This directory contains tools that help in generating the drone restriction maps.

• airports.py - Used to generate restriction zones around airport runways
• ais-sup.pu - Used to periodically fetch and parse AIS supplements for temporary restriction zones

This tool creates a geojson polygon list of restriction zones around airport runways.

The source data is lentokentat.json (airports) which contains array of airports, their IDs, center point and width and endpoints of each runway. The coordinates are in WGS84 and width is in meters.

The script generates circles of given diameter (e.g. 1 km or 3 km) at multiple points along the length of the runway(s) and then combines all the circles to one polygon.

The following example shows two restriction zones for EFHK built using the script. The inner one is at 1 km from the runways and the second one is at 3 km from the runways. The zones are single polygon each.

The included source data is hand crafted from publicly available AIS AIP (Fi), AIS AIP (En) data, textpage of each airport, e.g. Helsinki-Vantaa EFHK.

AIS publishes supplements on their webpage in pdf format. The supplements temporarily change the contents of the AIP.

Some pdf files of the supplements have embedded xml file(s), which contain e.g. temporary restriction zone definitions. These xml files are easily parsed and the restriction zone polygons together with their validity time can be parsed.

This tool periodically checks the AIS SUP webpage for new pdf files, downloads them and parses the included xml file(s). It also periodically checks which zones are valid (by their timestamp) and writes out a geojson file which includes all valid restriction zones.

The tool has multiple options for configuring the output. The basic command line is: python ais_sup.py --file=sup.geojson with following options possible

 --file         output file name, default --file=sup.geojson
 --types        feature types to export, e.g. --file=RD (restricted, danger), R (only restriction zones), D (only danger zoner)
 --fetch        fetch new sup files interval, hours, eg. --fetch=24
 --update       update the geojson file interval, hours, e.g. --update=1
 --no-active    do no create features for currently active regions
 --no-passed    do no create features for passed regions
 --no-pending   do no create features for pending (valid in future) regions
 -v, --verbose, verbose output, add multiple for more info

By default the tool outputs all restriction zones regardless of whether they are currently active, passed or in the future. The AIS wepage is fetched every 12 hours and the geojson is updated every 1 hour.

lentokentat.json is the source data used to generate restriction zones around airports, see airports.py. The file is a dictionary containing one key airports which is an array of airports. All the airports have following structure:

{
  "id":"EFPO",
  "name":"Pori",
  "date":"24.5.2018",
  "updated":"12.8.2018",
  "center":[21.7977777778,61.4613888889],
  "runways":{
    "12/30":{"width":60,"length":2351,"end1":[21.7813444444,61.4681138889],"end2":[21.8171194444,61.455775]},
    "17/35":{"width":30,"length":801,"end1":[21.7984777778,61.4639777778],"end2":[21.8000777778,61.4568305556]}}
}

where idis the identification of the airport, name is the human readable name, date is the date the information was last checked (from the source data at AIS), updated is the date when the pdf file in the AIS webpage was updated, center contains array of longitude, latitude in WGS84, and runwaysis a dictionary of all the runways of the airport.

The runways dictionary has the runway name as the key (e.g. 12/30 which is the heading of the runway, 120 degrees or 300 degrees depending on the direction). For each runway following variables are given: width is the runway width in meters, length is the runway length in meters, end1 is longitude, latitude of one end of the runway and end2is the longitude, latitude of the other end.