Kohdetaso

Kohdetaso, meaning literally “target plane” in Finnish, is a term used in Finnish technical literature to denote a reference plane in an imaging, projection, or measurement system onto which the target or image is mapped. The concept describes the plane of interest where the imaging system forms or projects the target.

In optics and photography, the kohdetaso is often the image plane or sensor plane where the detected image ultimately resides. Focusing and optical design aim to place the image of the target onto this plane, so that measurements or visual representations are accurate and stable. The term is used to distinguish the plane from other planes in the optical path, such as object space or intermediate planes.

In surveying, metrology, and calibration work, the kohdetaso functions as a reference plane for aligning targets and for instrument calibration. By positioning a target on or in relation to this plane, engineers can relate measurements to a consistent geometric frame of reference.

In computer vision and photogrammetry, the concept is applied in the context of projecting 3D world points onto a 2D plane. When this projection occurs onto the kohdetaso, a planar homography can relate image coordinates to real-world coordinates on that plane.

See also: image plane, focal plane, sensor plane, projection, homography, calibration.