blitz.r

## Load required packages
# you will need to install these, first do
# eg.   install.packages("tidyverse")
# etc. to install them one by one
library(tidyverse)
library(httr)
library(sf)
library(tmap)


########## SETUP ################

# Blitzortung user name and password
username = "xxxxx"
password = "xxxxx"

# Blitzortung station code
# Note it does a pretty dumb grep for station code to isolate it
# If you have like a 2-digit station code this will probably 
# work poorly. 4-digit should be fine
station_code="2050"

# How many hours to plot
n_hours = 12

# Blitzortung region data to use, eg. Oceania = "Data_2", North America = "Data_3"
region = "Data_3"

##################################

# Default world map
data(World)
World = st_as_sf(World)

# Plot all points your station has helped with in the lat 12 hours
lst=list()
j=0
for(i in seq(-60*n_hours,-10,10)){
  j=j+1
  time_now=Sys.time()+i*60
  year = format(time_now,"%Y",tz="GMT")
  month = format(time_now,"%m",tz="GMT")
  day = format(time_now,"%d",tz="GMT")
  hour = format(time_now,"%H",tz="GMT")
  mint = as.numeric(format(time_now,"%M",tz="GMT"))
  mint=floor(mint/10)*10
  mint = as.character(mint)
  if(mint=="0"){mint="00"}
  url = sprintf("http://data.blitzortung.org/%s/Protected/Strokes/%s/%s/%s/%s/%s.log",region,year,month,day,hour,mint)
  dat=GET(url,authenticate(username,password))
  dat=content(dat,as="text")
  dat = unlist(strsplit(dat,"\n"))

  stpos = str_extract(dat,"(?<=pos;)(.*)(?=str)")
  lat =stpos %>% str_split(";") %>% map(1) %>% unlist() %>% as.numeric()
  lon =stpos %>% str_split(";") %>% map(2) %>% unlist() %>% as.numeric()

  datx = tibble(lat = lat,lon=lon,sel=0)

  stion = str_extract(dat,"(?<=sta;)(.*)") %>% str_detect(station_code)
  datx = datx[stion,]
  lst[[j]]=datx
}
datx=bind_rows(lst)

dats = st_as_sf(datx,coords=c("lon","lat"),crs=4326)
mp = tm_shape(World) + tm_polygons() + tm_shape(dats,is.master = TRUE) + tm_dots(col="red",scale=2) + tm_compass() + tm_grid() + tm_layout(bg.color = "lightblue")
mp