By Andy Tomaswick March 13, 2025
CubeSats have a lot of advantages. They are small, inexpensive, and easily reproducible. But those advantages also come with significant disadvantages - they have trouble linking into broader constellations that allow them to be more effective at their observational or communication tasks. A team from the University of Albany thinks they might have solved that problem by using a customized calibration algorithm to ensure the right CubeSats link up together.
The system, called the Adaptive Calibration of CubeSat Radiometer Constellations (or ACCURACy), uses data from each of the CubeSats in a constellation. They pass along pertinent data, especially about their position and temperature. Thedecides which sets of CubeSats should be paired together for calibration and excludes ones that don't fit the right profile.
One crucial fact is that this algorithm only works for CubeSats with radiometers. Typically, these collect data on a range of the electromagnetic spectrum outside visible light, such as UV or IR, and many CubeSats already have them for various observational tasks. However, they have a weak point because they are extremely sensitive to thermal stress.
Fraser discusses fleets of satellites coordinated with each other.
Heat is not easy to dissipate in space, and CubeSats already have a relatively low thermal mass, meaning they can heat and cool much more quickly than other, larger satellites. There are some ways around this, such as using a tool called a blackbody target that allows an IR imager to calibrate to a known value, but CubeSats are too small to carry around the necessary thermal dissipation system.
Recently, another study looked at one potential solution to this problem—carrying a thermometer. More accurately, it looked at CubeSats that carried a thermistor—a type of temperature detector—right next to their radiometer and then adjusted the output of that radiometer based on the reading of the thermistor.
ACCURACy, at it's core, takes that concept another step further. It assumes that every Cubesat in the constellation has a thermistor on board, and it collects temperature data about the state of each radiometer. It then calculates distances between the CubeSats, looks at similarities in those temperatures, and attempts to combine them to reflect a reasonable calibration approximation most accurately.
Discussion on how constellations of CubeSats can be used for unique astronomy.
Credit - IEEE Microwave Theory and Technology Society YouTube Channel
Many considerations go into that calculation, and the researchers decided to prove it by creating a model in MATLAB, which included fake data representing real position and temperature readings. Other considerations, like orbital paths or the age of the spacecraft, could also impact it. The program also compared ACCURACy's calibration with a method known as state-of-the-art (SOTA) calibration and showed a clear superiority of ACCURACy's approach.
As the research paper's conclusion states, plenty of work remains. They are planning to use calibration data from MIT's TROPICS mission, which is meant to study cyclones, and further analyze data from IceCube, which was already used in some of the preliminary simulations.
Eventually, ACCURACy or a similar algorithm could help coordinate massive fleets of CubeSats, all calibrated toward the same goal. That is when we will finally start to see even more of the benefits of CubeSat constellations.
Learn More:
Bradburn et al. - ACCURACy: A Novel Calibration Framework for CubeSat Radiometer Constellations
UT - SpIRIT CubeSat Demonstrates a Operational Gamma and X-Ray Detector
UT - A Pair of CubeSats Using Ground Penetrating Radar Could Map The Interior of Near Earth Asteroids
UT - NASA CubeSat Discovers New Radiation Belts After Intense Solar Storm