# Converting local XYZ to geographic coordinates

I am working with a computer program called PEP for Windows by Airbus, which is able to calculate exact flight paths of an aircraft, based on many inputs like weight, temperature, wind, etc. The program seems to work with geometrical coordinates, as its output is giving displacement to the east (x) and north (y) in meters, including altitude as z in ft:

0.000 0.000 0.000

0.051 -0.140 0.001

0.232 -0.636 0.003

0.616 -1.692 0.008

1.309 -3.595 0.018

2.423 -6.657 0.033

4.057 -11.147 0.054

6.280 -17.254 0.084

9.124 -25.069 0.123

12.597 -34.610 0.169

16.695 -45.869 0.224

The above example represents an acceleration at an airport during the first 10 seconds of the takeoff roll, where you can see the aircraft moves in southeastern direction on an upslope runway (slope data was given as an input parameter, but as soon as the aircraft lifts off, the z parameter shows either the height above the starting point or altitude above sea level, to be chosen by the user).

My objective is to be able to import this trajectory into Google Earth Pro in order to visualize the flight path, in combination with the elevation profile option to see the terrain clearance of the aircraft at each point of the flight (in the absence of knowing better software to see this). I believe I need to use a program like QGIS to convert the coordinates into Lat Long, right? Could anybody explain me which steps to follow in order to achieve my goal?

• if you knew the first lat/lng coordinate for the start of the flight (guessing an airport) you can shift your 0,0 coordinates using georeferencing (qgis would do this) – Mapperz Jun 4 '15 at 15:40
• The solution to a related question I posted at gis.stackexchange.com/a/34534 contains everything you need to know to convert 3D points to geodetic coordinates to high precision. A search for ellipsoid coordinate will turn up almost a hundred related answers. – whuber Jun 4 '15 at 16:39
• @Mapperz: starting point indeed is an airport, a runway threshold to be exact. I'm gonna invest time in sorting out if my problem could be solved using georeferencing, by first finding out how it works:) Thank you for your reply! – Edwin Jun 6 '15 at 16:17
• @Martin F: The coordinates (or points, cause I don't know if you can call them coordinates already..) come from a program which calculates the movement of an aircraft. I don't know the reference system the program uses (I'm only vagely familiar with chart projections), but I guess it doesn't take into account the curvature of the Earth, simply the track it's flying through the air based on the atmospheric conditions I introduce as input.The question is, how can I import this path I get into google earth? I presume I'll have to convert it into coordinates based on WGS84, right? – Edwin Jun 6 '15 at 16:26
• @Martin F: The commas are decimal points indeed, but the units are meters, as the program is supposed to make accurate calculations. – Edwin Jun 6 '15 at 16:29