．計(jì)算兩地的經(jīng)度差：(1)如果已知地和所求地同在東經(jīng)或同在西經(jīng),則：經(jīng)度差=經(jīng)度大的度數(shù)－經(jīng)度小的度數(shù)(2)如果已知地和所求地一個(gè)在東經(jīng)另一個(gè)在西經(jīng),則：經(jīng)度差=兩地經(jīng)度相加2．把經(jīng)度差轉(zhuǎn)化為兩地的地方時(shí)差,即：...