百度地图瓦片基本参数计算

打算把目前知道的瓦片切片方式做个汇总，看到百度的，绕晕乎了，下表不知道是不是完全正确，红色的为可以从瓦片服务器抓到图的

还有个地方不是很明白，取了第3级的30张图，然后我就不明白了，为啥是横5张*纵6张，难道百度的纬度范围少截取了一些，没有保证投影后的正方形？

下表是按正方形投影范围计算的

ZTilesPixelsPixelSize(Deg)PixelSize(Mtr)PPIScale0123061.17743980920114E+00131072.0000000000000096.00000000000000495390236.22047200000000246125.88719904600570E-0165536.0000000000000096.00000000000000247695118.110236000000003612232.94359952300285E-0132768.00000000000000 96.00000000000000 123847559.05511800000000 41024461.47179976150142E-0116384.00000000000000 96.00000000000000 61923779.52755910000000 52048927.35899880750712E-028192.00000000000000 96.00000000000000 30961889.76377950000000 64097843.67949940375356E-024096.00000000000000 96.00000000000000 15480944.88188980000000 778195681.83974970187678E-022048.00000000000000 96.00000000000000 7740472.44094488000000 8154391369.19874850938390E-031024.00000000000000 96.00000000000000 3870236.22047244000000 9306782724.59937425469195E-03512.00000000000000 96.00000000000000 1935118.11023622000000 106121565442.29968712734597E-03256.00000000000000 96.00000000000000 967559.05511811000000 1112243130871.14984356367299E-03128.00000000000000 96.00000000000000 483779.52755905500000 1224466261735.74921781836494E-0464.00000000000000 96.00000000000000 241889.76377952800000 13489212523452.87460890918247E-0432.00000000000000 96.00000000000000 120944.88188976400000 14978425046891.43730445459123E-0416.00000000000000 96.00000000000000 60472.44094488190000 151956850093787.18652227295617E-058.00000000000000 96.00000000000000 30236.22047244090000 1639136100187553.59326113647809E-054.00000000000000 96.00000000000000 15118.11023622050000 1778272200375091.79663056823904E-052.00000000000000 96.00000000000000 7559.05511811024000 18156544400750178.98315284119521E-061.00000000000000 96.00000000000000 3779.52755905512000 19313088801500344.49157642059761E-060.50000000000000 96.00000000000000 1889.76377952756000