Design of Compact Long-Slit Wynne-Offner Spectrometer for Hyperspectral Remote Sensing

This paper focuses on the compact long-slit Wynne-Offner imaging spectrometer suitable for wide-swath high-resolution remote sensing applications. Through tracing the chief ray, astigmatism of Wynne-Offner spectrometer was theoretically analyzed, and the expression of astigmatism was deduced for any object point. It was pointed that the anastigmatic region of Wynne-Offner spectrometer is much larger than that of the classic Offner spectrometer. Steps for designing a Wynne-Offner spectrometer are shown and two examples of long-slit Wynne-Offner spectrometers are given. One works in the wavelength range of 0.5–1.0 μm and another works in 1.0–2.5 μm. The image quality of both spectrometers was close to the diffraction limit, and distortions were negligible. Such Wynne-Offner spectrometers have the advantages of long slit, compact structure, and high imaging quality.