AbstractAbstract
The Polar Radiant Energy in the Far-Infrared Experiment (PREFIRE) is a low-cost CubeSat mission comprising two 6U CubeSats in separate sun-synchronous orbits that continuously measure spectral emissions up to 54
µ
m and provide ongoing, time-lapsed observations of the polar processes that modulate them. PREFIRE fulfilled its prime mission between 1 August 2024 and 30 April 2025, during which time each CubeSat,
PREFIRE-SAT1
and
PREFIRE-SAT2
, regularly resampled itself (“self-intersections”) and the other satellite (“SAT1–SAT2 intersections”). Since PREFIRE intersections will reveal the spectral signatures of the processes that modulate thermal emission from the Arctic and Antarctic, this paper introduces methods to identify PREFIRE resampling and establishes the spatial and temporal records of subdaily PREFIRE intersections from 1 August 2024 to 30 April 2025. Our results indicate that about 76% of self-intersections and over 80% of SAT1–SAT2 intersections occur poleward of 60° latitude. Self-intersections form discrete, time-invariant latitude–temporal bands with time scales that become progressively shorter toward higher latitudes. Conversely, SAT1–SAT2 intersections are dynamic, varying in step with the increasing offset in orbital altitude between satellites, and they exhibit broader time differences between crossovers than self-intersections. Our results further suggest that the second PREFIRE CubeSat nearly quadruples the number of possible daily intersections and SAT1–SAT2 intersections yield twice as many latitude–temporal bands as self-intersections, underscoring the utility of a configuration featuring multiple CubeSats.
