Georeferencing and GoogleEarth Francisco Olivera, Ph.D., P.E. Celso Ferreira Department of Civil Engineering Texas 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 Images e.g.: Brazos County Aerial Photos from 1940

Georeferencing Concepts Source: ESRI Help

Georeferencing Concepts Source: ESRI Help

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:

Preparing the data in ArcGis Exchanging data: Keyhole Markup Language (KML) is an XML-based language schemaXML language 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 KML In GoogleEarth Open KML

Examples – Watershed delineation

Demo: Visualizing data using GoogleEarth Data available from: Dr. Olivera home page / Geomatics in Civil Engineering (CVEN 423) / Spring /home.htm

Questions ?