scholarly journals Precise Aperture-Dependent Motion Compensation with Frequency Domain Fast Back-Projection Algorithm

Sensors ◽  
2017 ◽  
Vol 17 (11) ◽  
pp. 2454 ◽  
Author(s):  
Man Zhang ◽  
Guanyong Wang ◽  
Lei Zhang
Keyword(s):  
Frequency Domain ◽  
Motion Compensation ◽  
Projection Algorithm ◽  
Back Projection

scholarly journals Precision Imaging of Frequency Stepped SAR with Frequency Domain Extracted HRRP and Fast Factorized Back Projection Algorithm

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Can-bin Yin ◽  
Da Ran
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Single Point ◽  
Projection Algorithm ◽  
Great Promise ◽  
Back Projection ◽  
Imaging Processing ◽  
Block Partition ◽  
Range Resolution ◽  
High Range

Novel frequency domain extracted method (FDEM) to obtain high range resolution profile (HRRP) for frequency stepped synthetic aperture radar (SAR) is proposed in this paper, and the mathematical principle and formulas of this new HRRP obtaining idea combined with classical fast Fourier transform (FFT), chirp z transform (CZT), and single point Fourier transform (SPFT) are deduced, analyzed, and compared in detail. Based on the HRRP data, precision imaging processing is completed using a data block partition based fast factorized back projection algorithm. Imaging validations are executed and all results proved that the FDEM has a great capability of antijamming. It is more effective than conventional time domain IFFT method (TDM) and shows a great promise in frequency stepped radar imaging and applications.

scholarly journals Processing Missile-Borne SAR Data by Using Cartesian Factorized Back Projection Algorithm Integrated with Data-Driven Motion Compensation

2021 ◽  
Vol 13 (8) ◽  
pp. 1462
Author(s):  
Min Bao ◽  
Song Zhou ◽  
Mengdao Xing
Keyword(s):  
Time Domain ◽  
Motion Compensation ◽  
Phase Error ◽  
Data Driven ◽  
Projection Algorithm ◽  
Compressed Domain ◽  
Fast Time ◽  
Back Projection ◽  
Motion Error ◽  
Efficient Data

Due to the independence of azimuth-invariant assumption of an echo signal, time-domain algorithms have significant performance advantages for missile-borne synthetic aperture radar (SAR) focusing with curve moving trajectory. The Cartesian factorized back projection (CFBP) algorithm is a newly proposed fast time-domain implementation which can avoid massive interpolations to improve the computational efficiency. However, it is difficult to combine effective and efficient data-driven motion compensation (MOCO) for achieving high focusing performance. In this paper, a new data-driven MOCO algorithm is developed under the CFBP framework to deal with the motion error problem for missile-borne SAR application. In the algorithm, spectrum compression is implemented after a CFBP process, and the SAR images are transformed into the spectrum-compressed domain. Then, the analytical image spectrum is obtained by utilizing wavenumber decomposition based on which the property of motion induced error is carefully investigated. With the analytical image spectrum, it is revealed that the echoes from different scattering points are aligned in the same spectrum range and the phase error becomes a spatial invariant component after spectrum compression. Based on the spectrum-compressed domain, an effective and efficient data-driven MOCO algorithm is accordingly developed for accurate error estimation and compensation. Both simulations of missile-borne SAR and raw data experiment from maneuvering highly-squint airborne SAR are provided and analyzed, which show high focusing performance of the proposed algorithm.

scholarly journals FDBP-InSAR: An Efficient Algorithm for InSAR Imaging via Frequency Domain Back Projection

2020 ◽  
Vol 12 (21) ◽  
pp. 3527
Author(s):  
Shunjun Wei ◽  
Yue Wu ◽  
Jiadian Liang ◽  
Shan Liu ◽  
Mou Wang ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Projection Algorithm ◽  
Imaging Method ◽  
Back Projection ◽  
High Quality ◽  
Phase Compensation ◽  
Coherent Integration ◽  
Uniform Grids ◽  
Point To Point ◽  
The Time Domain

High-quality focusing with accurate phase-preserving is a significant and challenging step in interferometric synthetic aperture radar (InSAR) imaging. Compared with conventional frequency-based imaging algorithms, the time-domain back-projection algorithm (TDBPA) can greatly ensure the accuracy of imaging and phase-preserving by point-to-point coherent integration but suffers from huge computational complexity. In this paper, we propose an efficient InSAR imaging method, called a frequency-domain back-projection algorithm (FDBPA), to achieve high-resolution focusing and accurate phase-preserving of InSAR imaging. More specifically, FDBPA is utilized to replace the traditional point-to-point coherent integration of TDBPA with frequency-domain transform. It divides the echo spectrum into uniform grids and transforms the range compression data into the range frequency domain. Phase compensation and non-uniform Fourier transform of the underlying scene are implemented to achieve image focusing in the wavenumber domain. Then, the interferometric phase of the target scene can be preserved by accurate phase compensation of the target’s distance. FDBPA avoids the repetitive calculation of index values and point-to-point coherent integration which reduces the time complexity compared with TDBPA. The characteristics of focusing and phase-preserving of our method are analyzed via simulations and experiments. The results demonstrate the efficiency and high-quality imaging of the FDBPA method. It can improve the imaging efficiency by more than three times, while keeping similar imaging accuracy compared with TDBPA.

scholarly journals OC-0298: EPID dosimetry at the MR-Linac using a back-projection algorithm: proof of concept

2018 ◽  
Vol 127 ◽  
pp. S155-S156
Author(s):  
I. Torres Xirau ◽  
I. Olaciregui-Ruiz ◽  
B.J. Mijnheer ◽  
B. Vivas-Maiques ◽  
U.A. van der Heide ◽  
...  
Keyword(s):  
Projection Algorithm ◽  
Proof Of Concept ◽  
Back Projection ◽  
Epid Dosimetry ◽  
Algorithm Proof
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