Dynamics of Aircraft Flight

8Processing of Trajectography Information

Here we show, for an aircraft with aerodynamic wings and with the aerodynamics being defined in aircraft axes, that it is possible to verify, using the trajectory and the information obtained from telemetry, the performance and some major aerodynamic parameters specific to the aircraft studied.

8.1. Telemeasured parameters

The elimination of outliers must be undertaken with the raw coordinates (x_c,y_c,z_c) or z_geoid.

This operation should be undertaken seperately, because it gives us an idea of the quality of the trajectography.

8.2. Smoothing, first derivation and second derivation

For processing from the trajectography information, it is preferable to use polynomial smoothing with first derivatives and second derivatives. This processing will be carried out with the coordinates (x_c, y_c, z_c), after possible realignment (Δx_c, Δy_c, Δz_c) with respect to the origin of the trihedron.

If we have the value z_geoid, we can take:

We then obtain:

• – x_c, y_c, z_c: smoothed coordinates;
• – ẋ_c, ẏ_c, ż_c: smoothed speeds;
• – ẍ_c, ӱ_c, _c: smoothed acceleration.

8.3. Performance calculation

8.3.1. Change of coordinates to move from the trihedron (O, X_c, Y_c, Z_c) to the trihedron (O, X₀, Y₀, Z₀)

(O, X₀, Y₀, Z₀) is the reference trihedron used for the calculation. ...