. ▁The ▁distance ▁from ▁the ▁run way ▁at ▁which ▁this ▁indic ation ▁should ▁be ▁received ▁is ▁published ▁in ▁the ▁documentation ▁for ▁that ▁approach , ▁together ▁with ▁the ▁height ▁at ▁which ▁the ▁aircraft ▁should ▁be ▁if ▁correctly ▁established ▁on ▁the ▁I LS . ▁This ▁provides ▁a ▁check ▁on ▁the ▁correct ▁function ▁of ▁the ▁gli de ▁slope . ▁In ▁modern ▁I LS ▁install ations , ▁a ▁D ME ▁is ▁installed , ▁co - located ▁with ▁the ▁I LS , ▁to ▁augment ▁or ▁replace ▁marker ▁be a cons . ▁A ▁D ME ▁continu ously ▁displays ▁the ▁aircraft ' s ▁distance ▁to ▁the ▁run way . ▁ ▁D ME ▁substitution ▁ ▁Dist ance ▁meas uring ▁equipment ▁( D ME ) ▁provides ▁pil ots ▁with ▁a ▁sl ant ▁range ▁measurement ▁of ▁distance ▁to ▁the ▁run way ▁in ▁na ut ical ▁miles . ▁D ME s ▁are ▁augment ing ▁or ▁replacing ▁markers ▁in ▁many ▁install ations . ▁The ▁D ME ▁provides ▁more ▁accurate ▁and ▁continuous ▁monitoring ▁of ▁correct ▁progress ▁on ▁the ▁I LS ▁gli de ▁slope ▁to ▁the ▁pilot , ▁and ▁does ▁not ▁require ▁an ▁installation ▁outside ▁the ▁air port ▁boundary . ▁When ▁used ▁in ▁conj unction ▁with ▁an ▁I LS , ▁the ▁D ME ▁is ▁often ▁s ited ▁mid way ▁between ▁the ▁reci pro cal ▁run way ▁th resh olds ▁with ▁the ▁internal ▁delay ▁modified ▁so ▁that ▁one ▁unit ▁can ▁provide ▁distance ▁information ▁to ▁either ▁run way ▁threshold . ▁For ▁approaches ▁where ▁a ▁D ME ▁is ▁specified ▁in ▁lieu ▁of ▁marker ▁be a cons , ▁D ME ▁Re