大地基准定义文件
Datum_sp.dat文件定义了大地坐标参数，包括名称、半径、离心率。
Datumcha.dat文件用于从一种大地坐标转成另一个大地坐标（本文件包括转换和旋转参数）。
目前只支持Bursawol转换类型，调用
Bursawol.dat文件获得大地坐标转换参数。
可以查找Datum.dat文件来获得ER
Mapper支持的每个大地基准的参考椭球和基准点信息。
支持的投影及其定义文件
除了主要投影文件Project.dat外，每个投影类型都有各自文件来定义相应参数。如果需要增加新的投影，您需要增加投影文件并在Project.dat文件中增加相应条目。每个投影类型的列表和相应的投影定义文件给定如下：
|
albersea.dat |
Albers Equal
Area |
|
azimuted.dat |
Azimuthal
Equidistant |
|
bioconco.dat |
Bipolar
Oblique Conic Conformal |
|
bonne.dat |
Bonne for
North America |
|
borneo.dat |
Rectified
Skew Orthomorphic |
|
cassini.dat |
Cassini-Soldner |
|
coniced.dat |
Conic
Equidistant |
|
danish_utm.dat |
Danish
Universal Transverse Mercator |
|
dutch.dat |
Stereographic (oblique) |
|
gnomonic.dat |
Gnomonic
Projection |
|
grinten.dat |
Van Der
Grinten's Projection (Sphere) |
|
labordom.dat |
Laborde
Oblique Mercator |
|
lambazea.dat |
Lambert
Azimuthal Equal-Area |
|
lambert1.dat |
Lambert
Conformal Conic with One Standard Parallel |
|
lambert2.dat |
Lambert
Conformal Conic with Two Standard Parallels |
|
lamcon2.dat |
Lambert
Conformal Conic with Two Standard Parallels |
|
mercator.dat |
Mercator
Projection |
|
millercy.dat |
Miller
Cylindrical |
|
modpol.dat |
Modified
Polyconic |
|
modstero.dat |
Miller
Stereographic (Sphere) |
|
mollweid.dat |
Mollweide
Projection |
|
nzmapgrd.dat |
Minimum
Error Conformal |
|
obmerc_b.dat |
Hotine
Oblique Mercator |
|
obmerc_c.dat |
Rectified
Oblique Mercator |
|
orthog.dat |
Orthographic
Projection |
|
regpol.dat |
Regular
Polyconic |
|
robinson.dat |
Robinson
Pseudocylindrical |
|
sinusoid.dat |
Sinusoidal
Projection |
|
stereo.dat |
Polar
Stereographic |
|
stm.dat |
Southern
Transverse Mercator |
|
swiss.dat |
Swiss
Cylindrical |
|
tranmerc.dat |
Transverse
Mercator |
|
utm.dat |
Universal
Transverse Mercator |
