Session
Weekend Session 3: Science/Mission Payloads - Research & Academia I
Location
Utah State University, Logan, UT
Abstract
Applications in agriculture, land-cover change, and vegetation phenology, to name a few, would benefit from more frequent high-quality remote sensing data. However, ”Landsat-class” satellites are too expensive for such applications. Therefore, there is a need to augment larger Earth observation satellites with nanosatellites that use scientific-grade imaging instruments. This paper presents the design for the scientific-grade multispectral imager Theia. It is designed for a 5% radiometric accuracy at a ground sampling distance of 33 m at a 650 km orbit while keeping the modulation transfer function above 0.13 at the Nyquist frequency. The camera has reflective optics with an aluminium optomechanical design to mitigate stress from thermal expansion. Furthermore, the optical path is covered with a mix of black anodization and Acktar Magic Black to suppress stray-light. The sCMOS sensor is back-side illuminated to increase the radio metric quality of the instrument. Furthermore, the imager has a post-launch calibration system for continuous monitoring of the instrument’s quality. The performance is achieved while fitting inside 0.6 CubeSat Units and weighing about 600 g. However, a trade-off between the modulation transfer function and radio metric quality is presented. Such an imager, when deployed on numerous nanosatellites, can enable new kinds of missions that are otherwise too costly. The project is funded by the European Space Agency.
Design of a Scientific-Grade Multispectral Imager for Nanosatellites
Utah State University, Logan, UT
Applications in agriculture, land-cover change, and vegetation phenology, to name a few, would benefit from more frequent high-quality remote sensing data. However, ”Landsat-class” satellites are too expensive for such applications. Therefore, there is a need to augment larger Earth observation satellites with nanosatellites that use scientific-grade imaging instruments. This paper presents the design for the scientific-grade multispectral imager Theia. It is designed for a 5% radiometric accuracy at a ground sampling distance of 33 m at a 650 km orbit while keeping the modulation transfer function above 0.13 at the Nyquist frequency. The camera has reflective optics with an aluminium optomechanical design to mitigate stress from thermal expansion. Furthermore, the optical path is covered with a mix of black anodization and Acktar Magic Black to suppress stray-light. The sCMOS sensor is back-side illuminated to increase the radio metric quality of the instrument. Furthermore, the imager has a post-launch calibration system for continuous monitoring of the instrument’s quality. The performance is achieved while fitting inside 0.6 CubeSat Units and weighing about 600 g. However, a trade-off between the modulation transfer function and radio metric quality is presented. Such an imager, when deployed on numerous nanosatellites, can enable new kinds of missions that are otherwise too costly. The project is funded by the European Space Agency.
