A novel concept for hyperspectral remote sensing

Frequency modulation (FM) reticles can be used to create hyperspectral imaging systems that operate simultaneously from the ultraviolet to the far infrared (IR) region of the optical spectrum. If an optical material that transmits the bands to be imaged can be produced, an imager can be constructed using FM reticle techniques that will image all bands simultaneously. An example of a broadband material is barium fluoride. A hyperspectral reticle imager could consist of the following components: a barium fluoride entrance window, reflective imaging optics, a metal reticle, a beam splitting filter to separate the visible and IR energy, barium fluoride or reflective condensing optics, two diffraction gratings, a silicon linear array for the UV to near IR, and an InSb/HgCdTe sandwich linear array for the middle and far IR. A system diagram is shown.