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ASTER GDEM 2 README

ADVANCED SPACEBORNE THERMAL EMISSION AND REFLECTION RADIOMETER (ASTER) GLOBAL DIGITAL ELEVATION MODEL (GDEM) VERSION 2

October 2011

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EXECUTIVE SUMMARY
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) is concurrently distributed from the Ministry of Economy, Trade, and Industry (METI) Earth RemoteSensing Data Analysis Center (ERSDAC) in Japan and the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS) Data Information System (EOSDIS) Land Processes (LP) Distributed Active Archive Center (DAAC) in the United States. Version 2 is produced with the same gridding and tile structure as Version 1. Improvements over version 1 include the use of additional scenes toimprove coverage, a smaller correlation kernel to yield higher spatial resolution, and an improved water mask.

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CONTENTS
Executive Summary ................................................................................................................. ii Contents................................................................................................................................... 3 List of Tables and Figures ....................................................................................................... 3 Introduction .............................................................................................................................. 4 ASTER GDEM Characteristics................................................................................................ 5 Basic GDEM Characteristics .................................................................................................. 5 GDEM Package ..................................................................................................................... 5 QA File Description................................................................................................................ 6 GDEM Validation Summary ..................................................................................................... 9 Disclaimer................................................................................................................................. 9 Use Constraints....................................................................................................................... 9 User Services ..........................................................................................................................10 Acronym List ...........................................................................................................................11

LIST OF TABLES AND FIGURES
Figure 1 ASTER GDEM File Structure....................................................................................... 6

Table 1 ASTER GDEM Characteristics ...................................................................................... 5 Table 2 Anomaly Replacement Sources .................................................................................... 8

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INTRODUCTION
The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)on the National Aeronautic and Space Administration (NASA) spacecraft Terra is capable of collecting in-track stereo using nadir- and aft- looking near infrared cameras. Since 2001, these stereo pairs have been used to produce single-scene (60- x 60-kilometer (km)) digital elevation models (DEM) having vertical (root-mean-squared-error) accuracies generally between 10- and 25-meters (m). On June29, 2009, NASA and the Ministry of Economy, Trade, and Industry (METI) of Japan released a Global Digital Elevation Model (GDEM) to users worldwide at no charge as a contribution to the Global Earth Observing System of Systems. This “Version 1” ASTER GDEM (GDEM 1.0) was compiled from over 1.2 million scene-based DEMs covering land surface between 83 degrees (°) north (N) and 83° south (S)...