Google Map API alternative for your GPS Tracking website reverse geocoding

Google Map API for reverse Geo-coding of Address information is not free now. You have some limitations for daily usage. being in GPS tracking world, we will need Reverse Geo-coding for all the vehicles we track.

In this Blog i will discuss some alternatives to Google maps for reverse Geo-coding.

ESRI REST API:


ESRI has a rest api using which you can reverse Geo-coding your Latitude and Longitude into an Address. The REST url returns a Json string with required Address information.

For Example i have below information of CharMinar area (an Historical Monument in Hyderbad,India)

Country	India
Latitude	17.361431
Longitude	78.474533
DMS Lat	17° 21' 41.1516'' N
DMS Long	78° 28' 28.3188'' E

The REST API to get reverse geo coded address

http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/reverseGeocode?location=78.474533%2C17.361431&langCode=fr&outSR=&forStorage=false&f=pjson


The REST response in json as below

{
 "address": {
  "Match_addr": "Kamla Maternity Nursing Home and Ultrasound Centre",
  "LongLabel": "Kamla Maternity Nursing Home and Ultrasound Centre, Charminar Chowk, Chandulal Baradari, Hyderabad, Telangana, 500002, IND",
  "ShortLabel": "Kamla Maternity Nursing Home and Ultrasound Centre",
  "Addr_type": "POI",
  "Type": "Medical Clinic",
  "PlaceName": "Kamla Maternity Nursing Home and Ultrasound Centre",
  "AddNum": "",
  "Address": "Charminar Chowk",
  "Block": "",
  "Sector": "",
  "Neighborhood": "",
  "District": "Chandulal Baradari",
  "City": "Hyderabad",
  "MetroArea": "Greater Hyderabad",
  "Subregion": "Hyderabad",
  "Region": "Telangana",
  "Territory": "",
  "Postal": "500002",
  "PostalExt": "",
  "CountryCode": "IND"
 },
 "location": {
  "x": 78.474430000000041,
  "y": 17.361410000000035,
  "spatialReference": {
   "wkid": 4326,
   "latestWkid": 4326
  }
 }
}

Summary: using any json de-serializer , you can grab the required information to store the same to your database for later use. the below code snippet is an example from c# code.

C# code------------------------

// create a function to GET the json string by consuming the ESRI Rest

    string GET(string url)
    {
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        try
        {
            WebResponse response = request.GetResponse();
            using (Stream responseStream = response.GetResponseStream())
            {
                StreamReader reader = new StreamReader(responseStream, System.Text.Encoding.UTF8);
                return reader.ReadToEnd();
            }
        }
        catch (WebException ex)
        {
            WebResponse errorResponse = ex.Response;
            using (Stream responseStream = errorResponse.GetResponseStream())
            {
                StreamReader reader = new StreamReader(responseStream, System.Text.Encoding.GetEncoding("utf-8"));
                String errorText = reader.ReadToEnd();
                // log errorText
            }
            throw;
        }
    }

// Call above function as below

String ucode = GET("http://geocode.arcgis.com/arcgis/rest/services/World/GeocodeServer/reverseGeocode?location=" + LONGITUDE + "%2C" + LATITUDE + "langCode=fr&outSR=&forStorage=false&f=pjson");

// de-serialization  of json, i have used Newtonsoft json.net for the purpose

var json = ucode;

dynamic results = Newtonsoft.Json.JsonConvert.DeserializeObject<dynamic>(json);
                    

String id = results.address.LongLabel;  // i need only longlabel, you can grab any 

I will post another way of reverse-geocoding in my next blog..feel free to ask any questions related to the above at sree@itoolz.in