Accessing the Data
Aerial imagery is overhead images of the landscape. It is stored in raster files and has no other data attached to it.
To add aerial imagery as a backdrop to your map, you must first determine what specific indexed image you need.
- Add O:\Cataloged\Local\Greater HoustonRegion\HoustonGalvestonAreaCouncil as a new folder connection.
- Drag the file lambert_grid.shp to your map and navigate to your area (using streets as a reference).
- Once you find the grid squares that overlay your area, use the Explore tool to find their 4-digit LAMBERT numbers. Take note of these numbers.
- To remove the Lambert Grid, right click the layer name in the Contents Pane and select Remove.
Now you know the ID numbers of the files you will be picking.
All of the aerial imagery is on mass storage drives in the GDC Head’s office, so you will need to ask a staff member for them. Imagery of the Houston area is available for 2010, 2008, and more.
Once you have your drive plugged in (USB and power cord), you will have to connect to the E:\ drive.
Each file should be available in several formats:
- TIFFs are full resolution, with file sizes of around 300 MB, and should only be used for the imagery alone.
- MrSID files are compressed (30 MB) and optimized for GIS programs, so they should be used if you plan on using the image in ArcGIS.
Files are also available in 1-feet or 6-inch resolutions (refers to the width of a pixel), although 6 inch are only available for downtown Houston, Greenway Plaza, Rice and other high interest areas.
5. Drag the file(s) you want into your ArcGIS Pro document.