Optical Design of Near-Infrared Telescope for CubeSat Remote-Sensing Instrument with InGaAs Image Sensor

The remote-sensing instrument (RSI) applications are essential to capture images within specific spectral bands. And, to classify the targeted information, it is crucial to choose the appropriate atmospheric windows based on the apparent spectral zone. That helps to overcome challenges related to complicated physical limitations to achieve the crucial applications of RSI. This study aims to design a near-infrared (NIR) telescope equipped with an indium gallium arsenide (InGaAs) image sensor for a 2U CubeSat RSI. The telescope has been designed to operate within specific spectral ranges within the NIR spectrum. The estimated modulation transfer function (MTF) of the NIR telescope exhibits a performance greater than 0.25 per 10 $\mu$m pixel pitch (50lp/mm) of the InGaAs image sensor, resulting in a ground sampling distance (GSD) of 16 m and a swath width of20.48 km when the NIR telescope is positioned at a flight height of 480 km.