A self-supervised framework for space object behaviour characterisation

Groves, Ian and Campbell, Andrew John and Fernandes, James and Rodríguez, Diego Ramírez and Murray, Paul and Vasile, Massimiliano and Nockles, Victoria (2025) A self-supervised framework for space object behaviour characterisation. Other. arXiv. (https://doi.org/10.48550/arXiv.2504.06176)

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Abstract

Foundation Models, pre-trained on large unlabelled datasets before task-specific fine-tuning, are increasingly being applied to specialised domains. Recent examples include ClimaX for climate and Clay for satellite Earth observation, but a Foundation Model for Space Object Behavioural Analysis has not yet been developed. As orbital populations grow, automated methods for characterising space object behaviour are crucial for space safety. We present a Space Safety and Sustainability Foundation Model focusing on space object behavioural analysis using light curves (LCs). We implemented a Perceiver-Variational Autoencoder (VAE) architecture, pre-trained with self-supervised reconstruction and masked reconstruction on 227,000 LCs from the MMT-9 observatory. The VAE enables anomaly detection, motion prediction, and LC generation. We fine-tuned the model for anomaly detection & motion prediction using two independent LC simulators (CASSANDRA and GRIAL respectively), using CAD models of boxwing, Sentinel-3, SMOS, and Starlink platforms. Our pre-trained model achieved a reconstruction error of 0.01%, identifying potentially anomalous light curves through reconstruction difficulty. After fine-tuning, the model scored 88% and 82% accuracy, with 0.90 and 0.95 ROC AUC scores respectively in both anomaly detection and motion mode prediction (sun-pointing, spin, etc.). Analysis of high-confidence anomaly predictions on real data revealed distinct patterns including characteristic object profiles and satellite glinting. Here, we demonstrate how self-supervised learning can simultaneously enable anomaly detection, motion prediction, and synthetic data generation from rich representations learned in pre-training. Our work therefore supports space safety and sustainability through automated monitoring and simulation capabilities.

ORCID iDs

Groves, Ian, Campbell, Andrew John ORCID logoORCID: https://orcid.org/0000-0002-4439-3630, Fernandes, James, Rodríguez, Diego Ramírez, Murray, Paul ORCID logoORCID: https://orcid.org/0000-0002-6980-9276, Vasile, Massimiliano ORCID logoORCID: https://orcid.org/0000-0001-8302-6465 and Nockles, Victoria;