What type of imagery is referred to as ortho imagery?

Ortho imagery refers specifically to corrected top-down imagery that has been processed to remove distortions caused by camera tilt, terrain relief, and other factors. This process ensures that the imagery has a uniform scale and accurately represents the Earth’s surface, allowing for precise measurements and analysis. Unlike images captured from an angle or those that include multiple perspectives— which may present varying heights and orientations—ortho imagery provides a true overhead view, making it suitable for various applications in GIS, such as mapping, land use planning, and assessment.

This correction process typically involves techniques such as geometrical correction and triangulation, making ortho imagery distinct in its reliability and usability for spatial analysis. This characteristic is what makes it a foundational element in GIS work, where maintaining accuracy in spatial data is critical.