The series of lessons that comprise this unit are intended to take students from direct observations of their schoolyard to interpretation of air photographs of their schoolyard. As steps along the way, students create a three dimensional model of the school site based on their initial field observations. They then make an "air photo" of this model and analyze land cover types fro this. In this way, they learn first hand what an air photo is, and begin to develop the skills of land cover classification and quantification from something that they've created themselves. Finally, they analyze a real air photo of their school site, identify land cover types, try to quantify these, and ground truth them through field reconnaissance.