Waa maxay nidaamka geodeysiga?
Geodetic datum ama geodetic system (sidoo kale: geodetic reference datum, geodetic reference system, ama geodetic reference frame) waa datum caalami ah oo tixraac ah ama qaab tixraac ah oo si sax ah u matalaya booska meelaha dhulka ama meelaha kale ee meeraha iyadoo la adeegsanayo isku-xidhka geodetic. Taariikhdu waxay muhiim u tahay tiknoolajiyad kasta ama farsamo kasta oo ku saleysan goobta meelaha, oo ay ku jiraan geodesy, navigation, sahaminta, nidaamyada macluumaadka juqraafiyeed, maqalka fog, iyo khariidaynta. Xisaab-xigeenka toosan waxaa loo isticmaalaa in lagu cabbiro goob ka mid ah dusha sare ee dhulka, latitude iyo longitude ama nidaam kale oo isku xiran; Xisaab-xigeenka toosan waxaa loo isticmaalaa in lagu cabbiro dhererka ama qoto dheer ee la xiriira asalka caadiga ah, sida heerka badda ee celceliska (MSL). Tan iyo markii uu soo ifbaxay nidaamka meelaynta caalamiga ah (GPS), ellipsoid iyo datum WGS 84 oo ay isticmaasho ayaa badalay inta badan kuwa kale ee codsiyada badan. WGS 84 waxaa loogu talagalay isticmaalka adduunka oo dhan, si ka duwan inta badan taariikhihii hore.