Download DEM and D8 User Guide - Geoscience Australia

CONTENTS
CHAPTER 1
INTRODUCTION..........................................................................................................................2
Geoscience Australia .................................................................................................................................3
The Fenner School of Environment and Society, ANU..............................................................................3
Summary of the 9 Second DEM and Flow Direction Grid..........................................................................4
CHAPTER 2
THE DEVELOPMENT OF THE 9 SECOND DEM.......................................................................5
Early National Digital Elevation Models .....................................................................................................6
9 Second DEM Version 1 ...........................................................................................................................6
9 Second DEM Version 2 ...........................................................................................................................7
9 Second DEM Version 3 ...........................................................................................................................8
CHAPTER 3
ABOUT DEM’S AND FLOW DIRECTION GRIDS ......................................................................9
What is a DEM? ...................................................................................................................................... 10
What is a Flow Direction Grid?................................................................................................................ 11
CHAPTER 4
PRODUCT INFORMATION...................................................................................................... 12
Coordinate Systems and Grid Properties................................................................................................ 13
DVD Contents ......................................................................................................................................... 13
Formats ................................................................................................................................................... 13
CHAPTER 5
ESSENTIAL CHARACTERISTICS OF THE DEM ................................................................... 15
Physical Configuration of the DEM ......................................................................................................... 16
Source Data Summary ............................................................................................................................ 17
Map Sheet Effects ................................................................................................................................... 18
The ANUDEM Gridding Algorithm........................................................................................................... 19
Accuracy Estimates................................................................................................................................. 19
CHAPTER 6
BUILDING THE DEM-9S VERSION 3 AND D8-9S ................................................................. 23
The Revised Source Data ....................................................................................................................... 24
The Digital Elevation Model Production Process .................................................................................... 31
The Flow Direction Grid Production Process .......................................................................................... 33
Quality Assurance ................................................................................................................................... 34
CHAPTER 7
ANUDEM .................................................................................................................................. 35
Introduction to ANUDEM ......................................................................................................................... 36
Drainage Enforcement Algorithm ............................................................................................................ 37
Outline of Program Structure................................................................................................................... 38
APPENDIX A
ACKNOWLEDGMENTS ......................................................................................................... 40
APPENDIX B
REFERENCES ........................................................................................................................ 41
APPENDIX C
9 SECOND DEM PRODUCTION TILE COORDINATES ....................................................... 43
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