Analysis of tidal river height monitoring using low-cost GNSS interferometric reflectometry

Analysis of tidal river height monitoring using low-cost GNSS interferometric reflectometry | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Analysis of tidal river height monitoring using low-cost GNSS interferometric reflectometry Arizal Bawasir, Mokhamad Nur Cahyadi, Syachrul Arief, Putra Maulida, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6201950/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Global Navigation Satellite System (GNSS) signal exploration is advancing rapidly, and one of the latest techniques is GNSS interferometric reflectometry (GNSS-IR). This method uses multipath signals to measure the vertical distance from the reflecting surface to a geodetic antenna or receiver. Traditional scientific-grade GNSS instruments are costly, limiting their widespread use in environmental monitoring. To address this issue, we employed low-cost GNSS devices to monitor water levels at PT Garam Pamekasan using the GNSS-IR method. In this study, we tested two antenna configurations: vertically (zenith-looking) and obliquely toward the river (horizon-looking). By leveraging signal-to-noise ratio (SNR) observations, we were able to estimate water surface height with increased precision. The comparison of multipath signal characteristics revealed that the oblique antenna setup amplified the SNR amplitude, improving data quality and accuracy compared to conventional tide gauge observations. The oblique antenna showed a higher average Peak-to-Noise Ratio (PNR) of 4.52 compared to 3.95 for the upright antenna, indicating a higher quality signal. Comparisons with measurements taken using conventional tide gauges reveal that the oblique antenna produced a lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE), measuring 8.201 cm and 6.691 cm, respectively, compared to 13.894 cm and 11.438 cm for the upright antenna. The oblique antenna also demonstrated a stronger correlation with the tide gauge data, with a correlation coefficient (ρ) of 0.9837, surpassing the upright antenna’s value of 0.9615. The Van de Casteele test revealed fewer residuals and increased accuracy for the oblique antenna. Tide predictions showed 30% higher accuracy for the oblique antenna, with an RMSE of 10.130 cm compared to 14.064 cm for the upright antenna. Tidal predictions showed better performance with the oblique antenna, correlating with higher data quality and accuracy. Thus, our findings suggest that low-cost GNSS devices, particularly with an oblique antenna setup, are promising tools for GNSS-IR monitoring in narrow water bodies, providing reliable and accurate environmental data. Low-cost GNSS-IR signal-to-noise ratio periodogram antenna configuration river water level Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6201950","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":441520629,"identity":"b1b842ea-0698-48d3-9052-02ec236f1d14","order_by":0,"name":"Arizal Bawasir","email":"","orcid":"","institution":"Institut Teknologi Sepuluh Nopember","correspondingAuthor":false,"prefix":"","firstName":"Arizal","middleName":"","lastName":"Bawasir","suffix":""},{"id":441520631,"identity":"f70d4fd5-624d-4234-9209-c0f500ae093e","order_by":1,"name":"Mokhamad Nur 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This method uses multipath signals to measure the vertical distance from the reflecting surface to a geodetic antenna or receiver. Traditional scientific-grade GNSS instruments are costly, limiting their widespread use in environmental monitoring. To address this issue, we employed low-cost GNSS devices to monitor water levels at PT Garam Pamekasan using the GNSS-IR method. In this study, we tested two antenna configurations: vertically (zenith-looking) and obliquely toward the river (horizon-looking). By leveraging signal-to-noise ratio (SNR) observations, we were able to estimate water surface height with increased precision. The comparison of multipath signal characteristics revealed that the oblique antenna setup amplified the SNR amplitude, improving data quality and accuracy compared to conventional tide gauge observations. The oblique antenna showed a higher average Peak-to-Noise Ratio (PNR) of 4.52 compared to 3.95 for the upright antenna, indicating a higher quality signal. Comparisons with measurements taken using conventional tide gauges reveal that the oblique antenna produced a lower Root Mean Square Error (RMSE) and Mean Absolute Error (MAE), measuring 8.201 cm and 6.691 cm, respectively, compared to 13.894 cm and 11.438 cm for the upright antenna. The oblique antenna also demonstrated a stronger correlation with the tide gauge data, with a correlation coefficient (ρ) of 0.9837, surpassing the upright antenna\u0026rsquo;s value of 0.9615. The Van de Casteele test revealed fewer residuals and increased accuracy for the oblique antenna. Tide predictions showed 30% higher accuracy for the oblique antenna, with an RMSE of 10.130 cm compared to 14.064 cm for the upright antenna. Tidal predictions showed better performance with the oblique antenna, correlating with higher data quality and accuracy. Thus, our findings suggest that low-cost GNSS devices, particularly with an oblique antenna setup, are promising tools for GNSS-IR monitoring in narrow water bodies, providing reliable and accurate environmental data.\u003c/p\u003e","manuscriptTitle":"Analysis of tidal river height monitoring using low-cost GNSS interferometric reflectometry","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-24 10:24:48","doi":"10.21203/rs.3.rs-6201950/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"23137e27-6168-4078-b477-2c50b875bcf6","owner":[],"postedDate":"April 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-05-12T02:38:41+00:00","versionOfRecord":[],"versionCreatedAt":"2025-04-24 10:24:48","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6201950","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6201950","identity":"rs-6201950","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}