View
218
Download
4
Embed Size (px)
Citation preview
Georeferencing and GoogleEarth
Francisco Olivera, Ph.D., P.E.Celso Ferreira
Department of Civil EngineeringTexas A&M University
Overview
Georeferencing using ArcGIS
Visualizing data in Google Earth
Georeferencing:
Acquiring a digital image
Importing images in ArcGIS
Defining control points
Resampling the image
Acquiring Imagese.g.: Brazos County Aerial Photos from 1940
Georeferencing Concepts
Source: ESRI Help
Georeferencing Concepts
Source: ESRI Help
Real World Coordinates
Original Image Raster
Georeferencing GoogleEarth Images
Find control points in Image
Get coordinates for each point
Use Georeferencing toolbar for adjusting the image
Demo: Georeferencing Images using ArcGIS
Exercise Outline:
Goal: Find Reed Arena geographical location using a 1940 aerial photograph
• Load the georeferenced layers
• Load the 1940 Image
• Georeference the image
• Delineate a polygon around Reed
Arena
GoogleEarth:
GoogleEarth:Preparing the data in ArcGis
Exchanging data:Keyhole Markup Language (KML) is an XML-based language schema
Generating KML files from ArcGis
Importing KML files in GoogleEarth
Preparing the data
General geoprocessing procedures
Identify, clip, intersect, union…
Make sure to “clean up the data” and select appropriate area
Generating KML
Conversion Tools>>To KML>>Layer to KML
Importing KMLIn GoogleEarth Open KML
Examples – Watershed delineation
Examples – Watershed delineation
Demo: Visualizing data using GoogleEarth
Data available from:Dr. Olivera home page / Geomatics in Civil Engineering
(CVEN 423) / Spring 2009https://ceprofs.civil.tamu.edu/folivera/CVEN423/
Spring2009/home.htm
Questions ?