基于定位定向系统(position and orientation system,POS)测量数据实现补偿不适用于基线非刚性的系统,因而研究了基于回波数据的干涉相位误差补偿方法——频谱分割方法,分析了干涉相位误差与载机姿态变化造成的斜距误差之间的关系,阐明...基于定位定向系统(position and orientation system,POS)测量数据实现补偿不适用于基线非刚性的系统,因而研究了基于回波数据的干涉相位误差补偿方法——频谱分割方法,分析了干涉相位误差与载机姿态变化造成的斜距误差之间的关系,阐明了算法原理及适用条件。分析了算法的关键参数对补偿精度的影响,提出定量化的选取标准。基于相位误差随距离向变化的模型,改善了算法精度,给出了算法流程。最后利用该算法处理了实际机载双天线InSAR数据,结果表明该方法具有较高的精度,可以在缺乏测量数据的情况下完成干涉相位误差补偿。展开更多
This paper presents the estimation of three-dimensional volumetric errors of a machining center by using a tracking interferometer. A tracking interferometer is a laser interferometer with the mechanism to steer the l...This paper presents the estimation of three-dimensional volumetric errors of a machining center by using a tracking interferometer. A tracking interferometer is a laser interferometer with the mechanism to steer the laser direction to follow a target retroreflector. Based on the triangulation principle, the three-dimensional position of the target can be estimated from measured laser displacements. Its capability to measure three-dimensional positioning errors for arbitrary trajectories is important for the indirect measurement of the machine＇s kinematic model. This paper presents experimental investigation of the estimation accuracy of the multilateration-based measurement by a tracking interferometer. A tracking interferometer developed by a part of the authors is used in experiments. In the present experiment, the measured volume of target positions was 100 mm × 100 mm × 100 mm. The estimation accuracy of targets within this volume was not sufficiently high compared to the positioning error of the measured machine tool. The results of the experiment and simulation show that the estimation uncertainty is dependent on tracking interferometer locations relative to target locations. Error sensitivity analysis shows that wider distribution of tracker positions in XY improves the estimation accuracy.展开更多
Two approximations, center-beam approximation and reference digital elevation model （DEM） approximation, are used in synthetic aperture radar （SAR） motion compensation procedures. They usually introduce residual m...Two approximations, center-beam approximation and reference digital elevation model （DEM） approximation, are used in synthetic aperture radar （SAR） motion compensation procedures. They usually introduce residual motion compensation errors for airborne single-antenna SAR imaging and SAR interferometry. In this paper, we investigate the effects of residual uncompensated motion errors, which are caused by the above two approximations, on the performance of airborne along-track interferometric SAR （ATI-SAR）. The residual uncompensated errors caused by center-beam approximation in the absence and in the presence of elevation errors are derived, respectively. Airborne simulation parameters are used to verify the correctness of the analysis and to show the impacts of residual uncompensated errors on the interferometric phase errors for ATI-SAR. It is shown that the interferometric phase errors caused by the center-beam approximation with an accurate DEM could be neglected, while the interferometric phase errors caused by the center-beam approximation with an inaccurate DEM cannot be neglected when the elevation errors exceed a threshold. This research provides theoretical bases for the error source analysis and signal processing of airborne ATI-SAR.展开更多
基金Supported by the Foundation of Creating Research Group Programme, Hefei University of Technology, and Provincial Key Labora-tory "Quality Engineering of Modern Test and Manufacture" Foundation of Anhui
文摘基于定位定向系统(position and orientation system,POS)测量数据实现补偿不适用于基线非刚性的系统,因而研究了基于回波数据的干涉相位误差补偿方法——频谱分割方法,分析了干涉相位误差与载机姿态变化造成的斜距误差之间的关系,阐明了算法原理及适用条件。分析了算法的关键参数对补偿精度的影响,提出定量化的选取标准。基于相位误差随距离向变化的模型,改善了算法精度,给出了算法流程。最后利用该算法处理了实际机载双天线InSAR数据,结果表明该方法具有较高的精度,可以在缺乏测量数据的情况下完成干涉相位误差补偿。
文摘This paper presents the estimation of three-dimensional volumetric errors of a machining center by using a tracking interferometer. A tracking interferometer is a laser interferometer with the mechanism to steer the laser direction to follow a target retroreflector. Based on the triangulation principle, the three-dimensional position of the target can be estimated from measured laser displacements. Its capability to measure three-dimensional positioning errors for arbitrary trajectories is important for the indirect measurement of the machine＇s kinematic model. This paper presents experimental investigation of the estimation accuracy of the multilateration-based measurement by a tracking interferometer. A tracking interferometer developed by a part of the authors is used in experiments. In the present experiment, the measured volume of target positions was 100 mm × 100 mm × 100 mm. The estimation accuracy of targets within this volume was not sufficiently high compared to the positioning error of the measured machine tool. The results of the experiment and simulation show that the estimation uncertainty is dependent on tracking interferometer locations relative to target locations. Error sensitivity analysis shows that wider distribution of tracker positions in XY improves the estimation accuracy.
基金Project supported by the National Natural Science Foundation of China （Nos. 61331017 and 61401428）
文摘Two approximations, center-beam approximation and reference digital elevation model （DEM） approximation, are used in synthetic aperture radar （SAR） motion compensation procedures. They usually introduce residual motion compensation errors for airborne single-antenna SAR imaging and SAR interferometry. In this paper, we investigate the effects of residual uncompensated motion errors, which are caused by the above two approximations, on the performance of airborne along-track interferometric SAR （ATI-SAR）. The residual uncompensated errors caused by center-beam approximation in the absence and in the presence of elevation errors are derived, respectively. Airborne simulation parameters are used to verify the correctness of the analysis and to show the impacts of residual uncompensated errors on the interferometric phase errors for ATI-SAR. It is shown that the interferometric phase errors caused by the center-beam approximation with an accurate DEM could be neglected, while the interferometric phase errors caused by the center-beam approximation with an inaccurate DEM cannot be neglected when the elevation errors exceed a threshold. This research provides theoretical bases for the error source analysis and signal processing of airborne ATI-SAR.
