Range determination with waveform recording laser systems using a Wiener Filter
Range determination with waveform recording laser systems using a Wiener Filter
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DOI：
10.1016/j.isprsjprs.2006.09.001
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发表时间：
2006-11-01
影响因子：
12.7
通讯作者：
Stilla, Uwe
中科院分区：
文献类型：
--
作者：
Jutzi, Boris;Stilla, Uwe
当前的脉冲激光扫描系统通过飞行时间测量来确定到物体表面的距离。关键的测量情况发生在区分靠近其边缘的表面的范围或光束足迹内靠近距离的小物体的范围。捕获激光脉冲的完整波形允许在小于激光脉冲长度的范围内区分差异。通过对发射脉冲、表面和后向散射脉冲进行建模，可以预测该技术的性能。由于发射脉冲的波形变化，每个单独发射的脉冲被记录下来，并被考虑用于确定表面特征。反褶积用于从接收波形中去除发射波形的特征，以获得表面响应。维纳滤波器减少了确定的表面响应的噪声。对于时间位置、长度和振幅的提取，使用Levenberg-Marquardt方法对相应的表面特征进行高斯近似。实验表明，在光束内部可以分辨出一个步长小于10倍脉冲长度的阶梯状表面。(C) 2006国际摄影测量与遥感学会（ISPRS）Elsevier B.V.版权所有。
Current pulsed laser scanning systems determine the range to an object surface by a time-of-flight measurement. Critical measurement situations occur in discriminating the ranges of surfaces close to their edges or of small objects within the beam footprint which are closely located in range. Capturing the complete waveform of the laser pulse allows discriminating differences in a range smaller than the length of the laser pulse. The capabilities of this technique can be predicted by modeling the emitted pulse, the surface, and the backscattered pulse. Due to the varying waveforms of the emitted pulses each individual emitted pulse is recorded and considered for the determination of the surface features. A deconvolution is used to remove the characteristic of the transmitted waveform from the received waveform to obtain a surface response. A Wiener Filter reduces the noise of the determined surface response. For extraction of temporal position, length, and amplitude the corresponding surface features are approximated by Gaussians using the Levenberg-Marquardt Method. Experiments have shown that a stepped surface within the beam with a step smaller than ten times of the pulse length can be distinguished. (C) 2006 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved.