Exercise #4 - Ground Truth Data Collection:

1. Online resources

2. Field work

Ground Truth

• Jargon term for surface observations.

– On-site gathering of data that characterizes surface

– Aids in interpretation of imagery

• Field observations - in situ spectral measurements, aerial

photography, descriptive reports, and maps.

• Most common reasons for conducting field activities

are;

– select training sites prior to supervised classification

– identify key classes after unsupervised classification.

• If logistics or circumstances limit field operations,

then use aerial photography, maps, literature

research, etc.

• In practice, to specify training sites generally means

integrating the following sources of information:

direct observations, photo documentation, a variety

of maps, personal familiarity.

Right mouse clickon map and choose‘save picture as’

Latitude 34.1024Longitude -117.7227

mapslive.com

itouchmap.com

Go to Terraserver website

List of images: Urban Areas 3/29/2004 Aerial Photo 6/1/1994 Topo Map 7/1/1978

Click on info buttonto get cross hairs

Right Click and choose ‘Save image as’

Sample Table

Sample Pictures

GPS apps

longitude latitude

-117.824478 34.0581

Can send files to yourself

GPS appsNice pics

GPS appsEmail coordinates plus map

Latitude: 34.058244 Longitude: -117.824593Map url