Detecting changes in mixed-sampling rate data sequences

Different environmental variables are often monitored using different sampling rates; examples include half-hourly weather station measurements, daily (Formula presented.) data, and six-day satellite data. Further when researchers want to combine the data into a single analysis this often requires d...

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Bibliographic Details
Published in:Environmetrics
Main Authors: Lowther, Aaron, Killick, Rebecca, Eckley, Idris
Format: Article in Journal/Newspaper
Language:English
Published: 2023
Subjects:
Online Access:https://eprints.lancs.ac.uk/id/eprint/175217/
https://eprints.lancs.ac.uk/id/eprint/175217/1/draft_ol_black.pdf
Description
Summary:Different environmental variables are often monitored using different sampling rates; examples include half-hourly weather station measurements, daily (Formula presented.) data, and six-day satellite data. Further when researchers want to combine the data into a single analysis this often requires data aggregation or down-scaling. When one is seeking to identify changes within multivariate data, the aggregation and/or down-scaling processes obscure the changes we seek. In this article, we propose a novel changepoint detection algorithm which can analyze multiple time series for co-occurring changepoints with potentially different sampling rates, without requiring preprocessing to a standard sampling scale. We demonstrate the algorithm on synthetic data before providing an example identifying simultaneous changes in multiple variables at a location on the Greenland ice sheet using synthetic aperture radar and weather station data.