[Orekit Users] Inertial to Topocentric coordinate transformation

[Petrus Hyvönen <petrus.hyvonen@gmail.com>]

Hi,

This may again be a FAQ, but..

I'm getting very strange elevations from stations to inertial objects. I follow kind of the examples with:

(note python-code, so view it as pseudo-code.. :)

ae = 6378137.0 # // equatorial radius in meter (WGS84)

f = 1.0 / 298.257223563 #; // flattening (WGS84)

ITRF2005 = FramesFactory.getITRF2005() #; // terrestrial frame at an arbitrary date

earth = OneAxisEllipsoid(ae, f, ITRF2005)

# Station

longitude = radians( 21.063)

latitude = radians(67.878)

altitude = 341.0

station1 = GeodeticPoint(latitude, longitude, altitude)

sta1Frame = TopocentricFrame(earth, station1, "Station")

Then I setup the propagation (inertial position verified with STK), propagate and:

el_tmp = sta1Frame.getElevation(pv.getPosition(),inertialFrame, extrapDate)*180.0/pi

The result seems to be much too low with no passes above horizon and a mean about -42 degrees. Somehow my frames must be mixed up. Any comments appriciated.

/Petrus