Getting Altitude(height from sea level) of my location in iphone SDK

Question

I am trying to get Altitude of my location in my application. But every time I try altitude property of CLLocation object I am getting 0.00

Answer 1

See Android - Get Altitude By Longitude and Latitude? there is an Android solution but it is easily adaptable to iOS.

The answer is to use the USGS Elevation Query Web Service

From the top answer there, basically you just send an HTML Web request to:

http://gisdata.usgs.gov/xmlwebservices2/elevation_service.asmx/getElevation?X_Value=" + 
             String.valueOf(longitude)   + 
             "&Y_Value=" + String.valueOf(latitude)             
             + "&Elevation_Units=METERS&Source_Layer=-1&Elevation_Only=true"; 

Then you can parse out the response text from between the ... tags

Edit: It looks like you might be trying to get elevation outside the United States.

Google Maps API does provide an Elevation service and documentation at https://developers.google.com/maps/documentation/javascript/elevation