RESUMO
This paper proposes the implementation of and experimentation with GPR for real-time automatic detection of buried IEDs. GPR, consisting of hardware and software, was implemented. A UWB antenna was designed and implemented, particularly for the operation of the GPR. The experiments were conducted in order to demonstrate the real-time automatic detection of buried IEDs using GPR with an R-CNN algorithm. In the experiments, the GPR was mounted on a pickup truck and a maintenance train in order to find the IEDs buried under a road and a railway, respectively. B-scan images were collected using the implemented GPR. R-CNN-based detection for the hyperbolic pattern, which indicates the buried IED, was performed along with pre-processing, for example, using zero offset removal, and background removal and filtering. Experimental results in terms of detecting the hyperbolic pattern in B-scan images were shown and verified that the proposed GPR system is superior to the conventional one using region analysis processing-based detection. Results also showed that pre-processing is required in order to improve and/or clean the hyperbolic pattern before detection. The GPR can automatically detect IEDs buried under roads and railways in real time by detecting the hyperbolic pattern appearing in the collected B-scan image.
Assuntos
Radar , Armas , Pesquisa Empírica , Projetos de Pesquisa , AlgoritmosRESUMO
In light of the growth in demand for multiband antennas for medical applications, this research proposes a MICS/ISM meander-line microstrip antenna encapsulated in an oblong-shaped pod for use in diagnoses of the gastrointestinal tract. The proposed antenna is operable in the Medical Implant Communication System (MICS) and the Industrial, Scientific and Medical (ISM) bands. The antenna structure consists of a meander-line radiating patch, a flipped-L defected ground plane, and a loading resistor for antenna miniaturization. The MICS/ISM microstrip antenna encapsulated in an oblong-shaped pod was simulated in various lossy-material environments. In addition, the specific absorption rate (SAR) was calculated and compared against the IEEE C95.1 standard. For verification, an antenna prototype was fabricated and experiments carried out in equivalent liquid mixtures, the dielectric constants of which resembled human tissue. The measured impedance bandwidths (|S11| ≤ -10 dB) for the MICS and ISM bands were 398-407 MHz and 2.41-2.48 GHz. The measured antenna gains were -38 dBi and -13 dBi, with a quasi-omnidirectional radiation pattern. The measured SAR was substantially below the maximum safety limits. As a result, the described MICS/ISM microstrip antenna encapsulated in an oblong-shaped pod can be used for real-time gastrointestinal tract diagnosis. The novelty of this work lies in the use of a meander-line microstrip, flipped-L defected ground plane, and loading resistor to miniaturize the antenna and realize the MICS and ISM bands.