DEM TRAINING
(DIGITAL ELEVATION MODEL)
STEP 1
• OPEN GIS
STEP 2
• LOAD IMAGE FILE INTO GIS
• X:\Projects\Miscellaneous\Training
DEM\HTA_2012_LIDAR_Surface\HTA_2012_LI
DAR_Surface
• 2012_surface_HTA_50cm.img
STEP 3
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CREATE A NEW SHAPEFILE
NAME IT NEW_POINT
FEATURE TYPE IS POINT
EDIT COORDINATE SYSTEM
PROJECTED COORDINATE SYSTEMS
UTM, WGS 1984, NORTHERN HEMISPHERE,
ZONE 32 NORTH
STEP 4
• DROP A POINT ON THE MAP (IT DOES NOT
MATTER WHERE)
• SELECT NEW SHAPEFILE AND START EDITING
• THEN SELECT THE CREATE FEATURES ICON IN
THE EDITOR TOOLBAR, SELECT YOUR
SHAPEFILE AND DROP YOUR POINT
• STOP EDITING
STEP 5
• BUFFER YOUR POINT
• ARC TOOLBOX, ANALYSIS TOOLS, PROXIMITY, BUFFER
• MAKE IT 0.15 MILES
STEP 6
• EXTRACT BY MASK
• ARC TOOLBOX, SPATIAL ANALYST TOOLS, EXTRACTION
• NEXT TURN OFF ALL OTHER LAYERS EXCETP YOUR MASK
STEP 7
• RASTER TO POINT
• ARC TOOLBOX, CONVERSON TOOLS, FROM RASTER, RASTER
TO POINT (THIS MAY TAKE A MINUET)
STEP 8
• ADD FIELD
• ARC TOOLBOX, DATA MANAGEMENT TOOLS,
FIELDS, ADD FIELDS
STEP 9
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SELECT FIRST 100 POINTS ONLY
TABLE OPTIONS, SELECT BY ATTRIBUTES
DOUBLE CLICK “OBJECT ID”
THEN SELECT LESS THAN 100
<100, APPLY
STEP 10
• CALCULATE GEOMETRY
• IN THE ATTRIBUTE TABLE RIGHT CLICK ON THE
NEW FIELD, AND SELECT CALCULATE
GEOMETRY
FINAL STEP
• EXPORT FEATURE ATTRIBUTE TO ASC2
• ARC TOOLBOX, SPATIAL STATISTICS TOOLS, UTILITIES, EXPORT
FEATURE ATTRIBUTE TO ASC2
• SET DELIMITER TO COMMA
OPEN FILE
• MAKE SURE TO OPEN THE FILE WITH
NOTEPAD