GeoJSON Service Help

NAV Site

Location: /cgi-bin/json/NavSiteJSON.php

This script will create GeoJSON output using data from the NASR database. This will extract a list of Navigation Aids from the database. Here is sample output:

{ "type": "FeatureCollection",
    "features": [
    { "type": "Feature",
      "id": "66",
      "properties": {
          "data": "NAVAIDS",
          "id": "DCU",
          "type": "VOR/DME",
          "name": "DECATUR",
          "state": "AL",
          "country": "US",
          "elev": "182",
          "freq": "112.80",
          "mag_dev": "01W"
      },
      "geometry": {
          "type": "Point",
          "coordinates": [-86.939,34.648]
      } 
    },
    { "type": "Feature",
        "id": "74",
        "properties": {
            "data": "NAVAIDS",
            "id": "RQZ",
            "type": "VORTAC",
            "name": "ROCKET",
            "state": "AL",
            "country": "US",
            "elev": "369",
            "freq": "112.20",
            "mag_dev": "02E"
        },
        "geometry": {
            "type": "Point",
            "coordinates": [-86.634,34.797]
        } 
    },
    { "type": "Feature",
        "id": "79",
        "properties": {
...

The properties output from the script are:

  • id - Navigation identifier
  • type - NavAid type: VORTAC, VOR/DME, VOR, NDB/DME, NDB
  • name - The name for the site
  • state - State within country/region
  • country - Country
  • elev - Elevation of site in meters
  • freq - Radio frequency of navigational aid
  • mag_dev - Magnetic variation/deviation from true north

The script can be passed parameters via command line or through CGI REQUEST. The parameters to the script include:

  • bbox=minlon,minlat,maxlon,maxlat - This is the bounding box for area of interest. This limits the stations output in GeoJSON to those within that lat/lon range. The default is -130,20,-60,60.
  • filter=prior - This tells the script to use a priority scheme to filter stations on a priority scheme. It will base what priority to use on the size of the bounding box. The priority is 3 for VORTAC, VOR/DME, 4 for NDB/DME, VOR, and 5 for NDB. The default is to only return nav aids with a priority of 3 or lower.
  • priority=# - This sets the default priority. The default is 3.
  • jsonp=callback - This sets the callback function to be used in a JSONP call. This is just when the script is called on another server. The default is null which outputs straight JSON.