The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. ex. Some numerals are expressed as "XNUMX".
Copyrights notice
The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. Copyrights notice
Dengan pembangunan radar apertur sintetik bawaan angkasa (SAR), resolusi spatial ultra tinggi telah menjadi topik hangat sejak beberapa tahun kebelakangan ini. Sistem dengan resolusi spatial tinggi meminta lebar jalur julat besar dan masa penyepaduan azimut yang panjang. Walau bagaimanapun, disebabkan oleh masa penyepaduan azimut yang panjang, banyak masalah timbul, yang tidak boleh diabaikan dalam mod lampu sorot resolusi ultra-tinggi operasi. Kertas kerja ini menyiasat dua isu kritikal yang perlu diberi perhatian untuk pemprosesan apertur penuh data lampu sorot SAR bawaan angkasa resolusi ultra tinggi. Yang pertama ialah ketidaktepatan model julat hiperbolik tradisional (HRM) apabila sistem menghampiri resolusi julat desimeter. Yang kedua ialah fenomena lipatan spektrum azimut. Masalah yang dinyatakan di atas mengakibatkan kemerosotan ketara kesan pemfokusan. Oleh itu, untuk menyelesaikan masalah ini, skim pemprosesan apertur penuh dicadangkan dalam kertas ini yang menggabungkan kelebihan dua algoritma pemprosesan yang digunakan secara umum: ketepatan algoritma pampasan gerakan satu langkah (MOCO) dan kecekapan pemprosesan dua langkah yang diubah suai. pendekatan (TSA). Pertama, algoritma MOCO satu langkah, algoritma MOCO tercanggih yang telah digunakan dalam sistem SAR bawaan udara resolusi ultra tinggi, boleh membetulkan dengan tepat ralat yang disebabkan oleh orbit lengkung bawaan angkasa. Kedua, TSA yang diubah suai boleh mengelakkan fenomena lipatan spektrum azimut dengan berkesan. Perkara utama TSA yang diubah suai ialah pendekatan deramping yang dijalankan melalui operasi lilitan. Fungsi rujukan, berbeza dengan frekuensi julat serta-merta, diguna pakai oleh operasi lilitan untuk mendapatkan spektrum terbentang dalam arah azimut. Selepas operasi ini, algoritma domain nombor gelombang tradisional tersedia kerana ralat yang disebabkan oleh orbit lengkung bawaan angkasa dan pengaruh lipatan spektrum dalam arah azimut telah diselesaikan sepenuhnya. Berdasarkan skim pemprosesan ini, data lampu sorot SAR bawaan angkasa ultra tinggi boleh difokuskan dengan baik. Prestasi skim pemprosesan apertur penuh ditunjukkan oleh simulasi sasaran titik.
Tianshun XIANG
The Nanjing University of Aeronautics and Astronautics
Daiyin ZHU
The Nanjing University of Aeronautics and Astronautics
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Salinan
Tianshun XIANG, Daiyin ZHU, "Full-Aperture Processing of Ultra-High Resolution Spaceborne SAR Spotlight Data Based on One-Step Motion Compensation Algorithm" in IEICE TRANSACTIONS on Communications,
vol. E102-B, no. 2, pp. 247-256, February 2019, doi: 10.1587/transcom.2018ISP0018.
Abstract: With the development of spaceborne synthetic aperture radar (SAR), ultra-high spatial resolution has become a hot topic in recent years. The system with high spatial resolution requests large range bandwidths and long azimuth integration time. However, due to the long azimuth integration time, many problems arise, which cannot be ignored in the operational ultra-high resolution spotlight mode. This paper investigates two critical issues that need to be noticed for the full-aperture processing of ultra-high resolution spaceborne SAR spotlight data. The first one is the inaccuracy of the traditional hyperbolic range model (HRM) when the system approaches decimeter range resolution. The second one is the azimuth spectral folding phenomenon. The problems mentioned above result in significant degradation of the focusing effect. Thus, to solve these problems, a full-aperture processing scheme is proposed in this paper which combines the superiorities of two generally utilized processing algorithms: the precision of one-step motion compensation (MOCO) algorithm and the efficiency of modified two-step processing approach (TSA). Firstly, one-step MOCO algorithm, a state-of-the-art MOCO algorithm which has been applied in ultra-high resolution airborne SAR systems, can precisely correct for the error caused by spaceborne curved orbit. Secondly, the modified TSA can avoid the phenomenon of azimuth spectrum folding effectively. The key point of the modified TSA is the deramping approach which is carried out via the convolution operation. The reference function, varying with the instantaneous range frequency, is adopted by the convolution operation for obtaining the unfolding spectrum in azimuth direction. After these operations, the traditional wavenumber domain algorithm is available because the error caused by spaceborne curved orbit and the influence of the spectrum folding in azimuth direction have been totally resolved. Based on this processing scheme, the ultra-high resolution spaceborne SAR spotlight data can be well focused. The performance of the full-aperture processing scheme is demonstrated by point targets simulation.
