GPS teebmeem
May 12, 2017| GPS (Thoob ntiajteb Positioning System) yog hu ua "Global Positioning Systems". Nws yog ib tiam tshiab ntawm satellite navigation system nrog thoob ntiaj teb nruam positioning thiab dua precision 3d positioning, uas tau raug muab tso rau hauv siv 1992. GPS muaj peb ntu: qhov chaw qhov, hauv kev soj ntsuam hauv av thiab neeg siv khoom. GPS yog cov satellite launching ob hom pseudo random code mus nqa tawm ntawm qhov chaw ntsuas. Cov kab lus ob-pseudo-random yog p-code thiab C / A code. P code yog txoj cai ntsuas kev cai, tshwj xeeb tshaj yog rau cov tub rog Asmeskas cov tub rog, tsis tshua paub meej, ua tiav 3m (2DMS). C / A code yog sib npaug sounding code, yog pej xeem, tus precom qhia precision yog lub dav hlau chaw precision 100m (2DMS), qhov siab precision yog 157m (2 dms). Rau pej xeem cov neeg siv, kev siv cov cuab yeej technology GPS sib txawv ua tau zoo dua qhov chaw mus rau ob peb lub metres. Tam sim no, GPS tau ua tus tseem ceeb navigation system, GPS receiver tau dav nrog ntau hom nkoj, qhov sib txawv GPS receiver tau nyob hauv ib co ships nruab.