title: ambiguity over information returned by GoogleMaps Elevation Api
body: <p>I want to ask whether the value returned by google maps' elevation api is the height of the ground-surface from the sea level? So, if there is a foot over bridge or an elevated road would the api return the elevation of the ground or of the structure built on the ground(elevated road in this case)? </p>
  
  <p>How and where may I get information related to elevations of such man made structures(bridges) which are not on ground level, rather at an elevation? </p>