date: 2024-07-19T07:37:29Z pdf:PDFVersion: 1.7 pdf:docinfo:title: Sea Ice Detection from GNSS-R Data Based on Local Linear Embedding xmp:CreatorTool: LaTeX with hyperref Keywords: delay-Doppler maps (DDMs); Global Navigation Satellite System-Reflectometry (GNSS-R); local linear embedding (LLE); sea ice detection access_permission:modify_annotations: true access_permission:can_print_degraded: true subject: Sea ice plays a critical role in the Earth?s climate system, and its variations affect ecosystem stability. This study introduces a novel method for detecting sea ice in the Arctic Ocean using bidirectional radar reflections from the Global Navigation Satellite System (GNSS). Utilizing delay-Doppler maps (DDM) from the UK TechDemoSat-1 (TDS-1) satellite mission and surface data from the U.S. National Oceanic and Atmospheric Administration (NOAA), we employ the local linear embedding (LLE) algorithm for feature extraction. This approach notably reduces training costs and enhances real-time performance, while maintaining a high accuracy and robust noise immunity level. Focusing on the region above 70 north latitude throughout 2018, we aimed to distinguish between sea ice and seawater. The extracted DDM features via LLE are input into a support vector machine (SVM) for classification. The results indicate that our method achieves an accuracy of over 99% for selected low-noise data and a monthly average accuracy of 92.74% for data containing noise, while the CNN method has a monthly average accuracy of only 77.31% for noisy data. A comparative analysis between the LLE-SVM approach and the convolutional neural network (CNN) method demonstrated the superior anti-interference capabilities of the former. Additionally, the impact of the sea ice melting period on detection accuracy was analyzed. dc:creator: Yuan Hu, Xifan Hua, Qingyun Yan, Wei Liu, Zhihao Jiang and Jens Wickert dcterms:created: 2024-07-19T07:34:48Z Last-Modified: 2024-07-19T07:37:29Z dcterms:modified: 2024-07-19T07:37:29Z dc:format: application/pdf; version=1.7 title: Sea Ice Detection from GNSS-R Data Based on Local Linear Embedding Last-Save-Date: 2024-07-19T07:37:29Z pdf:docinfo:creator_tool: LaTeX with hyperref access_permission:fill_in_form: true pdf:docinfo:keywords: delay-Doppler maps (DDMs); Global Navigation Satellite System-Reflectometry (GNSS-R); local linear embedding (LLE); sea ice detection pdf:docinfo:modified: 2024-07-19T07:37:29Z meta:save-date: 2024-07-19T07:37:29Z pdf:encrypted: false dc:title: Sea Ice Detection from GNSS-R Data Based on Local Linear Embedding modified: 2024-07-19T07:37:29Z cp:subject: Sea ice plays a critical role in the Earth?s climate system, and its variations affect ecosystem stability. This study introduces a novel method for detecting sea ice in the Arctic Ocean using bidirectional radar reflections from the Global Navigation Satellite System (GNSS). Utilizing delay-Doppler maps (DDM) from the UK TechDemoSat-1 (TDS-1) satellite mission and surface data from the U.S. National Oceanic and Atmospheric Administration (NOAA), we employ the local linear embedding (LLE) algorithm for feature extraction. This approach notably reduces training costs and enhances real-time performance, while maintaining a high accuracy and robust noise immunity level. Focusing on the region above 70 north latitude throughout 2018, we aimed to distinguish between sea ice and seawater. The extracted DDM features via LLE are input into a support vector machine (SVM) for classification. The results indicate that our method achieves an accuracy of over 99% for selected low-noise data and a monthly average accuracy of 92.74% for data containing noise, while the CNN method has a monthly average accuracy of only 77.31% for noisy data. A comparative analysis between the LLE-SVM approach and the convolutional neural network (CNN) method demonstrated the superior anti-interference capabilities of the former. Additionally, the impact of the sea ice melting period on detection accuracy was analyzed. pdf:docinfo:subject: Sea ice plays a critical role in the Earth?s climate system, and its variations affect ecosystem stability. This study introduces a novel method for detecting sea ice in the Arctic Ocean using bidirectional radar reflections from the Global Navigation Satellite System (GNSS). Utilizing delay-Doppler maps (DDM) from the UK TechDemoSat-1 (TDS-1) satellite mission and surface data from the U.S. National Oceanic and Atmospheric Administration (NOAA), we employ the local linear embedding (LLE) algorithm for feature extraction. This approach notably reduces training costs and enhances real-time performance, while maintaining a high accuracy and robust noise immunity level. Focusing on the region above 70 north latitude throughout 2018, we aimed to distinguish between sea ice and seawater. The extracted DDM features via LLE are input into a support vector machine (SVM) for classification. The results indicate that our method achieves an accuracy of over 99% for selected low-noise data and a monthly average accuracy of 92.74% for data containing noise, while the CNN method has a monthly average accuracy of only 77.31% for noisy data. A comparative analysis between the LLE-SVM approach and the convolutional neural network (CNN) method demonstrated the superior anti-interference capabilities of the former. Additionally, the impact of the sea ice melting period on detection accuracy was analyzed. Content-Type: application/pdf pdf:docinfo:creator: Yuan Hu, Xifan Hua, Qingyun Yan, Wei Liu, Zhihao Jiang and Jens Wickert X-Parsed-By: org.apache.tika.parser.DefaultParser creator: Yuan Hu, Xifan Hua, Qingyun Yan, Wei Liu, Zhihao Jiang and Jens Wickert meta:author: Yuan Hu, Xifan Hua, Qingyun Yan, Wei Liu, Zhihao Jiang and Jens Wickert dc:subject: delay-Doppler maps (DDMs); Global Navigation Satellite System-Reflectometry (GNSS-R); local linear embedding (LLE); sea ice detection meta:creation-date: 2024-07-19T07:34:48Z created: Fri Jul 19 09:34:48 CEST 2024 access_permission:extract_for_accessibility: true access_permission:assemble_document: true xmpTPg:NPages: 18 Creation-Date: 2024-07-19T07:34:48Z access_permission:extract_content: true access_permission:can_print: true meta:keyword: delay-Doppler maps (DDMs); Global Navigation Satellite System-Reflectometry (GNSS-R); local linear embedding (LLE); sea ice detection Author: Yuan Hu, Xifan Hua, Qingyun Yan, Wei Liu, Zhihao Jiang and Jens Wickert producer: pdfTeX-1.40.25 access_permission:can_modify: true pdf:docinfo:producer: pdfTeX-1.40.25 pdf:docinfo:created: 2024-07-19T07:34:48Z