▁in ▁the ▁non - Mus lim ▁real ms . ▁The ▁" B alk h ī ▁school ", ▁which ▁included ▁ge ograph ers ▁such ▁as ▁Est akh ri , ▁al - M u q add asi ▁and ▁I bn ▁Haw q al , ▁produced ▁world ▁at l ases , ▁each ▁one ▁featuring ▁a ▁world ▁map ▁and ▁twenty ▁regional ▁maps . ▁ ▁Su hr ā b , ▁a ▁late ▁ 1 0 th - century ▁Muslim ▁ge ograph er , ▁accompanied ▁a ▁book ▁of ▁ge ographical ▁coordinates ▁with ▁instructions ▁for ▁making ▁a ▁rect angular ▁world ▁map , ▁with ▁equ irect angular ▁projection ▁or ▁cyl ind rical ▁equ id istant ▁projection . ▁The ▁earliest ▁surv iving ▁rect angular ▁coordinate ▁map ▁is ▁dated ▁to ▁the ▁ 1 3 th ▁century ▁and ▁is ▁attributed ▁to ▁Ham dal lah ▁al - M usta q fi ▁al - Q az w ini , ▁who ▁based ▁it ▁on ▁the ▁work ▁of ▁Su hr ā b . ▁The ▁orthogonal ▁parallel ▁lines ▁were ▁separated ▁by ▁one ▁degree ▁intervals , ▁and ▁the ▁map ▁was ▁limited ▁to ▁South west ▁Asia ▁and ▁Central ▁Asia . ▁The ▁earliest ▁surv iving ▁world ▁maps ▁based ▁on ▁a ▁rect angular ▁coordinate ▁grid ▁are ▁attributed ▁to ▁al - M ust aw fi ▁in ▁the ▁ 1 4 th ▁or ▁ 1 5 th ▁century ▁( who ▁used ▁in ver val s ▁of ▁ten ▁degrees ▁for ▁the ▁lines ), ▁and ▁to ▁H af iz - i ▁Ab ru ▁( d ied ▁ 1 4 3 0 ). ▁ ▁I bn ▁Batt uta