I-astrolabe sisixhobo esisebenzisa indawo apho zimikhona iinkwenkwezi okanye ilanga. Yayisetyenziswa ngokusesikweni kwi- navigation ukunceda iintloli nabakhenkethi baselwandle ukuze babone okokuba baphi na kanye. Umgama phakathi komntla nomzantsi we-equator bawufumana ngomlinganiselo womgama ophakathi kwelanga neenkwenkwezi ngaphaya kwe-horizon. Ii-Astronomers zisebenzisa ezinye iintlobo zee- astrolabes, ezidla ngokuba zezinkulu kunezinye.