Due to the short laser wavelength, almost all practical targets are rough. Surface elevations in rough targets will result in layovers in synthetic aperture ladar （SAL）. High resolution SAL image with layovers will ...Due to the short laser wavelength, almost all practical targets are rough. Surface elevations in rough targets will result in layovers in synthetic aperture ladar （SAL）. High resolution SAL image with layovers will be different fi＇om the target picture taken by incoherent tools as digital camera. To investigate the layovers in SAL image, a simplified mathematical model is built by optics diffraction theory and a laboratory SAL is setup using 1550 mn tunable laser source. Layovers in SAL images, in both theoretical simulation and experimental demonstra- tion, are carefully observed. Detailed results on various targets are illustrated.展开更多
The Surface Water and Ocean Topography(SWOT)mission represents a collaborative effort between physical oceanography and hydrology fields,aimed at exchanging detailed topography information characterized by its high pr...The Surface Water and Ocean Topography(SWOT)mission represents a collaborative effort between physical oceanography and hydrology fields,aimed at exchanging detailed topography information characterized by its high precision in vertical measurements and extensive spatial detail.This data is generated by a scientific payload,with the Ka-band radar Interferometer(KaRin)serving as its primary tool.However,its smaller incidence angle increases layover regions,introducing noise during observations.Focused on four rugged high-altitude Xizang Plateau regions,this study evaluates the simulation of areas that are not affected by the Synthetic Aperture Radar(SAR)side-looking mode,using simulated SWOT orbit parameters and Digital Elevation Model(DEM)data derived from Shuttle Radar Topography Mission(SRTM).The results show that the imaging mode of KaRIn induces layover in terrain with significant variations,challenging precise topography retrieval.Utilizing the left and right swaths of swOT could enhance the observations along the east and west axis,suggesting multiple observations are necessary for the accuracy of surface terrain.The detection results of the lake mask show that KaRIn is adept at monitoring lakes,though their boundaries could be affected by adjacent riverbanks and nearby mountainous landscapes.The importance of mitigating layover impact cannot be overstated for heightened precision and expanded applications,thereby raising the significance of sWOT in environmental and scientific studies.展开更多
文摘Due to the short laser wavelength, almost all practical targets are rough. Surface elevations in rough targets will result in layovers in synthetic aperture ladar （SAL）. High resolution SAL image with layovers will be different fi＇om the target picture taken by incoherent tools as digital camera. To investigate the layovers in SAL image, a simplified mathematical model is built by optics diffraction theory and a laboratory SAL is setup using 1550 mn tunable laser source. Layovers in SAL images, in both theoretical simulation and experimental demonstra- tion, are carefully observed. Detailed results on various targets are illustrated.
基金supported by the National Natural Science Foundation of China(grant nos.42274028 and 41704023).
文摘The Surface Water and Ocean Topography(SWOT)mission represents a collaborative effort between physical oceanography and hydrology fields,aimed at exchanging detailed topography information characterized by its high precision in vertical measurements and extensive spatial detail.This data is generated by a scientific payload,with the Ka-band radar Interferometer(KaRin)serving as its primary tool.However,its smaller incidence angle increases layover regions,introducing noise during observations.Focused on four rugged high-altitude Xizang Plateau regions,this study evaluates the simulation of areas that are not affected by the Synthetic Aperture Radar(SAR)side-looking mode,using simulated SWOT orbit parameters and Digital Elevation Model(DEM)data derived from Shuttle Radar Topography Mission(SRTM).The results show that the imaging mode of KaRIn induces layover in terrain with significant variations,challenging precise topography retrieval.Utilizing the left and right swaths of swOT could enhance the observations along the east and west axis,suggesting multiple observations are necessary for the accuracy of surface terrain.The detection results of the lake mask show that KaRIn is adept at monitoring lakes,though their boundaries could be affected by adjacent riverbanks and nearby mountainous landscapes.The importance of mitigating layover impact cannot be overstated for heightened precision and expanded applications,thereby raising the significance of sWOT in environmental and scientific studies.
