Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning

Abstract This study introduces two innovative methods—Three-frequency pseudorange combination (TFPC) and Three-frequency carrier phase combination (TFCPC)—for estimating soil moisture using GNSS-IR technology. Unlike traditional methods that require separating direct and reflected signals, these app...

Full description

Saved in:
Bibliographic Details
Main Authors: Yintao Liu, Chao Ren, Hongjuan Shao
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Scientific Reports
Subjects:
Online Access:https://doi.org/10.1038/s41598-025-09029-4
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849399726794866688
author Yintao Liu
Chao Ren
Hongjuan Shao
author_facet Yintao Liu
Chao Ren
Hongjuan Shao
author_sort Yintao Liu
collection DOAJ
description Abstract This study introduces two innovative methods—Three-frequency pseudorange combination (TFPC) and Three-frequency carrier phase combination (TFCPC)—for estimating soil moisture using GNSS-IR technology. Unlike traditional methods that require separating direct and reflected signals, these approaches leverage carrier phase and pseudorange multipath errors to improve accuracy. The new methods eliminate the impact of geometrical factors and atmospheric delays. By applying minimum covariance determinant (MCD) and moving average filter (MAF), the study effectively detects and corrects outliers in delay phases, enhancing the quality of the data. Using data from the Plate Boundary Observatory (PBO) H2O project, the study finds that combining corrected delay phases from multiple satellites improves correlations between estimated and actual soil moisture values. The TFPC method achieves correlation coefficients of 0.82 and 0.87 with multivariate linear regression (MLR) and radial basis function neural network (RBFNN) models, while the TFCPC method yields even better results at 0.85 and 0.91, respectively. These findings represent a significant advancement in high-precision soil moisture estimation, offering valuable implications for applications in agriculture, weather forecasting, and environmental monitoring.
format Article
id doaj-art-e1faadcb7a1742ca845c4b17865eafdd
institution Kabale University
issn 2045-2322
language English
publishDate 2025-07-01
publisher Nature Portfolio
record_format Article
series Scientific Reports
spelling doaj-art-e1faadcb7a1742ca845c4b17865eafdd2025-08-20T03:38:15ZengNature PortfolioScientific Reports2045-23222025-07-0115111910.1038/s41598-025-09029-4Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learningYintao Liu0Chao Ren1Hongjuan Shao2College of Geomatics and Geoinformation, Guilin University of TechnologyCollege of Geomatics and Geoinformation , Guilin University of TechnologyCollege of Physics and Electronic Information Engineering, Guilin University of TechnologyAbstract This study introduces two innovative methods—Three-frequency pseudorange combination (TFPC) and Three-frequency carrier phase combination (TFCPC)—for estimating soil moisture using GNSS-IR technology. Unlike traditional methods that require separating direct and reflected signals, these approaches leverage carrier phase and pseudorange multipath errors to improve accuracy. The new methods eliminate the impact of geometrical factors and atmospheric delays. By applying minimum covariance determinant (MCD) and moving average filter (MAF), the study effectively detects and corrects outliers in delay phases, enhancing the quality of the data. Using data from the Plate Boundary Observatory (PBO) H2O project, the study finds that combining corrected delay phases from multiple satellites improves correlations between estimated and actual soil moisture values. The TFPC method achieves correlation coefficients of 0.82 and 0.87 with multivariate linear regression (MLR) and radial basis function neural network (RBFNN) models, while the TFCPC method yields even better results at 0.85 and 0.91, respectively. These findings represent a significant advancement in high-precision soil moisture estimation, offering valuable implications for applications in agriculture, weather forecasting, and environmental monitoring.https://doi.org/10.1038/s41598-025-09029-4GNSS-IRSoil moistureThree-frequency pseudorange combinationThree-frequency carrier phase combinationRobust estimateMachine learning
spellingShingle Yintao Liu
Chao Ren
Hongjuan Shao
Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning
Scientific Reports
GNSS-IR
Soil moisture
Three-frequency pseudorange combination
Three-frequency carrier phase combination
Robust estimate
Machine learning
title Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning
title_full Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning
title_fullStr Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning
title_full_unstemmed Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning
title_short Study on soil moisture estimation using a three-frequency combination of observations integrated with robust estimation and machine learning
title_sort study on soil moisture estimation using a three frequency combination of observations integrated with robust estimation and machine learning
topic GNSS-IR
Soil moisture
Three-frequency pseudorange combination
Three-frequency carrier phase combination
Robust estimate
Machine learning
url https://doi.org/10.1038/s41598-025-09029-4
work_keys_str_mv AT yintaoliu studyonsoilmoistureestimationusingathreefrequencycombinationofobservationsintegratedwithrobustestimationandmachinelearning
AT chaoren studyonsoilmoistureestimationusingathreefrequencycombinationofobservationsintegratedwithrobustestimationandmachinelearning
AT hongjuanshao studyonsoilmoistureestimationusingathreefrequencycombinationofobservationsintegratedwithrobustestimationandmachinelearning