DocumentCode :
108792
Title :
Co-Registration of Two DEMs: Impacts on Forest Height Estimation From SRTM and NED at Mountainous Areas
Author :
Wenjian Ni ; Guoqing Sun ; Zhiyu Zhang ; Zhifeng Guo ; Yating He
Author_Institution :
Key Lab. of Remote Sensing Sci., Beijing Normal Univ., Beijing, China
Volume :
11
Issue :
1
fYear :
2014
fDate :
Jan. 2014
Firstpage :
273
Lastpage :
277
Abstract :
The digital elevation model from the Shuttle Radar Topography Mission (SRTM) and the National Elevation Dataset (NED) have been used to estimate the forest canopy height. Most of such studies have been conducted over flat areas; the method performance has not been carefully examined over mountainous areas. This study, which is conducted over two mountainous test sites located in California and New Hampshire, reveals that the co-registration of these two digital elevation models (DEMs) is crucial to ensuring the quality of the results. The image co-registration method used in interferometric SAR processing is adapted to the co-registration of two DEMs. The forest canopy height from the Laser Vegetation Imaging Sensor (LVIS) is used as the reference data. The results showed that the misregistration between SRTM and NED was very obvious at both test sites. After the co-registration, the R2 of the correlation between the height of the C-band scattering phase center derived from SRTM minus NED and the forest canopy height derived from LVIS data was improved from 0.19 to 0.51, and RMSE was reduced from 16.4 m to 6.8 m for slope up to 55° at the California test site, while the R2 was improved from 0.39 to 0.57 and RMSE was reduced from 5.4 m to 3.6 m for slopes up to 45° at the New Hampshire test site. The influences of data resolution and terrain slopes were also investigated. The results showed that reducing the data resolution by spatial averaging could not reduce the influence of DEM misregistration.
Keywords :
digital elevation models; forestry; height measurement; remote sensing by laser beam; remote sensing by radar; C-band scattering phase center; California; DEM coregistration; LVIS; Laser Vegetation Imaging Sensor; National Elevation Dataset; New Hampshire; SRTM-NED misregistration; Shuttle Radar Topography Mission; USA; data resolution effects; digital elevation model; forest canopy height; forest height estimation effects; image coregistration method; interferometric SAR processing; method performance; mountainous areas; reference data; terrain slope effects; Digital elevation model (DEM) co-registration; National Elevation Dataset (NED); Shuttle Radar Topography Mission (SRTM); forest canopy height; mountain;
fLanguage :
English
Journal_Title :
Geoscience and Remote Sensing Letters, IEEE
Publisher :
ieee
ISSN :
1545-598X
Type :
jour
DOI :
10.1109/LGRS.2013.2255580
Filename :
6542016
Link To Document :
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