坐标参考系

表示坐标参考系，坐标投影与反投影，畸变分析

坐标参考系 (CRS) 为定义现实世界中的位置提供了框架。使用地理坐标参考系 (CRS) 表示经纬度数据，或使用投影坐标参考系 (CRS) 表示 x-y 地图数据。

使用各种投影方法在不同坐标系之间转换坐标。尽管所有投影方法都会导致畸变，但通过选择合适的投影方法，可以保留面积、形状或方向等属性。

函数

`defaultm`	创建或重置地图投影结构
`geotiff2mstruct`	Convert GeoTIFF information structure to map projection structure
`maplist`	基于 `axesm` 的地图投影支持及投影结构
`maps`	列出基于 `axesm` 的地图投影及投影结构
`projlist`	GeoTIFF 信息结构支持 `projfwd` 和 `projinv`
`utmgeoid`	为给定的 UTM 区域选择椭球体
`utmzone`	根据经纬度确定 UTM 区域
`utmzoneui`	Identify UTM zone by clicking map

`projfwd`	将经纬度坐标投影至 x-y 地图坐标系
`projinv`	将 x-y 地图坐标转换为纬度-经度坐标
`vfwdtran`	Transform azimuth on ellipsoid to direction on map
`vinvtran`	Transform direction on map to azimuth on ellipsoid

`mdistort`	Display contours of constant map distortion on `axesm`-based map
`distortcalc`	Distortion parameters for map projections
`tissot`	Project Tissot indicatrices on `axesm`-based map

`rotatem`	Transform vector map data to new origin and orientation
`newpole`	Origin vector to place specific point at pole
`putpole`	Origin vector to place north pole at specified point
`org2pol`	Location of north pole in rotated map

投影摘要与指南
了解工具箱支持的地图投影类型及其分类与属性。
地图投影的三种主要类型
大多数地图投影可根据圆柱体、圆锥体和平面的几何形状分为三类。
Quantitative Properties of Map Projections
Map projections are influenced and constrained by five characteristic properties: shape, distance, direction, scale, and area.
Projection Parameters
Variable projection parameters control the appearance of map projections. Projection parameters include aspect, origin, and scale.

将坐标系转换到不同的投影坐标系
将坐标系从一个投影坐标系转换为另一个使用相同地理坐标系的投影坐标系。
Project and Display Raster Data
Project or unproject raster data by referencing the coordinates to a grid, then display the data.

Create UTM Maps
Create a map for a zone in the Universal Transverse Mercator (UTM) system.
Set UTM Parameters Interactively
You can interact with a map of the world to select a UTM zone and adjust map settings, such as the limits, origin, parallels, and aspect.
Work in UTM Without a Displayed Map
This example shows how to select a UTM zone by specifying the coordinate of a location. You can then create a UTM coordinate system using the suggested ellipsoid vector of the zone.
Use the Transverse Aspect to Map Across UTM Zones
This example shows how to display areas that extend across more than one UTM zone by using the Mercator projection in a transverse aspect.

Map Projections and Distortions
A map projection transforms a curved surface such as the Earth onto a two-dimensional plane. All map projections introduce distortions compared to maps on globes.
Visualize Spatial Error Using Tissot Indicatrices
A standard method of visualizing map projection distortion is to project small circles spaced at regular intervals across the globe.
Quantify Map Distortions at Point Locations
You can calculate quantitative position-specific map error statistics, such as area scale, angular deformation of right angles, and directional scale distortions along meridians and parallels.

Projection Aspect
A projection aspect is the orientation of a map on the page or display screen. An orientation vector controls the map projection aspect.
Rotational Transformations on the Globe
You can redefine a coordinate system and transform all points to the new coordinate system. The transformation can be useful independent of map displays.