In order to find trace quickly, this paper introduces a real-time method with a set of equidistant linear array sensor to detect relative cross state and absolute position between trace and tracker.

An auto measuring system of aerial camera lens is presented, which substitutes linear array CCD sensor for reading microscope to measure the focus of aerial camera lens.

The general theory and methods from geometrical optics to measure the dimension of an object were applied to design a diameter measuring system, which was based on a linear array image sensor.