Remote sensing in the present context refers to the collection of data and information about the earth’s surface and lower atmosphere using aerial sensors. Sensors can be mounted on vehicles that fly near to earth (e.g. airplanes, balloons and drones), or far from earth such as aboard satellites. Data collected are typically recordings of electromagnetic energy, either through active or passive means. Passive remote sensing measures the sun’s energy as it reflects off of objects, whereas active remote sensors emit their own energy to measure reflectance.

This guide is distinguished from the ‘Aerial Photography – Historic’ guide in that it addresses contemporary aerial photography that is typically georeferenced and orthrectified (i.e. orthoimagery), as part of its collection and preprocessing. In contrast to most historic aerial photography, orthoimagery is suitable for incorporation into geographic information systems to be used for spatial analysis without any preparation or manipulation.