An optical system for detecting vegetation with the use of a single image sensor, such as a charge coupled device (CCD) camera is provided by optical elements which project separate red and near infrared (NIR) images onto the CCD camera. The camera then can supply output signals representative of the...http://www.google.de/patents/US5621460?utm_source=gb-gplus-sharePatent US5621460 - Optical differentiation between plants and background utilizing a single CCD camera
