天地图切图Schema研究

本文只是在技术上猜测,没有任何根据,如想使用天地图服务,请直接联系天地图公司。

天地图是中国区域内数据资源最全的地理信息服务网站,同时将为公众提供权威、可信、统一的地理信息服务,在我国的公共服务平台建设中将起到重要作用,那么为了在其他系统中使用天地图的地图服务,就很有必要对天地图的切图schema研究一番。

下面就把天地图切图schema的主要参数列举一下:

1 参考系 :wgs84 (4326)

2 切图原点(-180,90)

3 切图范围(-180,-90,180,90)

4 切图级别18级,比例尺和分辨率分别为:
{“level” : 1, “resolution” : 0.3515625, “scale” : 147748799.285417},
{“level” : 2, “resolution” : 0.17578125, “scale” : 73874399.6427087},
{“level” : 3, “resolution” : 0.087890625, “scale” : 36937199.8213544},
{“level” : 4, “resolution” : 0.0439453125, “scale” : 18468599.9106772},
{“level” : 5, “resolution” : 0.02197265625, “scale” : 9234299.95533859},
{“level” : 6, “resolution” : 0.010986328125, “scale” : 4617149.97766929},
{“level” : 7, “resolution” : 0.0054931640625, “scale” : 2308574.98883465},
{“level” : 8, “resolution” : 0.00274658203125, “scale” : 1154287.49441732},
{“level” : 9, “resolution” : 0.001373291015625, “scale” : 577143.747208662},
{“level” : 10, “resolution” : 0.0006866455078125, “scale” : 288571.873604331},
{“level” : 11, “resolution” : 0.00034332275390625, “scale” : 144285.936802165},
{“level” : 12, “resolution” : 0.000171661376953125, “scale” : 72142.9684010827},
{“level” : 13, “resolution” : 8.58306884765629E-05, “scale” : 36071.4842005414},
{“level” : 14, “resolution” : 4.29153442382814E-05, “scale” : 18035.7421002707},
{“level” : 15, “resolution” : 2.14576721191407E-05, “scale” : 9017.87105013534},
{“level” : 16, “resolution” : 1.07288360595703E-05, “scale” : 4508.93552506767},
{“level” : 17, “resolution” : 5.36441802978515E-06, “scale” : 2254.467762533835},
{“level” : 18, “resolution” : 2.68220901489258E-06, “scale” : 1127.2338812669175}
5 切图参数:
格式:png
大小:256*256
dpi:96
6 服务器个数:8个,分别为:
http://tile0.tianditu.com/
http://tile1.tianditu.com/
http://tile2.tianditu.com/
http://tile3.tianditu.com/
http://tile4.tianditu.com/
http://tile5.tianditu.com/
http://tile6.tianditu.com/
http://tile7.tianditu.com/

7 切片请求方式:REST
8 切片请求地址http://tile0.tianditu.com/DataServer?T=AB0512_Anno&X=1&Y=0&L=2
其中x为列数,y为行数,l为级别

关于如何得到这些参数,可以负责任的说,经验!
下面使用ArcGIS API for iOS来加载天地图,用来验证上面的参数,直接放图:

This entry was posted in ArcGIS, ArcGIS API for iOS, iOS.

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