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 tr...
| Main Authors: | , , , |
|---|---|
| Format: | |
| Language: | English |
| Published: |
2004
|
| Online Access: | http://ezproxy.villanova.edu/login?url=https://digital.library.villanova.edu/Item/vudl:173591 |
| Summary: | 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. |
|---|