Information about a feature on the Earth's surface that is collected in the field. In remote sensing, the process of acquiring ground truth data is referred to as "ground truthing."
Alert: Global Health Learning will go offline after May 31, 2025. You can use our Print feature to download course content for your reference. Log in, go to a course, click the Print link in the right sidebar. The course pages will be rolled together in one HTML page. You can copy/paste into a Google doc or save as HTML.