Using waveform matching to precisely locate footprints of a satellite laser altimeter

Zhang Wenhao; Li Song; Zhang Zhiyu; Liu Rui; Ma Yue

doi:10.3788/IRLA201847.1117007

The footprints of a satellite laser altimeter have an elevation accuracy of the decimeter order, which satisfies the elevation accuracy needs of ground control points (GCP) for mapping. However, the horizontal accuracy of footprints is only few tens of meters, and only the footprints illuminating on flat ground targets can be used as GCPs. In this paper, the waveform model was derived and used to develop a waveform simulator of laser altimeters. Compared with the current method of waveform matching, the new simulator considered more detailed effects arising from the device and target, e.g., time and spatial distribution of lasers, surface profile, and surface reflectivity. The airborne LiDAR point cloud and the Geoscience Laser Altimeter System(GLAS) data were involved to match the best-fit waveform by maximizing the correlation coefficients of the simulated waveform and GLAS waveform, and the precise location of every GLAS footprint could be acquired where the correlation coefficient was the maximum. The results show that, the mean of maximum correlation coefficients is more than 0.9 during the GLAS operating periods with normal received energies, and the horizontal accuracy of footprints is approximately 2 m after the waveform matching. The proposed method can be used to extract the laser GCPs on complex relief of the surface.

Using waveform matching to precisely locate footprints of a satellite laser altimeter

1. School of Electronic Information,Wuhan University,Wuhan 430079,China

Received Date: 2018-06-10

Rev Recd Date: 2018-07-20

Publish Date: 2018-11-25

Key words:

Abstract: The footprints of a satellite laser altimeter have an elevation accuracy of the decimeter order, which satisfies the elevation accuracy needs of ground control points (GCP) for mapping. However, the horizontal accuracy of footprints is only few tens of meters, and only the footprints illuminating on flat ground targets can be used as GCPs. In this paper, the waveform model was derived and used to develop a waveform simulator of laser altimeters. Compared with the current method of waveform matching, the new simulator considered more detailed effects arising from the device and target, e.g., time and spatial distribution of lasers, surface profile, and surface reflectivity. The airborne LiDAR point cloud and the Geoscience Laser Altimeter System(GLAS) data were involved to match the best-fit waveform by maximizing the correlation coefficients of the simulated waveform and GLAS waveform, and the precise location of every GLAS footprint could be acquired where the correlation coefficient was the maximum. The results show that, the mean of maximum correlation coefficients is more than 0.9 during the GLAS operating periods with normal received energies, and the horizontal accuracy of footprints is approximately 2 m after the waveform matching. The proposed method can be used to extract the laser GCPs on complex relief of the surface.

HTML

Reference (13)

[1]	Schutz B. E. Overview of ICESat mission[J]. Geophysical Research Letters, 2005, 32:L21S01.
[2]	Brenner A C, DiMarzio J P, Zwally H J. Precision and accuracy of satellite radar and laser altimeter data over the continental ice sheets[J]. IEEE Transactions on Geoscience and Remote Sensing, 2007, 45(2):321-331.
[3]	Li G Y, Tang X M, Gao X M, et al. ZY-3 Block adjustment supported by GLAS laser altimetry data[J]. The Photogrammetric Record, 2016, 31(153):88-107.
[4]	Markus T, Neumann T, Martino A, et al. The ice, cloud, and land elevation satellite-2(ICESat-2):science requirements, concept, and implementation[J]. Remote Sensing of Environment, 2017, 190:260-273.
[5]	Harding D J, Carabajal C C. ICESat waveform measurements of within-footprint topographic relief and vegetation vertical structure[J]. Geophysical Research Letters, 2005, 32(21):S10.
[6]	Yadav G K. Simulation of ICESat/GLAS full-waveform over highly rugged terrain[D]. Netherlands Enschede:University of Twente, 2008.
[7]	Magruder L, Silverberg E, Webb C, et al. In situ timing and pointing verification of the ICESat altimeter using a ground-based system[J]. Geophysical Research Letters, 2005, 32(21):365-370.
[8]	Magruder L A, Webb C E, Urban T J, et al. ICESat altimetry data product verification at White Sands Space Harbor[J]. IEEE Transactions on Geoscience Remote Sensing, 2006, 45(1):147-155.
[9]	Yue Chunyu, Xing Kun, Bao Yunfei, et al. A matching method of space-borne laser altimeter big footprint waveform and terrain based on cross cumulative residual entropy[J]. Acta Geodaetica et Cartograohica Sinica, 2017, 46(3):346-352. (in Chinese)岳春宇, 邢坤, 鲍云飞,等. 以交叉累积剩余熵为准则的星载激光测高仪大光斑波形数据与地形匹配法[J]. 测绘学报, 2017, 46(3):346-352.
[10]	Tang Xinming, Xie Junfeng, Fu Xingke, et al. Laser altimeter on-orbit geometrical calibration and test[J]. Acta Geodaeticaet Cartographica Sinica, 2017, 46(6):714-723. (in Chinese)唐新明, 谢俊峰, 付兴科, 等. 资源三号02星激光测高仪在轨几何检校与试验验证[J]. 测绘学报, 2017, 46(6):714-723.
[11]	Zwally H J, Schutz B E, Hancock D W. GLAS standard data products specification-Level 1/2 Version 8.0[R]. ICESat (GLAS) science processing software document series volume, 2005:11.
[12]	Abshire J B, Sun X, Riris H, et al. Geoscience Laser Altimeter System (GLAS) on the ICESat Mission:On-orbit measurement performance[J]. Geophysical Research Letters, 2005, 32(21):S02.
[13]	Neuenschwander A L, Urban T J, Gutierrez R, et al. Characterization of icesat/glas waveforms over terrestrial ecosystems:implications for vegetation mapping[J]. Journal of Geophysical Research Atmospheres, 2008, 113(G2):1032-1032.

Using waveform matching to precisely locate footprints of a satellite laser altimeter

doi: 10.3788/IRLA201847.1117007

Abstract

References

Proportional views

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Related

Proportional views