Octocopter misalignments and misplacements Sample Clauses

Octocopter misalignments and misplacements. ‌ Misalignments and misplacements of the octocopter during the calibration flight have a direct impact on the transmitting antenna position and orientation changing the signal polarization at the ˆ position of the AUT. For this investigation the orientation of the transmission antenna is assumed to correspond to a dipole, which holds to a good approximation. The electric field E→t emitted from a dipole antenna with orientation Aˆt in the direction nˆ in the far-field region is proportional to E→t ∼ (nˆ × Aˆt ) × nˆ, and the amplitude is given by |E→t | = sin(α). Here, α describes the smallest angle between the transmitting antenna alignment At and the direction from the transmitting antenna to the AUT denoted as nˆ (see lower sketch of figure 2). The orientation of the transmitting antenna Aˆt is calculated by an intrinsic rotation of the initial orientation of the transmitting antenna rotating first by the yaw angle G, then by the pitch angle P and finally, by the roll angle R. The AUT sensitivity 2017 y to the emitted electric field is then calculated by the absolute value of the scalar product of the electric field and the AUT orientation Aˆr : y = |E→t · Aˆr | = sin(α) cos(β) with β describing the smallest angle between E→t and Aˆr (see lower sketch of figure 2). Finally, the correction factor JINST s of the power measured at the AUT is determined by the square of the quotient of the nominal and the real value of y. In case of the horizontal component |Hφ | the VEL is systematically shifted to larger values for all zenith angles and frequencies due to the octocopter misalignment and misplacement. The correction factor s is used to determine the horizontal VEL |Hφ |. In both meridional subcomponents the VEL becomes small at large zenith angles and strongly dependent on the antenna alignments. Therefore, in the meridional subcomponents |Hθ,hor| and |Hθ,vert| the effects of the octocopter misalignment and misplacement are included in the systematic uncertainties.