将爱尔兰网格（北距和东距）转换为正确的北距和东距

Question

我有一个 CSV 文件，其中包含纬度和经度列。每个数据都在爱尔兰网格坐标系 (Northings & Eastings) 中。如何转换为正确的经纬度？

我所拥有的示例 Latitude 372000 Longitude 332000。

代码

from shapely.geometry import Point
import geopandas as gpd
from geopandas import GeoDataFrame
import pandas as pd

df = pd.read_csv("File.csv", skiprows=0, low_memory=False, encoding='ANSI')

geometry = [Point(xy) for xy in zip(df['longitude'], df['latitude'])]
gdf = GeoDataFrame(df, geometry=geometry)   

#this is a simple map that goes with geopandas
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))

gdf.plot(ax=world.plot(figsize=(10, 6)), color='red', markersize=1.5)

Answer 1

我相信爱尔兰网格使用 CRS 29903（根据 https://georepository.com/crs_29903/TM75-Irish-Grid.html），而 GeoPandas 附带的世界文件使用 CRS 4326。因此您必须将第一个重新投影到第二个，反之亦然.

类似于：

gdf = gdf.to_crs(4326)

或

world = world.to_crs(29903)

然后您可以使用（在此处使用 Jupyter）进行检查：

In: world.crs

Out:

Name: TM75 / Irish Grid Axis Info [cartesian]:

E[east]: Easting (metre)

N[north]: Northing (metre) Area of Use:

name: Europe - Ireland (Republic and Ulster) - onshore

bounds: (-10.56, 51.39, -5.34, 55.43) Coordinate Operation:

name: Irish Grid

method: Transverse Mercator Datum: Geodetic Datum of 1965

Ellipsoid: Airy Modified 1849

Prime Meridian: Greenwich

所以把这些放在一起（假设你的 .csv 的隐式 CRS 真的是 29903，它看起来像这样：

df = pd.read_csv("File.csv", skiprows=0, low_memory=False, encoding='ANSI')
geometry = [Point(xy) for xy in zip(df['longitude'], df['latitude'])]
gdf = GeoDataFrame(df, geometry=geometry, crs= 29903) 
gdf = gdf.to_crs(4326)
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
gdf.plot(ax=world.plot(figsize=(10, 6)), color='red', markersize=1.5)

你会得到如下所示的几何值：

0       POINT (-6.45067 53.35318)
1       POINT (-6.44943 53.35470)
2       POINT (-6.44432 53.35355)
3       POINT (-6.43974 53.34900)
4       POINT (-6.44179 53.34956)

将爱尔兰网格（北距和东距）转换为正确的北距和东距

Convert Irish Grid (Northings & Eastings) to Correct Northings & Eastings

python

latitude-longitude

pandas

geopandas