3D Body Scanning Measurement System Associated with RF Imaging, Zero-padding and Parallel Processing

Abstract

Abstract This work presents a novel signal processing method for high-speed 3D body measurements using millimeter waves with a general processing unit (GPU) and zero-padding fast Fourier transform (ZPFFT). The proposed measurement system consists of a radio-frequency (RF) antenna array for a penetrable measurement, a high-speed analog-to-digital converter (ADC) for significant data acquisition, and a general processing unit for fast signal processing. The RF waves of the transmitter and the receiver are converted to real and imaginary signals that are sampled by a high-speed ADC and synchronized with the kinematic positions of the scanner. Because the distance between the surface and the antenna is related to the peak frequency of the conjugate signals, a fast Fourier transform (FFT) is applied to the signal processing after the sampling. The sampling time is finite owing to a short scanning time, and the physical resolution needs to be increased; further, zero-padding is applied to interpolate the spectra of the sampled signals to consider a 1/m floating point frequency. The GPU and parallel algorithm are applied to accelerate the speed of the ZPFFT because of the large number of additional mathematical operations of the ZPFFT. 3D body images are finally obtained by spectrograms that are the arrangement of the ZPFFT in a 3D space.