arXiv:2604.02827v3 Announce Type: replace Abstract: In-flight outdoor approximation of full 3D Radiation Patterns (RPs) in non-holonomic multi-rotor Uncrewed Aerial Vehicles (UAVs) enables efficient communication-aware robotic missions. Our method identifies the Spherical Harmonics series coefficients, decoupling the observed signal power gains into respective RPs. The proposed calibration trajectory provides training and testing samples of signal strength at an obstacle-free altitude. Simulation verifies the proposed novel approximation of the RPs, and real-world validation achieves an RMS prediction error under 5dB.