Day: December 29, 2018

The size and the color of a dot shows the SNR of a received FT8 signal.

import cartopy.crs as ccrs
import matplotlib.pyplot as plt
import numpy as np
import re
import datetime

def maiden2lonlat(maiden: str):
    n = len(maiden)
    maiden = maiden.lower()
    print(maiden, n)
    aaa = ord('a')
    lon = -180.0
    lat = -90.0

    lon += (ord(maiden[0])-aaa)*20.0
    lat += (ord(maiden[1])-aaa)*10.0
    lon += int(maiden[2])*2.0
    lat += int(maiden[3])*1.0
    if n >= 6:
        lon += (ord(maiden[4])-aaa) * 5.0/60.0
        lat += (ord(maiden[5])-aaa) * 2.5/60.0
    if n >= 8:
        lon += int(maiden[6]) * 5.0/600.0
        lat += int(maiden[7]) * 2.5/600.0
    return lon, lat


ax = plt.axes(projection=ccrs.PlateCarree())
ax.stock_img()
 
fnames = ['station1.adif']
 
def parse_adif(fn):
    raw = re.split('<eor>|<eoh>',open(fn).read() )
    raw.pop(0)
    raw.pop()
    logbook =[]
    for record in raw:
        qso = {}
        tags = re.findall('<(.*?):\d+.*?>([^<\t\n\r\f\v]+)',record)
        for tag in tags:
            qso[tag[0]] = tag[1]
        logbook.append(qso)    
    return logbook

def mydatetime(date, time):
    dt = datetime.datetime(int(date[0:4]), int(date[4:6]), int(date[6:8]), \
                           int(time[0:2]), int(time[2:4]), int(time[4:6]))
    return dt

dt0 = datetime.datetime(2001,  1,  1,  0, 0 ,  0)
dt9 = datetime.datetime(2099, 12, 31, 23, 59, 59)

x = []
y = []
r = []
c = []
fcount = 0
for fn in fnames:
    log = parse_adif(fn)
    scount = 0
    for qso in log:
        if ('GRIDSQUARE' in qso):
            dt = mydatetime(qso['QSO_DATE'], qso['TIME_ON'])
            if dt >= dt0 and dt <=dt9:
                grid = qso['GRIDSQUARE']
                mylon, mylat = maiden2lonlat(grid)
                if ('APP_PSKREP_SNR' in qso):
                    snr = float(qso['APP_PSKREP_SNR'])
                    print(fcount, scount, grid, mylon, mylat, snr)
                    x.append(mylon)
                    y.append(mylat)
                    r.append(50.0+2.0*snr)
                    c.append(-snr*30.0)
                    scount += 1
    fcount += 1
plt.scatter(x, y, c=c, s=r, cmap='hsv', alpha=0.5)
plt.show()

---

In the above figure, the colors show the time of the day.

A colormap named “jet” is employed.

The leftmost part corresponds to 00Z, and the rightmost 23Z.

Cartopy is a Python package designed for geospatial data processing in order to produce maps and other geospatial data analyses.

Starting in 2016, Basemap came under new management. The Cartopy project will replace Basemap, but it hasn’t yet implemented all of Basemap’s features. All new software development should try to use Cartopy whenever possible, and existing software should start the process of switching over to use Cartopy.

import cartopy.crs as ccrs
import matplotlib.pyplot as plt
import numpy as np

ax = plt.axes(projection=ccrs.PlateCarree())
ax.stock_img()

n=50
x = 360.0 * np.random.rand(n) - 180.0
y = 120.0 * np.random.rand(n) -  60.0
r =  50.0 * np.random.rand(n) +  20.0

plt.scatter(x, y, c=x, s=r, cmap='hsv', alpha=0.75)
plt.show()