wide area difference

Wide Area Difference GPS Technology and Its Development and Application in Projects

广域差分GPS技术在工程中的发展和应用

The colliery , as one kind of the mine , is a kind of special geographical area , which is in large scale , wide area , big difference between geological condition and coal seam composition .

煤矿作为矿山的一种，是一种特殊的地理区域，规模庞大，面积较广，地质条件和煤层赋存条件差别很大。