Accuracy assessment of the processed SRTM-based elevation data by CGIAR using field data from USA and Thailand and its relation to the terrain characteristics

Shuttle radar topographic mission (SRTM) has created an unparalleled data set of global elevations that is freely available for modeling and environmental applications. The global availability (almost 80% of the Earth surface) of SRTM data provides baseline information for many types of the worldwide research. The processed SRTM 90 m digital elevation model (DEM) for the entire globe was compiled by Consultative Group for International Agriculture Research Consortium for Spatial Information (CGIAR-CSI) and made available to the public via internet mapping interface. This product presents a great value for scientists dealing with terrain analysis, thanks to its easy download procedure and ready-to-use format. However, overall assessment of the accuracy of this product requires additional regional studies involving ground truth control and accuracy verification methods with higher level of precision, such as the global positioning system (GPS). The study presented in this paper is based on two independent datasets collected with the same GPS system in Catskill Mountains (New York, USA) and Phuket (Thailand). Both datasets were corrected with differential base station data. Statistical analysis included estimation of absolute errors and multiple regression analysis with slope and aspect variables. Data were analyzed for each location separately and in combination. Differences in terrain and geographical location allowed independent interpretation of results. The results of this study showed that absolute average vertical errors from CGIAR dataset can range from 7.58±0.60 m in Phuket to 4.07± 0.47 m in Catskills (mean±S.E.M.). This is significantly better than a standard SRTM accuracy value indicated in its specification (i.e. 16 m). The error values have strong correlation with slope and certain aspect values. Taking into account slope and aspect considerably improved the accuracy of the CGIAR DEM product for terrain with slope values greater than 10°; however, for the terrain with slope values less than 10°, this improvement was found to be negligible. © 2006 Elsevier Inc. All rights reserved.

[1]  Jay A. Farrell,et al.  Differential carrier phase GPS-aided INS for automotive applications , 1999, Proceedings of the 1999 American Control Conference (Cat. No. 99CH36251).

[2]  M. Murnane,et al.  Active synchronization and carrier phase locking of two separate mode-locked femtosecond lasers , 2002 .

[3]  Angela Lee,et al.  Perspectives on … Environmental Systems Research Institute, Inc , 1997 .

[4]  David T. Sandwell,et al.  Accuracy and resolution of shuttle radar topography mission data , 2003 .

[5]  Steve Dowding,et al.  VOID FILL OF SRTM ELEVATION DATA - PRINCIPLES, PROCESSES AND PERFORMANCE , 2002 .

[6]  Han-Shue Tan,et al.  Carrier Phase GPS-Aided INS-Based Vehicle Lateral Control , 2003 .

[7]  Kevin Amaratunga,et al.  Analysis and characterization of the vertical accuracy of digital elevation models from the Shuttle Radar Topography Mission , 2005 .

[8]  Mark Mulligan,et al.  Practical use of SRTM data in the tropics : Comparisons with digital elevation models generated cartographic data , 2004 .

[9]  G. Miliaresis,et al.  Vertical accuracy of the SRTM DTED level 1 of Crete , 2005 .

[10]  W. O. Thomas,et al.  Nationwide summary of US Geological Survey regional regression equations for estimating magnitude and frequency of floods for ungaged sites, 1993 , 1994 .

[11]  T. Farr,et al.  Shuttle radar topography mission produces a wealth of data , 2000 .

[12]  G.W. Hein,et al.  Development of a real-time DGPS system in the centimeter range , 1994, Proceedings of 1994 IEEE Position, Location and Navigation Symposium - PLANS'94.

[13]  G. Suna,et al.  Validation of surface height from shuttle radar topography mission using shuttle laser altimeter , 2003 .

[14]  John D. Vona,et al.  Vegetation height estimation from Shuttle Radar Topography Mission and National Elevation Datasets , 2004 .

[15]  A. Braun,et al.  Calibration of the shuttle radar topography mission X-SAR instrument using a synthetic altimetry data model , 2002 .

[16]  P. Pizor.  Principles of Geographical Information Systems for Land Resources Assessment. , 1987 .

[17]  P. Lohmann,et al.  QUALITY ASSESSMENT AND VALIDATION OF DIGITAL SURFACE MODELS DERIVED FROM THE SHUTTLE RADAR TOPOGRAPHY MISSION (SRTM) , 2000 .

[18]  Marian Werner,et al.  Shuttle Radar Topography Mission (SRTM) Mission Overview , 2001 .

[19]  A. Roth,et al.  The shuttle radar topography mission—a new class of digital elevation models acquired by spaceborne radar , 2003 .

[20]  Guoqing Sun,et al.  Validation of surface height from shuttle radar topography mission using shuttle laser altimeter , 2003 .