Online Spectral Density Estimation

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Kazi, Shahriar Hasnat, Adams, Niall, Cohen, Edward A. K.
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908653376765952
author Kazi, Shahriar Hasnat
Adams, Niall
Cohen, Edward A. K.
author_facet Kazi, Shahriar Hasnat
Adams, Niall
Cohen, Edward A. K.
contents This paper develops the first online algorithms for estimating the spectral density function -- a fundamental object of interest in time series analysis -- that satisfies the three core requirements of streaming inference: fixed memory, fixed computational complexity, and temporal adaptivity. Our method builds on the concept of forgetting factors, allowing the estimator to adapt to gradual or abrupt changes in the data-generating process without prior knowledge of its dynamics. We introduce a novel online forgetting-factor periodogram and show that, under stationarity, it asymptotically recovers the properties of its offline counterpart. Leveraging this, we construct an online Whittle estimator, and further develop an adaptive online spectral estimator that dynamically tunes its forgetting factor using the Whittle likelihood as a loss. Through extensive simulation studies and an application to ocean drifter velocity data, we demonstrate the method's ability to track time-varying spectral properties in real-time with strong empirical performance.
format Preprint
id arxiv_https___arxiv_org_abs_2511_11296
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Online Spectral Density Estimation
Kazi, Shahriar Hasnat
Adams, Niall
Cohen, Edward A. K.
Methodology
62L12 (Primary) 62M05, 62M15 (Secondary)
This paper develops the first online algorithms for estimating the spectral density function -- a fundamental object of interest in time series analysis -- that satisfies the three core requirements of streaming inference: fixed memory, fixed computational complexity, and temporal adaptivity. Our method builds on the concept of forgetting factors, allowing the estimator to adapt to gradual or abrupt changes in the data-generating process without prior knowledge of its dynamics. We introduce a novel online forgetting-factor periodogram and show that, under stationarity, it asymptotically recovers the properties of its offline counterpart. Leveraging this, we construct an online Whittle estimator, and further develop an adaptive online spectral estimator that dynamically tunes its forgetting factor using the Whittle likelihood as a loss. Through extensive simulation studies and an application to ocean drifter velocity data, we demonstrate the method's ability to track time-varying spectral properties in real-time with strong empirical performance.
title Online Spectral Density Estimation
topic Methodology
62L12 (Primary) 62M05, 62M15 (Secondary)
url https://arxiv.org/abs/2511.11296