# Python根据站点列表绘制站坐标全球分布图的示例

SNX全球站点坐标文件下载地址：
ftp://igs.gnsswhu.cn/pub/whu/pub/gps/products/YYYY/igsyyPwwww.snx.Z

```# coding=utf-8
# !/usr/bin/env python
'''
Program:plot_global_sitemap.py
Function:根据站点列表绘制站坐标全球分布图
Author:LZ_CUMT
Version:1.0
Date:2021/12/10
'''
from math import pi, sqrt, atan, atan2, sin, cos
import matplotlib.pyplot as plt
import matplotlib as mpl
import cartopy.crs as ccrs
import cartopy.feature as cfeature
from cartopy.mpl.ticker import LongitudeFormatter, LatitudeFormatter

# xyz转换为llh（经纬度）
def xyz2llh(ecef, site):
aell = 6378137.0
fell = 1.0 / 298.257223563
deg = pi / 180
u = ecef[0]
v = ecef[1]
w = ecef[2]
esq = 2*fell-fell*fell
lat = 0
N = 0
if w == 0:
lat = 0
else:
lat0 = atan(w/(1-esq)*sqrt(u*u+v*v))
j = 0
delta = 10 ^ 6
limit = 0.000001/3600*deg
while delta > limit:
N = aell / sqrt(1 - esq * sin(lat0)*sin(lat0))
lat = atan((w / sqrt(u*u + v*v)) * (1 + (esq * N * sin(lat0) / w)))
delta = abs(lat0 - lat)
lat0 = lat
j = j + 1
if j > 10:
break
long = atan2(v, u)
h = (sqrt(u*u+v*v)/cos(lat))-N
llh = [site, long * 180 / pi, lat * 180 / pi, h]
return llh

# 由站点文件获取站点列表存入sitelist
def getSite(listfile):
sitelist = []
f = open(listfile)
while ln:
sitelist.append(ln[0:4].upper())
return sitelist

# 根据站点名在snx文件中搜索XYZ坐标转化为经纬度并输出
def getBLH_single(site,snxlines):
xyz = [0, 0, 0]
for ln in snxlines:
if site in ln:
if 'STAX   ' in ln:
xyz[0] = float(ln[47:68])
if 'STAY   ' in ln:
xyz[1] = float(ln[47:68])
if 'STAZ   ' in ln:
xyz[2] = float(ln[47:68])
blh = xyz2llh(xyz, site)
if len(blh) != 4:
return blh

def getBLH(listfile, snxfile):
siteBLH = []
sitelist = getSite(listfile)
f = open(snxfile)
for site in sitelist:
siteBLH.append(getBLH_single(site, lns))
return siteBLH

def plotsite(siteBLH):
# mpl.rcParams['font.sans-serif'] = ['Helvetical']
mpl.rcParams['axes.unicode_minus'] = False
mpl.rc('xtick', labelsize=9)
mpl.rc('ytick', labelsize=9)
mpl.rcParams['xtick.direction'] = 'in'
mpl.rcParams['ytick.direction'] = 'in'

fig = plt.figure(figsize=(14, 7))
ax = plt.axes(projection=ccrs.PlateCarree(central_longitude=150))
ax.set_extent([-180, 180, -90, 90], crs=ccrs.PlateCarree())
ax.set_xticks([0, 60, 120, 180, 240, 300, 360], crs=ccrs.PlateCarree())
ax.set_yticks([-90, -60, -30, 0, 30, 60, 90], crs=ccrs.PlateCarree())

for site in siteBLH:
ax.plot(site[1], site[2], 'o', color='r', mec='k', mew=0.5, transform=ccrs.Geodetic(), ms=13.0)
plt.text(site[1] + 1.5, site[2] + 1.5, site[0], transform=ccrs.Geodetic(),fontsize='x-large')  # 添加站名标注
plt.xticks(fontsize='x-large')
plt.yticks(fontsize='x-large')
lon_formatter = LongitudeFormatter(zero_direction_label=True)
lat_formatter = LatitudeFormatter()
ax.xaxis.set_major_formatter(lon_formatter)
ax.yaxis.set_major_formatter(lat_formatter)

fig.savefig('global_sitemap.png', bbox_inches='tight', dpi=400)
plt.show()

if __name__ == '__main__':
listfile = r'site.info'               # 输入要画的站点列表文件
snxfile = r'igs21P2177.snx'              # 输入IGS站坐标文件
siteBLH = getBLH(listfile, snxfile)   # 获取所有站点的经纬度
plotsite(siteBLH)           # 画图
print('[INFO] Plot complete!')        # 完成
```