A multispectrum fish-eye lens for rice canopy detecting

In this paper, a fish-eye lens used for detecting rice canopy has been presented. This is a small lens with broad spectrum detection. The lens is composed of two groups, with three changeable optical filters between them. The filters can be changed automatically by stepper motor. All the data can be analyzed immediately by the laptop computer. The first sample lens shows its good performance of image quality and portability for outdoor operation.