Howcanyoutellwhichdirection?Byday,lookfortheSun.Itisintheeastinthemorningandthewestintheafternoon.Atnight,usetheBigDippertohelpyoufindtheNorthStar.Itwouldbebettertobringacompassbecauseitsneedlealwayspointsnorth.
Howdoyouknowhowfaryouhavegone?Youcouldcounteverystep.Eachstepisabouttwofeet.You’dbetterwearapedometerwhichisatoolthatcountssteps.Ifyouknowwhereyoustarted,whichdirectionyouareheading,andhowfaryouhavegone,youcanuseagoodmaptofigureoutexactlywhereyouare.
Todaythereisanewwayfortravelerstofigureoutwheretheyare.ItistheGPS.Ithas24satellitesthatorbittheearthandconstantlybroadcasttheirpositions.SomedayyoumaycarryasmallreceiverasyouhikeanduseGPStofindoutifyouarethereyet!
UsefulWordsandExpressions:
4.GPS=GlobalPositionSystem全球定位系统