public List<airport> readAirports(String airportFilename)
{
///////////////////////////////////////////////////////////////////////////////////////
//read the List of airports from a file
///////////////////////////////////////////////////////////////////////////////////////
List<airport> apts = new List<airport>();
StreamReader sr = new StreamReader(airportFilename);
while (!sr.EndOfStream)
{
String []values = sr.ReadLine().Split(new char[]{':'});
airport apt = new airport();
apt.name = values[0];
apt.City = values[1];
apt.ICAO_designator = values[2];
try
{
apt.lat = Convert.ToDouble(values[3]);
apt.lon = Convert.ToDouble(values[4]);
apt.altitude = Convert.ToDouble(values[5]);
apt.easting = Convert.ToDouble(values[6]);
apt.northing = Convert.ToDouble(values[7]);
apt.distanceToPolyCenterMi = Convert.ToDouble(values[8]);
}
catch
{
System.Windows.Forms.MessageBox.Show("could not convert airport info");
}
apts.Add(apt);
}
return apts;
}
public List<airport> airportsWitin50kmRadius(double latDeg, double lonDeg, double latDegPT, double lonDegPT)
{
///////////////////////////////////////////////////////////////////////////////////////////////
//this procedure uses the Places API to get all airports within 50km of a lat/lon point
//this must be called multiple times to get airports near the client polygon
///////////////////////////////////////////////////////////////////////////////////////////////
List<airport> airports = new List<airport>(); //returned list of airports
airport apt = new airport();
apt.City = "unknown";
apt.distanceToPolyCenterMi = 0.0;
apt.ICAO_designator = "unknown";
apt.name = "unknown";
apt.lat = 0.0;
apt.lon = 0.0;
apt.altitude = 0.0;
double Northing = 0.0, Easting = 0.0;
utm.LLtoUTM(latDegPT * Deg2Rad, lonDegPT * Deg2Rad, ref Northing, ref Easting, ref UTMZone, false);
String ss = uriPreamble + latDeg.ToString() + "," + lonDeg.ToString() + uriEndString;
//below commented code gets the Places response in a local xml so you can view it.
//WebClient ww = new WebClient();
//Uri uri = new Uri(ss);
//String downloadedData = ww.DownloadString(uri); //perform the web download -- blocking call
//the below call reads the URL response directly into a xml text reader for processing
XmlTextReader textReader = new XmlTextReader(ss);
//assume the Google Places API response has name, vicinity (city), lat, lng in that order.
while (textReader.Read())
{
textReader.MoveToElement();
String m = textReader.Value;
if (textReader.IsStartElement() && textReader.Name == "name") //first
{
textReader.Read();
//must replace any "&" else kml will fail
apt.name = ((String)textReader.Value).Replace(Convert.ToChar("&"), Convert.ToChar("A"));
//Constants.Log(" airportName " + apt.name);
}
else if (textReader.IsStartElement() && textReader.Name == "vicinity") //second
{
textReader.Read();
apt.City = ((String)textReader.Value).Replace(Convert.ToChar("&"), Convert.ToChar("A"));
}
else if (textReader.IsStartElement() && textReader.Name == "lat") //third
{
textReader.Read();
apt.lat = Convert.ToDouble(textReader.Value);
}
else if (textReader.IsStartElement() && textReader.Name == "lng") //last -- when here have a complete set for one airport
{
textReader.Read();
apt.lon = Convert.ToDouble(textReader.Value); //have filled in name, City, lat above
//the airport structure also has distance from the poly center --- compute this below
double aptNorthing = 0.0, aptEasting = 0.0;
//get the UTM for this airport location
utm.LLtoUTM(apt.lat * Deg2Rad, apt.lon * Deg2Rad, ref aptNorthing, ref aptEasting, ref UTMZone, true);
//compute the distance from mean poly center computed eleswhere
double dist2 = (Northing - aptNorthing) * (Northing - aptNorthing) + (Easting - aptEasting) * (Easting - aptEasting);
double distMeters = Math.Sqrt(dist2);
//convert to miles
apt.distanceToPolyCenterMi = distMeters / .3048 / 5280.0;
apt.northing = aptNorthing;
apt.easting = aptEasting;
//add this airport to the list to return
airports.Add(apt);
}
}
return airports;
}
