Air-LUSI: A robotic telescope design for lunar spectral measurements

Cataford, Andrew; Gadsden, S. Andrew; Turpie, Kevin R.

doi:10.1016/j.asr.2020.02.014

Cited by 6 publications

(7 citation statements)

References 13 publications

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“…The Autonomous Robotic Telescope Mount Instrument Subsystem (ARTEMIS) was originally commissioned as a Master's project in the Intelligent and Cognitive Engineering (ICE) Lab at the University of Guelph. 10 The complexity of developing this mission-critical system required the establishment of numerous design constraints, which are categorized below in Table 1. In summary, a corrosion-resistant airworthy telescope mount, with at minimum two degrees of freedom (DOFs), designed according to an extremely conservative margin of safety and employing a Computer Vision (CV) based feedback control system is required for the mission.…”

Section: Artemismentioning

confidence: 99%

“…A thorough account of the ARTEMIS' mechanical and control system design is available in. 10 The tracking performance of ARTEMIS is evaluated by the pixel offset in the CV camera frame between a predetermined pixel setpoint (that which aligns the Moon with the center of the telescope) and the center of the Moon. It was experimentally determined that the particular camera/lens combination provides 0.053 • of angular resolution per pixel.…”

Section: Environmentalmentioning

confidence: 99%

“…It was experimentally determined that the particular camera/lens combination provides 0.053 • of angular resolution per pixel. 10 The absolute pixel offset, obtained from the squared sum of squares of x and y pixel offsets, is then converted to an angular displacement for comparison with the 0.5 • mission constraint. Pixel error data is recorded at the control loop rate of 30 Hz.…”

Section: Environmentalmentioning

confidence: 99%

See 2 more Smart Citations

Towards a second-generation robotic telescope mount for the air-LUSI instrument

Newton,

McCafferty-Leroux,

Gadsden

et al. 2023

Sensors and Systems for Space Applications XVI

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Earth observation satellites, such as those responsible for monitoring the effects of climate change, require rigorous calibration protocols to account for on-orbit sensor degradation. An increasingly dependable method to address this issue uses the Moon as a reference light source for in-situ calibration. The airborne lunar spectral irradiance (air-LUSI) mission aims to improve the utility of the Moon as an on-orbit calibration target for remote sensing instruments, by tying the currently accepted lunar model to the SI and establishing lunar irradiance on an absolute scale. To this end, air-LUSI collects SI-traceable measurements of lunar irradiance at visible to nearinfrared wavelengths with unprecedented accuracy. A non-imaging telescope is flown at an altitude of 21 km, aboard NASA's high-altitude ER-2 aircraft, which places the instrument above 95% of the Earth's atmosphere for clean, minimally obstructed lunar spectra. To fix the optical axis on the Moon during flight, an autonomous control system is required to compensate for aircraft motion and track the Moon across its celestial transit. In this paper, we present an overview of the robotic subsystem used to track the Moon on more than ten high-altitude flights, and the valuable lessons learned from those campaigns. From this insight, a preliminary design for a second-generation robotic telescope mount is presented. Referred to as the HAAMR, it will supplant the current robotics system on future air-LUSI Operational Flight Campaigns, with the nearest field deployment slated for January 2024. We show how this new system is poised to offer a more reliable, accurate, and responsive platform for the air-LUSI instrument to continue collecting data that will ultimately help to improve our understanding of the Earth's climate.

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Section: Artemismentioning

confidence: 99%

Section: Environmentalmentioning

confidence: 99%

Section: Environmentalmentioning

confidence: 99%

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Towards a second-generation robotic telescope mount for the air-LUSI instrument

Newton,

McCafferty-Leroux,

Gadsden

et al. 2023

Sensors and Systems for Space Applications XVI

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“…The team at McMaster University developed the ARTEMIS to use a double gimbal, endowing the telescope with degrees of freedom in azimuth and elevation. 7 Linear actuators were used as a variable length linkages to incite rotation about each degree of freedom. [8][9][10] The ARTEMIS control system uses a simplified approach to control the pointing of the telescope when compared to other inertially stabilized systems that are commonly implemented for target tracking.…”

Section: Introductionmentioning

confidence: 99%

Air-LUSI: an autonomous robotic telescope for high-altitude lunar spectral irradiance measurements

Newton

Maxwell

Gadsden

et al. 2022

Advanced Optics for Imaging Applications: UV Through LWIR VII

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The airborne lunar spectral irradiance (air-LUSI) mission is an inter-agency partnership between the US National Aeronautics and Space Administration and the US National Institute of Standards and Technology. Air-LUSI aims to make SI-traceable measurements of lunar spectral irradiance at visible to near-infrared wavelengths with unprecedented accuracy. To minimize uncertainty, lunar spectra are acquired above 90 % of the Earth's atmosphere aboard NASA's Earth Resources aircraft, a civilian descendant of the U-2 spy plane. The data collected by the air-LUSI instrument is poised to improve upon current lunar calibrations of Earth observing satellites.The air-LUSI team recently completed their Operational Flight Campaign in Palmdale, California in March 2022. In addition to the Engineering Flight Campaign of August 2018 and the Demonstration Flight Campaign of November 2019, the air-LUSI instrument has been successfully deployed on over ten lunar spectral measurement flights at altitudes of roughly 21 km. This paper presents the simplified double gimbal design that was capable of recently tracking the Moon with a root mean square tracking error of less than 0.1 • .

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“…To date, the air-LUSI instrument has successfully completed two separate field campaigns [10]. The 2018 Engineering Flight Campaign aimed to prove the engineering efficacy of the device, ensuring safe electromechanical integration with the aircraft, as well as providing a baseline for evaluating the target tracking capabilities [8].…”

mentioning

confidence: 99%

Air-LUSI

Newton¹,

Maxwell²,

Gadsden³

et al. 2020

Progress in Canadian Mechanical Engineering. Volume 3

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The air-LUSI (airborne LUnar Spectral Irradiance) mission is a program jointly sponsored by the National Aeronautics and Space Administration (NASA) and the National Institute of Standards and Technology (NIST) that aims to establish the moon as an absolute calibration source for space-based radiometric sensors. Integrated with NASA's highaltitude aircraft, the ER-2, the air-LUSI instrument completed a successful set of so-called Engineering Flights in August of 2018, capturing some of the clearest lunar spectra data sets to date. In response to challenges encountered during the Engineering Flight Campaign, all subsystems, including the Irradiance Instrument Subsystem (IRIS), the Autonomous, Robotic Telescope Mount Instrument Subsystem (ARTEMIS), and High-altitude ER-2 Adaptation (HERA) received upgrades to improve instrument reliability and performance ahead of the 2019 Demonstration Flight Campaign. This paper provides an overview of the project, outlines the upgrades and improvements made to the Autonomous Robotic Telescope Mount Instrument Subsystem (ARTEMIS) by the team at the University of Guelph, and presents the robotic tracking performance data from both the 2018 Engineering and 2019 Demonstration Flight Campaigns.

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Air-LUSI: A robotic telescope design for lunar spectral measurements

Cited by 6 publications

References 13 publications

Towards a second-generation robotic telescope mount for the air-LUSI instrument

Towards a second-generation robotic telescope mount for the air-LUSI instrument

Air-LUSI: an autonomous robotic telescope for high-altitude lunar spectral irradiance measurements

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