L, Uuml, Ming-jiu, et al. A New High Resolution Chirp Frequency Stepped ISAR Imaging Algorithm by Using Two-Dimensional Sparse Structure Information[J]. Acta Electronica Sinica, 2018, 46(12): 2905-2913.
DOI:
L, Uuml, Ming-jiu, et al. A New High Resolution Chirp Frequency Stepped ISAR Imaging Algorithm by Using Two-Dimensional Sparse Structure Information[J]. Acta Electronica Sinica, 2018, 46(12): 2905-2913. DOI: 10.3969/j.issn.0372-2112.2018.12.012.
A New High Resolution Chirp Frequency Stepped ISAR Imaging Algorithm by Using Two-Dimensional Sparse Structure Information
In order to improve the performance of the ISAR imaging method based on compressed sensing under sub-sampling and low SNR
a new high resolution ISAR imaging method for chirp frequency stepped signal is proposed
based on the unique characteristics of the stepped frequency waveform
and the two-dimensional sparse structure information of the target. The proposed method is deal with the cross range focusing first and then the range resolution. Firstly
the pulse compression is performed on the sub-pulse echo
and then based on the analysis of the sparse structure of the stepped frequency ISAR echo in cross range dimension
a distributed compressed sensing model is constructed; Secondly
the DCS-SOMP algorithm is used to reconstruct the model
then the high cross range resolution imaging in low SNR is obtained; Finally
an arbitrary sparse representation model is constructed by using the echo characteristics in range dimension. Because the proposed method
which is cross range focusing first and then the range resolution
makes full use of the target structure
it not only avoids the migration through range resolution cell effect on the cross range resolution
but also has strong anti-noise performance
high reconstruction accuracy and low sampling rate. The validity of the proposed method is verified by simulation and experimental data.