B2-Spline Interpolation Technique for Overset Grid Generation and Finite-Difference Time-Domain Method

• Main Authors: Bong, S. Wee, Shafrida, binti Sahrani @ Shahran, Kismet, anak Hong Ping
• Format: E-Article
• Language: English
• Published: EMW Publishing 2018
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://ir.unimas.my/id/eprint/21492/1/B2-Spline%20interpolation%20technique%20for%20overset%20%28abstrak%29.pdf; http://ir.unimas.my/id/eprint/21492/; http://www.jpier.org/PIERC/pierc86/14.18052404.pdf

—In this paper, B2-spline interpolation technique for Overset Grid Generation and FiniteDifference Time-Domain (OGG-FDTD) method was developed. B2-spline or biquadratic spline interpolation offers better accuracy than bilinear interpolation. Two-dimensional (2D) numerical simulations were carried out for electromagnetic (EM) field analysis to measure the scattered fields for an unknown object in free space and dielectric medium. In this work, two antennas were utilised as transmitter and receiver sequentially to transmit microwave pulses and collect the scattered fields for an unknown object in OGG-FDTD lattice. In order to analyse the stability and efficiency of the proposed method, the scattered fields for the unknown object were investigated with error analysis. The results showed that the OGG-FDTD method with B2-spline interpolation gave lower relative error than bilinear interpolation with 0.0009% of difference in free space, 0.0033% of difference in Case A dielectric medium, 0.236% of difference in Case B dielectric medium, and 0.003% of difference in Case C dielectric medium. Besides, the Mean Square Error (MSE) for the OGG-FDTD method with B2-spline interpolation was also lower than the bilinear interpolation. Hence, it proves that the OGG-FDTD method with B2-spline interpolation has the ability to measure the scattered fields around an unknown object accurately. For future work, the proposed method can be applied to inverse scattering to detect and reconstruct buried objects with arbitrary shapes in a complex media.