Altitude

Question

I'm trying to work with the altitude that is returned from the system with an airborne entity.

The spec states that the altitude can be retrieved as either "Altitude above the surface" or "Altitude of aircraft". The surface is then given its own separate altitude which is described as "Altitude of surface". So in theory I can work with this... however I"m still not given what the altitude is in reference to?

I need to convert to altitude with reference to height above the standard WGS84 spheriod - so can you help here at all?


While I'm on the topic - the system jumps from feet to meters in the "PLANE ALT ABOVE GROUND" and "GROUND ALTITUDE" is this intentional?

Answer 1

Hi RBG79,

Our Altitude of Aircraft (also known as Altitude MSL - altitude above mean sea level, which should be roughly equiv to height above the WGS84 spheroid, which is what our round earth model is based on).  The other altitude would be referred to as Altitude AGL - Above Ground Level, which would be your vehicles height above the terrain below.  As to units, you can request any length/distance based SimVar in either Feet or Meters, in general, the UNITS column in the SDK docs either lists the "default" units the var is stored in, or an example unit to denote the type of unit (so length vs speed vs angular rotation vs etc) - in general, you can request any SimVar in whatever units you would like, as long as it makes sense for the type of unit, and is one of the official unit string values described at the bottom of the Variable list in the SDK.

Tim

---

http://beatlesblog.spaces.live.com/