ISAR Imaging for Low-Earth-Orbit Target Based on Coherent Integrated Smoothed Generalized Cubic Phase Function

2020 ◽  
Vol 58 (2) ◽  
pp. 1205-1220 ◽  
Author(s):  
Yuhan Du ◽  
Yicheng Jiang ◽  
Yong Wang ◽  
Wei Zhou ◽  
Zitao Liu
Keyword(s):  
Phase Function ◽  
Low Earth Orbit ◽  
Cubic Phase ◽  
Earth Orbit ◽  
Isar Imaging ◽  
Cubic Phase Function

scholarly journals Quadratic Frequency Modulation Signals Parameter Estimation Based on Product High Order Ambiguity Function-Modified Integrated Cubic Phase Function

Information ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 140 ◽  
Author(s):  
Lei Zhu
Keyword(s):  
Phase Function ◽  
Imaging System ◽  
Ambiguity Function ◽  
High Order ◽  
Cubic Phase ◽  
Chirp Rate ◽  
Cross Term ◽  
Isar Imaging ◽  
Identifiability Problem ◽  
Cubic Phase Function

In inverse synthetic aperture radar (ISAR) imaging system for targets with complex motion, such as ships fluctuating with oceanic waves and high maneuvering airplanes, the multi-component quadratic frequency modulation (QFM) signals are more suitable model for azimuth echo signals. The quadratic chirp rate (QCR) and chirp rate (CR) cause the ISAR imaging defocus. Thus, it is important to estimate QCR and CR of multi-component QFM signals in ISAR imaging system. The conventional QFM signal parameter estimation algorithms suffer from the cross-term problem. To solve this problem, this paper proposes the product high order ambiguity function-modified integrated cubic phase function (PHAF-MICPF). The PHAF-MICPF employs phase differentiation operation with multi-scale factors and modified coherently integrated cubic phase function (MICPF) to transform the multi-component QFM signals into the time-quadratic chirp rate (T-QCR) domains. The cross-term suppression ability of the PHAF-MICPF is improved by multiplying different T-QCR domains that are related to different scale factors. Besides, the multiplication operation can improve the anti-noise performance and solve the identifiability problem. Compared with high order ambiguity function-integrated cubic phase function (HAF-ICPF), the simulation results verify that the PHAF-MICPF acquires better cross-term suppression ability, better anti-noise performance and solves the identifiability problem.

scholarly journals An Inverse Synthetic Aperture Ladar Imaging Algorithm of Maneuvering Target Based on Integral Cubic Phase Function-Fractional Fourier Transform

Electronics ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 148 ◽  
Author(s):  
Yakun Lv ◽  
Yanhong Wu ◽  
Hongyan Wang ◽  
Lei Qiu ◽  
Jiawei Jiang ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Phase Function ◽  
Fractional Fourier Transform ◽  
Doppler Frequency ◽  
Synthetic Aperture ◽  
Cubic Phase ◽  
Echo Signal ◽  
Imaging Algorithm ◽  
Maneuvering Target ◽  
Cubic Phase Function

When imaging maneuvering targets with inverse synthetic aperture ladar (ISAL), dispersion and Doppler frequency time-variation exist in the range and cross-range echo signal, respectively. To solve this problem, an ISAL imaging algorithm based on integral cubic phase function-fractional Fourier transform (ICPF-FRFT) is proposed in this paper. The accurate ISAL echo signal model is established for a space maneuvering target that quickly approximates the uniform acceleration motion. On this basis, the chirp rate of the echo signal is quickly estimated by using the ICPF algorithm, which uses the non-uniform fast Fourier transform (NUFFT) method for fast calculations. At the best rotation angle, the range compression is realized by FRFT and the range dispersion is eliminated. After motion compensation, separation imaging of strong and weak scattering points is realized by using ICPF-FRFT and CLEAN technique and the azimuth defocusing problem is solved. The effectiveness of the proposed method is verified by a simulation experiment of an aircraft scattering point model and real data.

scholarly journals Group Delay Dispersion Measurement From a Spectral Interferogram Based on the Cubic Phase Function

2014 ◽  
Vol 6 (6) ◽  
pp. 1-9 ◽  
Author(s):  
Chongxiang Zeng ◽  
Hongxia Zhang ◽  
Dagong Jia ◽  
Tiegen Liu ◽  
Yimo Zhang
Keyword(s):  
Phase Function ◽  
Group Delay ◽  
Group Delay Dispersion ◽  
Cubic Phase ◽  
Dispersion Measurement ◽  
Cubic Phase Function

Parameter Estimation of Multicomponent Cubic Phase Signals

2013 ◽  
Vol 380-384 ◽  
pp. 3726-3729
Author(s):  
Peng Fei Tang ◽  
Bin Yuan ◽  
Qian Qiang Lin ◽  
Zeng Ping Chen
Keyword(s):  
Parameter Estimation ◽  
Numerical Simulations ◽  
Phase Function ◽  
Cubic Phase ◽  
Chirp Rate ◽  
Signal Component ◽  
Phase Signal ◽  
Cubic Phase Function

This paper presents an algorithm for estimating the parameters of multicomponent cubic phase signals. This algorithm combines the product generalized cubic phase function (PGCPF) and the product cubic phase function (PCPF) which are used to estimate the cubic phase coefficient and chirp rate of the cubic phase signal, respectively. This algorithm starts by estimating the parameters of the signal component with the strongest amplitude. Then removing the signal component whose parameters have been estimated, it proceeds to estimate the next signal component, and so on, until all of the signal components have been estimated. Numerical simulations are carried out to validate the performance of the proposed algorithm.

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