Multipurpose spectral imager

A small spectral imaging system is presented that images static or moving o bjects simultaneously as a function of wavelength. The main physical princi ple is outlined and demonstrated. The instrument is capable of resolving bo th spectral and spatial information from targets throughout the entire visi ble region. The spectral domain has a bandpass of 12 Angstrom. One can achi eve the spatial domain by rotating the system's front mirror with a high-re solution stepper motor. The spatial resolution range from millimeters to se veral meters depends mainly on the front optics used and whether the target is fixed (static) or movable relative to the instrument. Different applica tions and examples are explored, including outdoor landscapes, industrial f ish-related targets, and ground-level objects observed in the more traditio nal way from an airborne carrier (remote sensing). Through the examples, we found that the instrument correctly classifies whether a shrimp is peeled and whether it can disclose the spectral and spatial microcharacteristics o f targets such as a fish nematode (parasite). In the macroregime, we were a ble to distinguish a marine vessel from the surrounding sea and sky. A stud y of the directional spectral albedo from clouds, mountains, snow cover, an d vegetation has also been included. With the airborne experiment, the imag er successfully classified snow cover, leads, and new and raft ed ice, as s een from 10.000 ft (3.048 m). (C) 2000 Optical Society of America. OCIS cod es: 000.2190, 120.4570, 120.6200, 300.6550.