To accurately localize unmanned aerial vehicles (UAVs) is one of the key issues to deal with the security threats caused by UAVs. Thus, this article proposes a UAV localization scheme that utilizes the area grid quantization and transmit power statistical calibration techniques, in which the location and transmit power of the UAV are unknown. Firstly, the adaptive discrete particle swarm optimization (ADPSO) algorithm is used to find the global optimal solution to the localization problem. A grid quantization method is proposed to discretize the value space of the traditional PSO algorithm to reduce the estimated localization time. An adaptive factor is also introduced to adjust the value of power for each iteration in the discrete particle swarm optimization (DPSO) algorithm in order to find the global optimal solution efficiently. Secondly, the fixed transmit power range is adopted to calibrate the estimated value of transmit power and the corresponding location. The prototype system comprises four anchor nodes based on a universal software radio peripheral radio frequency (USRP RF). Finally, field experiments are carried out to demonstrate the effectiveness of the proposed localization scheme.

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A silica aerogel (SA)/poly(methyl methacrylate) (PMMA) hybrid composite with a non-covalent interaction phase interface was prepared by introducing γ-aminopropyltriethoxysilane and acrylamide. The effects of the non-covalent interaction phase interface on the performance of SA/PMMA hybrid composites have been investigated by performing scanning electron microscopy, energy-dispersive X-ray spectrometer, Fourier transform infrared spectrometer, nitrogen gas (N2) adsorption–desorption, thermogravimetric analysis, gel permeation chromatograph and mechanical bending strength test. The results indicated that an SA/PMMA hybrid composite with a non-covalent interaction phase interface and a nanoporous structure was obtained. The strong interface bond strength of the non-covalent interaction phase interface between SA phase and polymer phase facilitated the coupling effect for phonon transmission, which could improve the thermal stability and the thermal conductivity of composites. The strong interface bond strength of the non-covalent interaction phase interface also restricted the movement of the molecular chains of the polymer, which could improve the mechanical properties of composites.