Abstract: This work presents a new approach to anomaly detection and localization in synthetic aperture radar imagery (SAR), expanding upon the existing patch distribution modeling framework (PaDiM). We introduce the adaptive cosine estimator (ACE) detection statistic. PaDiM uses the Mahalanobis distance at inference, an unbounded metric. ACE instead uses the cosine similarity metric, providing bounded anomaly detection scores. The proposed method is evaluated across multiple SAR datasets, with performance metrics including the area under the receiver operating curve (AUROC) at the image and pixel level, aiming for increased performance in anomaly detection and localization of SAR imagery.
Publication date: April 2025
Link: https://arxiv.org/abs/2504.08049
Citation: A. Ibarra and J. Peeples, “Patch distribution modeling framework learnable adaptive cosine estimator (PaDiM-LACE) for anomaly detection in synthetic aperture radar imagery,” in Algorithms for Synthetic Aperture Radar Imagery XXXII, International Society for Optics and Photonics (SPIE), 2025, in Press.