Microwave Staring Correlated Imaging Based on Time-Division Observation and Digital Waveform Synthesis

Abstract

As a newly proposed high resolution computational imaging technique, Microwave Staring Correlated Imaging (MSCI) requires elaborate design of the temporal-spatial stochastic radiation fields (TSSRF). Conventional implementation of MSCI radiation source consists of multiple transmitters configuration and simultaneous emitting scheme, which remains underutilization of the available design resources. In this paper, a time-division MSCI (TD-MSCI) method is proposed to virtually generate the TSSRF and make further use of the available design resources. Different from convention simultaneously transmitting based MSCI, the detection scheme in TD-MSCI is achieved by alternately transmitting of each transmitter, rather than simultaneous transmission of multiple transmitters. Echo enhancement is conducted to improve the SNR level of the echo waveform and to resolve the power coastdown caused by single transmitting scheme. Unused combinations of existing resources are digitally synthesized in computer rather than taking extra observations in actual physical environment. After the processing of time division observation, echo enhancement and digital waveform synthesis, extending TSSRF with better stochastic characteristics are generated, and improved imaging performance is obtained. Numerical imaging experiments and preliminary real-world imaging experiment verify the effectiveness of the proposed TD-MSCI, demonstrating that the proposed method increases the flexibility in radiation source design and decreases the detection costs.

Microwave Staring Correlated Imaging Method Based on Steady Radiation Fields Sequence

“…P is an arbitrary point in the 2-D imaging region S. r 0 , r n , and r are the position vectors of the receiver, the n-th transmitting antenna D n , and the arbitrary point P, respectively. The imaging system generates M pulses by simultaneous transmission of all the N transmitters [33]. The excitation signal to the n-th transmitting antenna has the following form as multiple pulse signal, as shown in Figure 2b.…”

“…A single receiver is utilized in the radar system. To generate the needed steady radiation fields sequence, the system architecture illustrated in Figure 11 is approximately implemented by a time-decision scheme and digital waveform schedule [33]. A 2-D high-precision scanning antenna mount is used as the platform of a single transmitting platform.…”

“…The sweeping frequency step of the Network Analyzer is 1 MHz, thus, 1000 different frequencies are used at each transmitting position. As demonstrated in [33], MSCI with multiple transmitters and simultaneous emitting scheme can be achieved by time-division scheme, with the predesigned radiation fields implemented by the digital waveform synthesis procedure. Therefore, the time-division scheme is adopted in the real-world imaging experiment of the proposed SRFS-MSCI method.…”