PURPOSE: To elevate and simplify a tracking performance, by constituting an optical homing device of an optical system having spherical aberration, a two- dimensional image sensor and a picture signal processor, and positively utilizing the spherical aberration.

CONSTITUTION: This device is constituted of an optical system 1 having different focal distances on the concentric circle from space areas S1WS3, a two-dimensional CCD sensor 2 and a picture signal processor 3. In this optical system, the focal distances are varied as f1Wf3 in accordance with a distance variation from the center, and the sensor 2 is placed in a position of f3. Accordingly, when an object is in infinity, the object and the background are at an equal distance, and an area of S3 condenses. When the object approaches, the condensing part is varied as S2→S1. On the other hand, the background is condensed by the S3 part, therefore, when the object has approached, the spherical aberration has an effect of one kind of space frequency adaptive filter. Therefore, the tracking property can be elevated by utilizing the spherical aberration and equalizing a performance variation of a detector due to a variation of a distance reaching the object.