Abstract
With the proliferation of CubeSats operating commercial off-the-shelf (COTS) instruments, it is necessary to assess the operational and performance limitations inherent with these reduced-cost systems, to understand applicability to specific mission areas. One of these limitations, as it pertains to the weather and environmental remote sensing mission area, is the limited satellite volume to house on-board calibrators (OCs) which characterize the instrument’s calibration while in orbit. Since most, if not all, Visible/Infrared payloads on CubeSats do not implement OCs, the instrument’s precision and stability can be significantly degraded as compared to their more expensive counterparts, such as the National Oceanic and Atmospheric Administration (NOAA) Visible Infrared Imaging Radiometer Suite (VIIRS) or the United States Geological Survey (USGS) Landsat 8 instruments. To improve instrument calibration for these systems, radiometrically stable and well-known target sources can be used as on-orbit vicarious calibration targets, such as homogeneous Earth scenes and the Moon.
The Aerospace Corporation’s Weather Remote Sensing Systems (WRemSS) Office implementation of the RObotic Lunar Observatory (ROLO) model was applied for on-orbit radiometric assessment of Aerospace’s CubeSat Multispectral Observing System (CUMULOS) on NASA JPL’s Integrated Solar Array and Reflectarray Antenna (ISARA) CubeSat. ISARA is a 3U CubeSat launched 12 Nov. 2017 on Cygnus Orbital ATK CRS OA-8 with CUMULOS taking up ~1U of volume. CUMULOS was designed as a compact payload for testing low-cost commercial cameras for weather and Earth environmental monitoring. It can measure surface temperature, detect fires and other environmental hotspots, take cloud cover pictures, and provide nighttime lights imaging by using three compact cameras: a visible wavelength camera, a short-wavelength infrared camera, and a long-wavelength infrared system microbolometer camera. The payload consists of three optics and sensor pairs: a panchromatic, visible CMOS camera, a short-wavelength infrared InGaAs camera, and a long-wavelength infrared microbolometer camera. This paper we will describe the CUMULOS instrument, present our radiometric stability assessment of the visible CMOS camera using the ROLO model, trending of dark field subtraction, anomalies, and lessons learned.
Using Lunar Observations to Radiometrically Assess the CUMULOS' Visible Camera
With the proliferation of CubeSats operating commercial off-the-shelf (COTS) instruments, it is necessary to assess the operational and performance limitations inherent with these reduced-cost systems, to understand applicability to specific mission areas. One of these limitations, as it pertains to the weather and environmental remote sensing mission area, is the limited satellite volume to house on-board calibrators (OCs) which characterize the instrument’s calibration while in orbit. Since most, if not all, Visible/Infrared payloads on CubeSats do not implement OCs, the instrument’s precision and stability can be significantly degraded as compared to their more expensive counterparts, such as the National Oceanic and Atmospheric Administration (NOAA) Visible Infrared Imaging Radiometer Suite (VIIRS) or the United States Geological Survey (USGS) Landsat 8 instruments. To improve instrument calibration for these systems, radiometrically stable and well-known target sources can be used as on-orbit vicarious calibration targets, such as homogeneous Earth scenes and the Moon.
The Aerospace Corporation’s Weather Remote Sensing Systems (WRemSS) Office implementation of the RObotic Lunar Observatory (ROLO) model was applied for on-orbit radiometric assessment of Aerospace’s CubeSat Multispectral Observing System (CUMULOS) on NASA JPL’s Integrated Solar Array and Reflectarray Antenna (ISARA) CubeSat. ISARA is a 3U CubeSat launched 12 Nov. 2017 on Cygnus Orbital ATK CRS OA-8 with CUMULOS taking up ~1U of volume. CUMULOS was designed as a compact payload for testing low-cost commercial cameras for weather and Earth environmental monitoring. It can measure surface temperature, detect fires and other environmental hotspots, take cloud cover pictures, and provide nighttime lights imaging by using three compact cameras: a visible wavelength camera, a short-wavelength infrared camera, and a long-wavelength infrared system microbolometer camera. The payload consists of three optics and sensor pairs: a panchromatic, visible CMOS camera, a short-wavelength infrared InGaAs camera, and a long-wavelength infrared microbolometer camera. This paper we will describe the CUMULOS instrument, present our radiometric stability assessment of the visible CMOS camera using the ROLO model, trending of dark field subtraction, anomalies, and lessons learned.