URL: https://global.ieice.org/en_transactions/communications/10.1587/transcom.2018ISP0018/_p
Salinan
@ARTICLE{e102-b_2_247,
author={Tianshun XIANG, Daiyin ZHU, },
journal={IEICE TRANSACTIONS on Communications},
title={Full-Aperture Processing of Ultra-High Resolution Spaceborne SAR Spotlight Data Based on One-Step Motion Compensation Algorithm},
year={2019},
volume={E102-B},
number={2},
pages={247-256},
abstract={With the development of spaceborne synthetic aperture radar (SAR), ultra-high spatial resolution has become a hot topic in recent years. The system with high spatial resolution requests large range bandwidths and long azimuth integration time. However, due to the long azimuth integration time, many problems arise, which cannot be ignored in the operational ultra-high resolution spotlight mode. This paper investigates two critical issues that need to be noticed for the full-aperture processing of ultra-high resolution spaceborne SAR spotlight data. The first one is the inaccuracy of the traditional hyperbolic range model (HRM) when the system approaches decimeter range resolution. The second one is the azimuth spectral folding phenomenon. The problems mentioned above result in significant degradation of the focusing effect. Thus, to solve these problems, a full-aperture processing scheme is proposed in this paper which combines the superiorities of two generally utilized processing algorithms: the precision of one-step motion compensation (MOCO) algorithm and the efficiency of modified two-step processing approach (TSA). Firstly, one-step MOCO algorithm, a state-of-the-art MOCO algorithm which has been applied in ultra-high resolution airborne SAR systems, can precisely correct for the error caused by spaceborne curved orbit. Secondly, the modified TSA can avoid the phenomenon of azimuth spectrum folding effectively. The key point of the modified TSA is the deramping approach which is carried out via the convolution operation. The reference function, varying with the instantaneous range frequency, is adopted by the convolution operation for obtaining the unfolding spectrum in azimuth direction. After these operations, the traditional wavenumber domain algorithm is available because the error caused by spaceborne curved orbit and the influence of the spectrum folding in azimuth direction have been totally resolved. Based on this processing scheme, the ultra-high resolution spaceborne SAR spotlight data can be well focused. The performance of the full-aperture processing scheme is demonstrated by point targets simulation.},
keywords={},
doi={10.1587/transcom.2018ISP0018},
ISSN={1745-1345},
month={February},}
Salinan
TY - JOUR
TI - Full-Aperture Processing of Ultra-High Resolution Spaceborne SAR Spotlight Data Based on One-Step Motion Compensation Algorithm
T2 - IEICE TRANSACTIONS on Communications
SP - 247
EP - 256
AU - Tianshun XIANG
AU - Daiyin ZHU
PY - 2019
DO - 10.1587/transcom.2018ISP0018
JO - IEICE TRANSACTIONS on Communications
SN - 1745-1345
VL - E102-B
IS - 2
JA - IEICE TRANSACTIONS on Communications
Y1 - February 2019
AB - With the development of spaceborne synthetic aperture radar (SAR), ultra-high spatial resolution has become a hot topic in recent years. The system with high spatial resolution requests large range bandwidths and long azimuth integration time. However, due to the long azimuth integration time, many problems arise, which cannot be ignored in the operational ultra-high resolution spotlight mode. This paper investigates two critical issues that need to be noticed for the full-aperture processing of ultra-high resolution spaceborne SAR spotlight data. The first one is the inaccuracy of the traditional hyperbolic range model (HRM) when the system approaches decimeter range resolution. The second one is the azimuth spectral folding phenomenon. The problems mentioned above result in significant degradation of the focusing effect. Thus, to solve these problems, a full-aperture processing scheme is proposed in this paper which combines the superiorities of two generally utilized processing algorithms: the precision of one-step motion compensation (MOCO) algorithm and the efficiency of modified two-step processing approach (TSA). Firstly, one-step MOCO algorithm, a state-of-the-art MOCO algorithm which has been applied in ultra-high resolution airborne SAR systems, can precisely correct for the error caused by spaceborne curved orbit. Secondly, the modified TSA can avoid the phenomenon of azimuth spectrum folding effectively. The key point of the modified TSA is the deramping approach which is carried out via the convolution operation. The reference function, varying with the instantaneous range frequency, is adopted by the convolution operation for obtaining the unfolding spectrum in azimuth direction. After these operations, the traditional wavenumber domain algorithm is available because the error caused by spaceborne curved orbit and the influence of the spectrum folding in azimuth direction have been totally resolved. Based on this processing scheme, the ultra-high resolution spaceborne SAR spotlight data can be well focused. The performance of the full-aperture processing scheme is demonstrated by point targets simulation.
ER -