Japan Digital Elevation Model [DEM]

For the Regional Systems Analysis of Japan, the GTOP0 30 arc second resolution data tiles were projected into Lambert Comformal Conic projection using Clarke 1866 datum, with units in meters. The details for this are: Units: meters Central meridian: 135 E Standard parallel #1: 39 N Standard parallel #2: 27 N Latitude of origin: 33 N Datum: Clarke 1866 Cell size: 846 m Subsequently the DEM tiles were trimmed to the islands of Japan (including Hokkaido and the Senkyaku Chain) and reprojected into a Geographic Coordinate System decimal degrees WGS-84 version. The cell size in decimal degrees of the distributed WGS-84 version is 0.010215556.

针对日本区域系统分析，采用Clarke 1866基准面（Clarke 1866 datum）将GTOP0 30弧秒分辨率数据瓦片投影至兰勃特正形圆锥投影（Lambert Comformal Conic projection），单位为米。具体投影参数如下：单位：米；中央经线：东经135°；第一标准纬线：北纬39°；第二标准纬线：北纬27°；原点纬度：北纬33°；基准面：Clarke 1866；像元尺寸：846米。随后将数字高程模型（Digital Elevation Model, DEM）瓦片裁剪至日本列岛（含北海道及仙觉群岛（Senkyaku Chain））范围，并重新投影至采用十进制度数的WGS-84地理坐标系。该WGS-84版本数据的像元尺寸为0.010215556（十进制度数）。