Abstract
In this paper, a fast three-dimensional (3-D) frequency scaling algorithm (FSA) with large depth of focus is presented for near-field planar millimeter-wave (MMW) holographic imaging. Considering the cross-range range coupling term which is neglected in the conventional range migration algorithm (RMA), we propose an algorithm performing the range cell migration correction for de-chirped signals without interpolation by using a 3-D frequency scaling operation. First, to deal with the cross-range range coupling term, a 3-D frequency scaling operator is derived to eliminate the space variation of range cell migration. Then, a range migration correction factor is performed to compensate for the residual range cell migration. Finally, the imaging results are obtained by matched filtering in the cross-range direction. Compared with the conventional RMA, the proposed algorithm is comparable in accuracy but more efficient by using only chirp multiplications and fast Fourier transforms (FFTs). The algorithm has been tested with satisfying results by both simulation and experiment.
Highlights
The millimeter-wave (MMW) imaging technique holds large potential in the application of security inspection for its unique electromagnetic properties [1,2]
We present a fast three-dimensional (3-D) frequency scaling algorithm with large depth of focus for near-field planar millimeter-wave holographic imaging
The 3-D frequency scaling algorithm (FSA) takes the cross-range range coupling term, which is neglected in conventional range migration algorithm (RMA), into consideration and performs the range cell migration correction for de-chirped signal without interpolation by using a 3-D frequency scaling operation
Summary
The millimeter-wave (MMW) imaging technique holds large potential in the application of security inspection for its unique electromagnetic properties [1,2]. Most near-field wideband planar MMW holographic imaging systems adopted RMA as the imaging algorithm, and a series of improvements have been made based on RMA such as replacing interpolation and fast Fourier transform (FFT) by non-uniform FFT [14], compensating for the antenna position error which is caused by mechanical scanning of linear antenna array [15], and so on. We present a fast three-dimensional (3-D) frequency scaling algorithm with large depth of focus for near-field planar millimeter-wave holographic imaging. The near-field planar millimeter-wave holographic imaging scene and the proposed fast three-dimensional (3-D) frequency scaling algorithm with large depth of focus is described.
Published Version (Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have