Ground-based synthetic aperture radar(GB-SAR) has been successfully applied to the ground deformation monitoring.However, due to the short length of the GB-SAR platform, the scope of observation is largely limited. Th...Ground-based synthetic aperture radar(GB-SAR) has been successfully applied to the ground deformation monitoring.However, due to the short length of the GB-SAR platform, the scope of observation is largely limited. The practical applications drive us to make improvements on the conventional linear rail GB-SAR system in order to achieve larger field imaging. First, a turntable is utilized to support the rotational movement of the radar.Next, a series of high-squint scanning is performed with multiple squint angles. Further, the high squint modulation phase of the echo data is eliminated. Then, a new multi-angle imaging method is performed in the wave number domain to expand the field of view. Simulation and real experiments verify the effectiveness of this method.展开更多
The near-Earth asteroid collisions could cause catastrophic disasters to humanity and the Earth,so it is crucial to monitor asteroids.Ground-based synthetic aperture radar(SAR)is an observation technique for high reso...The near-Earth asteroid collisions could cause catastrophic disasters to humanity and the Earth,so it is crucial to monitor asteroids.Ground-based synthetic aperture radar(SAR)is an observation technique for high resolution imaging of asteroids.The ground-based SAR requires a long integration time to achieve a large synthetic aperture,and the echo signal will be seriously affected by temporal-spatial variant troposphere.Traditional spatiotemporal freezing tropospheric models are ineffective.To cope with this,this paper models and analyses the impacts of temporal-spatial variant troposphere on ground-based SAR imaging of asteroids.For the background tropo-sphere,a temporal-spatial variant ray tracing method is proposed to trace the 4D(3D spatial+temporal)refractive index network provided by the numerical weather model,and calculate the error of the background troposphere.For the tropospheric turbulence,the Andrew power spectral model is used in conjunction with multiphase screen theory,and varying errors are obtained by tracking the changing position of the pierce point on the phase screen.Through simulation,the impact of temporal-spatial variant tropospheric errors on image quality is analyzed,and the simulation results show that the X-band echo signal is seriously affected by the troposphere and the echo signal must be compensated.展开更多
Much work has been done on radar calibration in recent years since the inversion and classification algorithms rely heavily on the precision of measured radar data. In order to take the quantitative backscattering mea...Much work has been done on radar calibration in recent years since the inversion and classification algorithms rely heavily on the precision of measured radar data. In order to take the quantitative backscattering measurement, external calibration should be carried out At precent, one of the common calibration methods is the point-target method. However,展开更多
In this paper, we discuss about the near range radar applied to various environmental applications and disaster mitigation issues. Synthetic aperture radar（SAR） processing or migration is the key technology in near ...In this paper, we discuss about the near range radar applied to various environmental applications and disaster mitigation issues. Synthetic aperture radar（SAR） processing or migration is the key technology in near range radar imaging, which can be used in ground penetrating radar（GPR） and ground-based synthetic aperture radar（GB-SAR）. We demonstrate some applications which include GPR for humanitarian demining, GPR for archaeological survey, GB-SAR for landslide monitoring and nondestructive inspection of wooden buildings. We also demonstrate a new array GPR system “Yakumo”, which was used for archaeological survey for demonstration of advanced multi-static radar signal processing for better radar imaging.展开更多
基金supported by the National Natural Science Foundation of China(61801007)the Beijing Natural Science Foundation(4194075)。
文摘Ground-based synthetic aperture radar(GB-SAR) has been successfully applied to the ground deformation monitoring.However, due to the short length of the GB-SAR platform, the scope of observation is largely limited. The practical applications drive us to make improvements on the conventional linear rail GB-SAR system in order to achieve larger field imaging. First, a turntable is utilized to support the rotational movement of the radar.Next, a series of high-squint scanning is performed with multiple squint angles. Further, the high squint modulation phase of the echo data is eliminated. Then, a new multi-angle imaging method is performed in the wave number domain to expand the field of view. Simulation and real experiments verify the effectiveness of this method.
基金supported in part by the National Natural Science Foundation of China(Nos.62101039,62201051)in part by the Shandong Excellent Young Scientists Fund Program(Overseas)in part by China Postdoctoral Science Foundation(No.2022M720443).
文摘The near-Earth asteroid collisions could cause catastrophic disasters to humanity and the Earth,so it is crucial to monitor asteroids.Ground-based synthetic aperture radar(SAR)is an observation technique for high resolution imaging of asteroids.The ground-based SAR requires a long integration time to achieve a large synthetic aperture,and the echo signal will be seriously affected by temporal-spatial variant troposphere.Traditional spatiotemporal freezing tropospheric models are ineffective.To cope with this,this paper models and analyses the impacts of temporal-spatial variant troposphere on ground-based SAR imaging of asteroids.For the background tropo-sphere,a temporal-spatial variant ray tracing method is proposed to trace the 4D(3D spatial+temporal)refractive index network provided by the numerical weather model,and calculate the error of the background troposphere.For the tropospheric turbulence,the Andrew power spectral model is used in conjunction with multiphase screen theory,and varying errors are obtained by tracking the changing position of the pierce point on the phase screen.Through simulation,the impact of temporal-spatial variant tropospheric errors on image quality is analyzed,and the simulation results show that the X-band echo signal is seriously affected by the troposphere and the echo signal must be compensated.
基金the National Natural Science Foundation of China, and CAS President Foundation.
文摘Much work has been done on radar calibration in recent years since the inversion and classification algorithms rely heavily on the precision of measured radar data. In order to take the quantitative backscattering measurement, external calibration should be carried out At precent, one of the common calibration methods is the point-target method. However,
基金"Development of Non-Destructive Inspection method for constructions by electromagnetic wave", the Commissioned Research of National Institute of Information and Communications Technology (NICT), Japan and JSPS Grant-in-Aid for Scientific Research (No. 23246076)
文摘In this paper, we discuss about the near range radar applied to various environmental applications and disaster mitigation issues. Synthetic aperture radar（SAR） processing or migration is the key technology in near range radar imaging, which can be used in ground penetrating radar（GPR） and ground-based synthetic aperture radar（GB-SAR）. We demonstrate some applications which include GPR for humanitarian demining, GPR for archaeological survey, GB-SAR for landslide monitoring and nondestructive inspection of wooden buildings. We also demonstrate a new array GPR system “Yakumo”, which was used for archaeological survey for demonstration of advanced multi-static radar signal processing for better radar imaging.
