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- 摘要
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- 实验方案
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - End-to-End Simulator of Geosynchronous SAR Data for System Performance Assessment
摘要： The paper describes an end-to-end simulator for Geosynchronous SAR data. The tool is composed of two modules: a raw data time domain simulator and a processor for the generation of the L1 products. The simulated raw data include the effects of atmospheric and clutter decorrelation. The end-to-end simulator is a powerful and flexible tool to be used during the system design phase for the verification of the expected performance.
关键词： APS,clutter,decorrelation,Geosynchronous SAR,end-to-end simulator
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Spacecraft Formation Design for Bistatic SAR with GEO Illuminator and LEO Receiver
摘要： The bistatic synthetic aperture radar (BiSAR) system consists of a geosynchronous Earth orbit (GEO) illuminator and a low Earth orbit (LEO) receiver. Compared with GEO SAR, it offers great advantages of higher signal-to-noise ratio (SNR) and finer spatial resolution with lower system complexity. The concept also raises significant technical challenges. The spacecraft formation has great effect on radar performance, such as spatial resolution, the angle of two-dimensional (2-D) resolution direction and noise-equivalent sigma zero (NESZ). This paper establishes the relationship between the imaging performance and the formation parameters. Then, a novel design method of spacecraft formation is presented, identifying the principal formation design choices and constraints. Finally, simulation results are provided for typical observational tasks, to verify the effectiveness of the proposed method.
关键词： imaging performance,spacecraft formation,bistatic SAR,geosynchronous
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Feasibility of Passive Bistatic Geosynchronous Radar Using Comsat Transmissions
摘要： Communications satellites in geosynchronous orbit are increasingly broadcasting digital signals with high bandwidth and high power. These signals are in principle well-suited to radar imaging and the study presented here is an initial feasibility study for a passive bistatic synthetic aperture radar using satellites in geosynchronous orbit (GEO). The persistent viewing possible from GEO could enable important new applications. The mission concept is outlined and studies of the available signal formats identify digital TV broadcasts in Ku-band as most suitable for radar imaging. The additional space hardware required is a dedicated receive channel, which could be implemented as a hosted payload at modest cost. Our findings so far suggest that the mission concept is feasible for coarse spatial resolution images and that it could therefore provide a low-cost technology demonstration of geosynchronous radar.
关键词： passive,comsat,bistatic,geosynchronous,radar
更新于2025-09-23 15:22:29
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[IEEE 2018 China International SAR Symposium (CISS) - Shanghai (2018.10.10-2018.10.12)] 2018 China International SAR Symposium (CISS) - 3D Velocity Estimation for Moving Targets via Geosynchronous Bistatic SAR
摘要： Recently, geosynchronous synthetic aperture radar (GEO-SAR), which can achieve continuous Earth observation missions with large coverage and short revisit period, has drawn extensive attention. The wide-swath imaging mode of GEO-SAR presents great potentials for bistatic observation applications. Geosynchronous bistatic SAR (GEO-BiSAR) can not only imaging task, but also provide the complete conditions for ground moving-target indication (GMTI). In this paper, the 3D velocity estimation for moving target via GEO-BiSAR are investigated. And the velocity estimation problem is extended to three-dimensional (3D) domain, considering that targets always move in a 3D space. To solve the 3D velocity of moving targets via GEO-BiSAR, the 3D velocity raw signal model is established, and a method based on fractional Fourier transform (FrFT) is proposed. First, the Doppler centroids and Doppler rates in the GEO-BiSAR are estimated by the FrFT. Second, one of the Doppler rates is used to estimate the azimuth velocity. Then, the range and height velocity are obtained by solving a Doppler centroid equation set. Finally, simulation experiments are presented to demonstrate the effectiveness of the method.
关键词： 3D Velocity Estimation,GMTI,fractional Fourier transform,Geosynchronous bistatic SAR
更新于2025-09-23 15:22:29
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A Two-Step Nonlinear Chirp Scaling Method for Multichannel GEO Spaceborne-Airborne Bistatic SAR Spectrum Reconstructing and Focusing
摘要： Due to the high-altitude illumination and the separation of the receiver and transmitter, geosynchronous (GEO) spaceborne–airborne bistatic synthetic aperture radar (BiSAR) is more ?exible and accessible in remote sensing applications. In this paper, the Doppler characteristics of GEO BiSAR with a squint receiver are analyzed. It is found that the Doppler spectrum is generally aliased in GEO BiSAR regarding the low pulse repetition frequency (PRF) adopted by the GEO SAR. In order to suppress the ambiguity without adjusting the PRF of GEO SAR, the azimuth multichannel receiving technique is applied to the receiver and then the multichannel transfer function for GEO BiSAR is derived. However, the whole bandwidth of the imaging scene is much larger than that of the center point, which requires extra receiving channels to suppress the ambiguity and thereby increasing the system complexity. A two-step nonlinear chirp scaling (NLCS) method is proposed to obtain the well-focused image with reduced receiving channels. First, a preprocessing step is conducted to achieve space-variant range cell migration correction. After that, the ?rst-step NLCS processing is applied to equalize the 2-D space-variant Doppler centroid and thereby the Doppler bandwidth is decreased, i.e., the required number of receiving channels for reconstruction is reduced. Then, the unambiguous spectrum is reconstructed based on the proposed multichannel transfer function. Finally, the second-step NLCS processing is carried out to equalize the 2-D space-variant high-order Doppler parameters and obtain the well-focused image. The simulation results validate the effectiveness of the proposed method. With the proposed two-step NLCS method, the well-focused image for GEO BiSAR is obtained and the required number of receiving channels can be decreased, which is bene?cial to reducing the system complexity and hardware cost.
关键词： azimuth spectrum aliasing,geosynchronous synthetic aperture radar (GEO SAR),bistatic SAR (BiSAR),multichannel SAR,nonlinear chirp scaling (NLCS) algorithm,Ambiguity suppression
更新于2025-09-19 17:15:36
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-band Geosynchronous D-InSAR System: Models and Analysis
摘要： The upcoming L-band geosynchronous differential interferometric synthetic aperture radar (GEO D-InSAR) system has the capability to monitor rapid deformations due to its excellent revisit capability. However, because of its low working frequency, the random ionospheric scintillation signal will degrade the deformation retrieval accuracy by giving rise to extra interferometric phase errors and obvious decorrelations in GEO D-InSAR interferograms. In this paper, aiming at impacts of ionospheric scintillations on GEO D-InSAR system, we theoretically establish its interferometric phase error and decorrelation models by using the scintillation statistical parameters directly. Simulations based on the scintillation sampling model, the Cornell university scintillation model, the phase screen mode, and the ionospheric scintillation signal acquired by the ground-based global positioning system receiver are carried out to verify the proposed model. Moreover, quantitative analyses of the ionospheric scintillation interferometric phase error and decorrelation impacts under different scintillation cases are obtained. The results verify that the proposed models and the analyses are effective. Meanwhile, they also suggest that the generated defocusing decorrelation dominates the ionospheric scintillation impacts on GEO D-InSAR, which can induce a coherence loss of more than 0.1 in the interferogram when only one image of the interferometric pair suffers the weak ionospheric scintillation.
关键词： Decorrelation effect,geosynchronous synthetic aperture radar (GEO SAR),differential interferometric synthetic aperture radar (D-InSAR),ionospheric scintillation
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Enabling Behind-the-Meter Distributed Energy Resources to Provide Grid Services
摘要： We discuss the effects of the clutter on geosynchronous SAR systems exploiting long integration times (from minutes to hours) to counteract for two-way propagation losses and increase azimuth resolution. Only stable targets will be correctly focused whereas unstable targets will spread their energy along azimuth direction. We derive here a generic model for the spreading of the clutter energy based on the power spectral density of the clutter itself. We then assume the Billingsley Intrinsic Clutter Motion model, representing the clutter power spectrum as an exponential decay, and derive the expected GEOSAR signal-to-clutter ratio. We also provide some results from a Ground Based RADAR experiment aimed at assessing the long-term clutter statistics for different scenarios to complement the Internal Clutter Motion model, mainly derived for windblown trees. Finally, we discuss the expected performances of two GEOSAR systems with different acquisition geometries.
关键词： scene decorrelation,Focusing,wind-blown clutter,Geosynchronous Synthetic Aperture Radar (GEOSAR)
更新于2025-09-19 17:13:59
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[IEEE 2018 9th International Conference on Mechanical and Aerospace Engineering (ICMAE) - Budapest (2018.7.10-2018.7.13)] 2018 9th International Conference on Mechanical and Aerospace Engineering (ICMAE) - Trajectory Estimation for a Ballistic Missile in Ballistic Phase using IR Images
摘要： It is possible to respond to threats of ballistic missile by using IR images from a geosynchronous satellite. However, IR images from the geosynchronous satellite are mainly used to detect ballistic missile, not to track. In this paper, we proposed a trajectory tracking algorithm for the ballistic missile using satellite IR image. The proposed algorithm estimates the trajectory of the ballistic missile by solving the optimization problem to find the initial value of the midcourse phase. For the ballistic missile flight and IR image measurement simulation, a pseudo 6-DOF was constructed and numerically showed the performance of the proposed algorithm.
关键词： geosynchronous satellite,IR images,optimization,ballistic missile,trajectory estimation
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Moving Target Detection and Imaging for Geosynchronous SAR
摘要： Compared with stationary targets imaging, detection and imaging of moving targets becomes more difficult in Geosynchronous synthetic aperture radar (GEOSAR), especially when the moving target is drowned in strong ground clutter. In this paper, a scheme of moving target detection and imaging with three antennas is proposed for GEOSAR. Firstly, the displaced phase center antenna (DPCA) is used to eliminate stationary targets’ echo. Then, the third-order keystone transform is applied to correct the range migration. Next, after coherent integration, the constant false alarm ratio (CFAR) is used to detect the moving target. Finally, simulation results demonstrate the effectiveness of the proposed scheme.
关键词： clutter elimination,displaced phase center antenna (DPCA),Geosynchronous synthetic aperture radar (GEOSAR)
更新于2025-09-10 09:29:36
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia, Spain (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Geosynchronous Continental Land-Atmosphere Sensing System (G-Class): Persistent Radar Imaging for Earth Science
摘要： More frequent imaging of Earth system processes is recognised as one of the emerging needs in Earth observation. Conventional low Earth orbit satellites are limited in their ability to provide this, whereas satellites in geosynchronous orbit can in principle provide continuous imaging. A new mission design has been developed from studies for a previous geosynchronous radar mission concept (GeoSTARe) to improve its technical feasibility and geographical coverage, and to reinforce its science focus. This new mission (Geosynchronous-Continental Land Atmosphere Sensing System (G-CLASS)) is presented. G-CLASS is in fact a family of missions: we present a version focussed on the diurnal water cycle - G-CLASS:H2O - for which geosynchronous radar has great potential. G-CLASS:H2O is being developed as a proposal for ESA’s Earth Explorer programme.
关键词： GeoSTARe,water,radar,geosynchronous,G-CLASS
更新于2025-09-10 09:29:36