Reduced Complexity multi-frequency imaging using active aperture synthesis.

Active imaging utilizes an may of transmitting elements to illuminate a Scene and an array of receiving elements to capture and process the reflections. The narrowband coarray defmition provides a convenient framework for understanding active imaging, and designing schemes to reduce the number of transmining and receiving elements required. Widehand signals have been used for active aperture synthetic imaging to obtain range resolution, as well as to improve angular resolution The step- frequency method achieves the effect of short duration pulses through frequency synthesis, and the coarray idea can be applied in this situation also. In this paper, we investigate approaches to reduce the signal processing time and hardware complexity of multkfrequency imging schemes, while still maintaining a reasonable image quality. In one approach we randomly drop points in the frequencycoarray space. Another scheme uses n m w band traosmissions (groups of frequencies) fmm multiple transmitters and results in a pseudorandom placement of frequencycoarray points. Orthogonal transmission of multifrequencies allows simultaneous detection at receivers and reduces image acquisition time. Simulation results show good performance and hardware complexity and acquisition time trade-offs.

Main Author: Guo, Yi.
Other Authors: Kassam, A., Ahmad, Fauzia., Amin, Moeness.
Language: English
Published: 2004
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