
Iyafana kunjalo NAD27 nge WGS84 ukuhamba futhi 202 amamitha enyakatho futhi 6 amamitha empumalanga eCentral endaweni izinguquko ushintsha latitude, nakuba kuyaphawuleka kuphela latitude livela Ecuador ngenkathi ubude bungalutho buvela empumalanga yamanga.
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Ukuguqulwa usebenzisa igridi ye-NTv2:
Lolu khetho lusebenzisa igridi ngamagugu ukulungisa ukuguqulwa nge-interpolation eqondile. Lolu khetho lungcono kakhulu kunendlela yokuqala futhi lamukelwe yi-IGN. Kuyacaca ukuthi, uma sinegridi yomsebenzi wethu.
Izicelo ze I-Geobide Manje banikela ngamagridi amabili ahlinzekwa yi-IGN ngeSpain, ahlanganisa iPeninsula neBalearic Islands, futhi ashicilelwa ngo-2003 nango-2009. Umsebenzisi angakhetha kalula igridi azoyisebenzisa.
Ku-Intanethi ungathola ama-grid amaningi, ngisho nasemhlabeni wonke, kodwa ngosayizi awatholakali ngokuzenzakalela ekulandweni kohlelo lweGeobide.
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Ukuguqulwa kwe-Molodensky (indlela ye-3-imingcele):
Sebenzisa amanani we-offset ye-3 kumsuka phakathi kwe-ellipsoids. Kuzo zokusebenza, umsizi olungiselelwe ngaphambilini ophakanyisiwe ngu babela for Spain.
I-Bursa-Wolf Transformation (i-7-parameters indlela)
Le nguquko isebenzisa amanani we-7 wokuguqula phakathi kwama-ellipsoids. Imingcele yokungena yilezi: Ukususwa (i-Dx, i-Dy, i-Dz), i-Rotation (i-Rx, i-Ry, i-Rz) ne-Scale factor (μ)
Kuzo zokusebenza I-Geobide Ama-pre-configured 3 anconywe yi- babela i-Northwest, Central Zone neMpumalanga ye-Peninsula, ngokulandelana.
Iziphumo
Njengoba ungabona imiphumela ayifani kakhulu phakathi kwezindlela zokugcina ze-3, kodwa ngeyokuqala. Yingakho kufanele wazi ukuthi ukuguqulwa kudinga noma iyiphi yalezi zindlela eziphambili.
Phakathi ED50-xxN (EPSG: 230xx) amasistimu ETRS89-xxN (EPSG: 258xx) endaweni of Spain ngokwalo kumele isetshenziswe njengoba Datums / ellipsoids ED50 futhi ETRS89 / WGS84 akuzona okulingana.
Ngokwesibonelo, uma Geomap hhayi lezi eziphambili idatha isethi, idatha kusuka Navarra e ED50-30N (EPSG: 23030) reprojected epheshaneni ku idatha ahlinzekwa yi-Google Maps (ellipsoid WGS84) ngeke wathutha. Ukuze uphile kahle, kuyadingeka ukusebenzisa ukuguqulwa okuqondile okuveziwe kakade.
Ngizizwa okuhle kakhulu ukuthi Geobide wenze imizamo ebalulekile nje kuphela ukushiya amakhono ukuba isistimu yakho, kodwa futhi wokuloba imininingwane kancane ngaphezulu lolu daba ngoba kungaba nomthelela kakhulu ikhwalithi nobuqotho lomsebenzi, ngaphandle nje baqonde nabo Kungenye umzamo.
Kuze kube manje, konke lokhu kuhlanganisiwe ngokuzenzakalela ku injini, kodwa njengoba senza ubeke abangane sika Geobide, izimfuno msebenzisi wabaholela ukushiya ebonakalayo izicelo umsebenzisi ukuzazi lezi ngisho ukushintsha ukucushwa okuzenzakalelayo, noma ukubeka omunye endaweni yakho yomsebenzi.
Ukuguquguquka kwe-ellipsoidal / geoidal high
Kule nguqulo entsha i-ellipsoidal / geoidal ukuphakama umehluko ibhokisi lokubala liye lashintshwa ukuze umsebenzisi manje angakhetha imodeli ye-geoid ezosetshenziswa.
Ifayela lama-nomenclatures PRJ
Futhi ekugcineni, enye inguquko engicabanga ukuthi inhle kuwe umzamo wokusebenzisana ngezindinganiso ze-OGC noma imikhuba yezinhlelo eziphakanyisiwe. Amafayela we-PRJ akhiqizwa nguGeobide asesimweni segama le-OGC WKT, okuyinto evamile ehlonishwa ngamathuluzi amaningi we-CAD / GIS. Akunjalo kwezicelo ze-ESRI, i-PRJ, nakuba iqukethe incazelo efanayo yemathematika njengezinyathelo ezijwayelekile, ihlanganisa izinhlelo zoMxhumanisi ngokuhlukile.
Isibonelo:
Ngo okuqukethwe ifayela PRJ OGC, le ETRS89-30N uhlelo (EPSG: 25830) ebizwa ngokuthi igama lekhodi "ETRS89 / UTM zone 30N"; izicelo ESRI, kunalokho, bakubiza ngokuthi "ETRS_1989_UTM_Zone_30N". Uma ku-ArcGis sihlanganisa izingqimba nge-PRJs kulezi ziphakamiso ezimbili lezi software zizokwenza ushintsho lwendawo ngisho nalapho incazelo yezibalo ze-Coordinate Systems ifana.
Ukunaka lokhu inkani, I-Geobide inikwe amandla ukhetho olusha ku-selector system yokukhetha ukuze umsebenzisi angabonisa uma efuna uhlelo lwe-Coordinate ne-PRJ kwisitayela se-EPSG noma isitayela ESRI.
