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Main Authors: Deng, Junwei, Xu, Chang, Ma, Jiaqi W., Jin, Ming, Liu, Chenghao, Bian, Jiang
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2601.19040
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author Deng, Junwei
Xu, Chang
Ma, Jiaqi W.
Jin, Ming
Liu, Chenghao
Bian, Jiang
author_facet Deng, Junwei
Xu, Chang
Ma, Jiaqi W.
Jin, Ming
Liu, Chenghao
Bian, Jiang
contents Time Series Foundation Models (TSFMs) are a powerful paradigm for time series analysis and are often enhanced by synthetic data augmentation to improve the training data quality. Existing augmentation methods, however, typically rely on heuristics and static paradigms. Motivated by dynamic data optimization, which shows that the contribution of samples varies across training stages, we propose OATS (Online Data Augmentation for Time Series Foundation Models), a principled strategy that generates synthetic data tailored to different training steps. OATS leverages valuable training samples as principled guiding signals and dynamically generates high-quality synthetic data conditioned on them. We further design a diffusion-based framework to produce realistic time series and introduce an explore-exploit mechanism to balance efficiency and effectiveness. Experiments on TSFMs demonstrate that OATS consistently outperforms regular training and yields substantial performance gains over static data augmentation baselines across six validation datasets and two TSFM architectures. The code is available at the link https://github.com/microsoft/TimeCraft.
format Preprint
id arxiv_https___arxiv_org_abs_2601_19040
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle OATS: Online Data Augmentation for Time Series Foundation Models
Deng, Junwei
Xu, Chang
Ma, Jiaqi W.
Jin, Ming
Liu, Chenghao
Bian, Jiang
Machine Learning
Time Series Foundation Models (TSFMs) are a powerful paradigm for time series analysis and are often enhanced by synthetic data augmentation to improve the training data quality. Existing augmentation methods, however, typically rely on heuristics and static paradigms. Motivated by dynamic data optimization, which shows that the contribution of samples varies across training stages, we propose OATS (Online Data Augmentation for Time Series Foundation Models), a principled strategy that generates synthetic data tailored to different training steps. OATS leverages valuable training samples as principled guiding signals and dynamically generates high-quality synthetic data conditioned on them. We further design a diffusion-based framework to produce realistic time series and introduce an explore-exploit mechanism to balance efficiency and effectiveness. Experiments on TSFMs demonstrate that OATS consistently outperforms regular training and yields substantial performance gains over static data augmentation baselines across six validation datasets and two TSFM architectures. The code is available at the link https://github.com/microsoft/TimeCraft.
title OATS: Online Data Augmentation for Time Series Foundation Models
topic Machine Learning
url https://arxiv.org/abs/2601.19040