ACCURACY EVALUATION OF DEM DERIVED BY TERRASAR-X DATA IN THE 
HIMALAYAN REGION 
N. Yamane a *, K. Fujita b , T. Nonaka a , T. Shibayama a , and S. Takagishi a 
a PASCO CORPORATION, 2-8-10 Higashiyama, Meguro-ku, Tokyo, Japan 
naofumi_yamane@pasco.co.jp 
b Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8602, Japan 
KEY WORDS: InSAR, Glacier, Elevation, Himalayan, SAR, TerraSAR-X, Monitoring 
ABSTRACT: 
In the past few years, the Himalayan region has experienced a number of floods from glacial lakes, and the 
neighboring areas were severely damaged. Therefore it is important to continue monitoring glaciers or creating 
simulation of floods to prevent the damages in those regions. The DEM is very useful for studying these hazardous 
problems. In this study, we tried to generate DEM by TerraSAR-X images for conducting InSAR processing and 
evaluating the quality of the DEMs by comparing them with SRTM data. DEM generated by TerraSAR-X image 
could acquire more detailed surface information of the mountaneous region. The end and side of the moraine were 
recognizable with TerraSAR-X DEMs. It is expected that the InSAR DEM would be highly useful for monitoring 
purposes in the mountainous regions. 
1. INTRODUCTION 
During past years, the Himalayan region faced several 
floods from glacial lakes, and the neighboring areas 
were severely damaged (ICIMOD et al., 2007, J. 
Komori 2006., etc). If the floods can be predicted well 
in advance, the continuous actions, such as making a 
good preventive plan and allocating disaster-prevention 
facilities, can be adopted well before occurrence of the 
floods. Consequently, it is expected that the extent of 
the damage of the populated area or infrastructure can 
be greatly controlled. The Digital Elevation Model 
(DEM) is widely used for flood prediction and 
estimating the affected area and utilized for 
environmental monitoring as well. It is possible to 
detect the temporal changes of glacial lakes, glaciers 
and moraines by comparing two DEMs produced at two 
different time intervals. 
DEMs produced from optical satellite images have been 
commonly used for glacier monitoring. However, the 
problem is to obtain cloud free images. Most of the 
glacial lake outburst flood (GLOF) occurs in the 
monsoon season and therefore, monitoring the glaciers 
is very difficult due to bad weather conditions and 
presence of dense clouds. Data acquisitions, 
irrespective of weather conditions, by the Synthetic 
Aperture Radar (SAR) satellites of C, L and X bands 
can create DEMs. 
On June 2007 TerraSAR-X satellite was successfully 
launched and presently providing images for the global 
users. The X-band radar is capable of extracting 
surface features information better than C-band or L- 
band sensors due to the short wavelength. Additionaly 
DEMs created from X-band sensor satellite images 
were not generated by interferometry till recently. 
The purpose of this study was to generate DEMs from 
TerraSAR-X images utilizing InSAR and evaluating the 
qualitative accuracy by comparing with Shuttle Radar 
Topography Mission (SRTM) data. 
2. METHODOLOGY 
In this study, we made our attempts to cover DEMs 
from a pair of TerraSAR-X images obtained by High 
resolution SpotLight (HS) and StripMap (SM) modes 
images. After generating the DEMs, we also evaluated 
the qualitative accuracy of the DEMs while comparing 
SRTM data for the entire study area. 
Corresponding author. This is useful to know for communication with the appropriate person in cases with more than one 
author.