Casey Demars, Tech7; Corey Packard, ThermoAnalytics, Inc.; David Tyler, The Tech7 Company; Christopher Rodgers, Tech7
Keywords: Thermal, Infrared, Modeling, Simulation, Longwave, Space Domain Awareness, SDA
Abstract:
Thermal imaging phenomenology for space-domain awareness has benefits over conventional electro-optical imaging alone, potentially providing additional information about the operational state of target satellites. LWIR sensors also provide capability for daytime imaging, as demonstrated with the 3.6 meter telescope at the AMOS site on Maui, Hawaii. Detailed radiometric simulations with 3-D synthetic satellite objects can provide a valuable forward model for estimation problems; however, due to the complex computations required to simulate radiative transfer, development of satellite-focused thermal modeling and simulation has lagged similar tools developed for visible and SWIR sensors. Here, we demonstrate the use of MuSES to generate external temperature distributions for synthetic targets. MuSES simulates transient solar loading, thermal radiation from earth and to space, as well as conductive and radiative transport from internal heat sources such as electronics. Additionally, solar panels and battery cell charging and discharging can be realistically incorporated via coupled thermal/electric multi-physics solvers in MuSES. By attributing the synthetic target with the emissive properties of the materials at each surface facet, we can convert model temperature distributions to radiance maps. These maps allow radiometric signal levels in mid- and long-wave IR wavebands to be generated by simulating telescope and sensor effects. Using these tools, we demonstrate observation of the change in target surface temperature distributions and infrared signal levels due to an internal power source. We evaluate temperature distributions of a 3U CubeSat under different operating loads for multiple orbits, including low-earth and geostationary orbits in and out of eclipse. We also demonstrate the incorporation of thermal models into a high-fidelity radiometric environment for generating multi-spectral light curves.
Date of Conference: September 19-22, 2023
Track: Satellite Characterization