▁Sat ellite ▁System ▁( GN SS ) ▁resulted ▁in ▁its ▁not ▁being ▁adopted ▁in ▁civil ▁av iation . ▁▁▁▁ ▁At ▁the ▁time ▁I LS ▁and ▁M LS ▁were ▁the ▁only ▁standard ized ▁systems ▁in ▁Civil ▁A viation ▁that ▁meet ▁requirements ▁for ▁Category ▁III ▁autom ated ▁land ings . ▁The ▁first ▁Category ▁III ▁M LS ▁for ▁civil ▁av iation ▁was ▁commission ed ▁at ▁He ath row ▁air port ▁in ▁March ▁ 2 0 0 9 ▁and ▁removed ▁from ▁service ▁in ▁ 2 0 1 7 . ▁ ▁Trans ponder ▁Land ing ▁System ▁( T LS ) ▁can ▁be ▁used ▁where ▁a ▁conventional ▁I LS ▁cannot ▁work ▁or ▁is ▁not ▁cost - effect ive . ▁ ▁Local izer ▁Performance ▁with ▁Vert ical ▁guidance ▁( LP V ) ▁is ▁based ▁on ▁the ▁W ide ▁Area ▁Aug ment ation ▁System ▁( WA AS ), ▁LP V ▁has ▁similar ▁min ima ▁to ▁I LS ▁for ▁appropri ately ▁equ ipped ▁aircraft . ▁, ▁the ▁F AA ▁has ▁published ▁more ▁LP V ▁approaches ▁than ▁Category ▁I ▁I LS ▁procedures . ▁ ▁Gr ound - B ased ▁Aug ment ation ▁System ▁( GB AS ) ▁( Local ▁Area ▁Aug ment ation ▁System ▁in ▁the ▁United ▁States ) ▁is ▁a ▁safety - crit ical ▁system ▁that ▁aug ments ▁the ▁G N SS ▁Standard ▁Position ing ▁Service ▁( SP S ) ▁and ▁provides ▁en hanced ▁levels ▁of ▁service . ▁It ▁supports ▁all ▁phases ▁of ▁approach , ▁landing , ▁departure , ▁and ▁surface ▁operations ▁within ▁the ▁V H F ▁coverage ▁volume . ▁GB AS