Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data
Fengyun-3C (FY-3C) is a Global Navigation Satellite Systems (GNSS) Radio Occultation (RO) mission founded which was by China on 23 September 2013. In this study, under a specific temporal and spatial domain, we systematically compare FY-3C refractivity profiles with Constellation Observing System fo...
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doaj-64684f1d0bba4ceb838635596dfc15472021-06-01T00:31:20ZengMDPI AGRemote Sensing2072-42922021-05-01131980198010.3390/rs13101980Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation DataWeiwei Chen0Yongliang Xiong1Xinzhong Li2Ban Zhao3Rui Zhang4Shaoguang Xu5Faculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFaculty of Geosciences and Environmental Engineering, Southwest Jiaotong University, Chengdu 611756, ChinaFengyun-3C (FY-3C) is a Global Navigation Satellite Systems (GNSS) Radio Occultation (RO) mission founded which was by China on 23 September 2013. In this study, under a specific temporal and spatial domain, we systematically compare FY-3C refractivity profiles with Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) refractivity profiles for the year 2015. The COSMIC profiles used in this study contain reflections, as identified in the Radio Occultation Meteorology Satellite Application Facility (ROM SAF) flag database. From 0 to 25 km altitude, the mean biases and relative standard deviations of the comparisons between FY-3C and COSMIC are less than 1% and 2% when COSMIC profiles present reflected signals. Radio holographic analysis is used to visualize and identify the spectra of FY-3C-reflected signals in the time-frequency domain. It is confirmed that the reflected signals in the lower troposphere and near the surface can be tracked by an FY-3C receiver. Further, most of the FY-3C events that matched with COSMIC reflected events show reflection patterns at a lower height, especially above the ocean’s surface. Under Bouguer’s rule and spherical symmetry assumptions, we reconstructed the reflected bending angle models by Abel transformation, which are valuable for reducing N-bias in the ducting layer. Three examples of FY-3C events show that the reflected bending branch is near the surface. Overall, the reflected signal of FY-3C could be used as a supplementary data portion for FY-3C atmospheric products.https://www.mdpi.com/2072-4292/13/10/1980Fengyun-3Cradio occultationquality analysisreflection |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Weiwei Chen Yongliang Xiong Xinzhong Li Ban Zhao Rui Zhang Shaoguang Xu |
spellingShingle |
Weiwei Chen Yongliang Xiong Xinzhong Li Ban Zhao Rui Zhang Shaoguang Xu Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data Remote Sensing Fengyun-3C radio occultation quality analysis reflection |
author_facet |
Weiwei Chen Yongliang Xiong Xinzhong Li Ban Zhao Rui Zhang Shaoguang Xu |
author_sort |
Weiwei Chen |
title |
Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data |
title_short |
Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data |
title_full |
Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data |
title_fullStr |
Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data |
title_full_unstemmed |
Preliminary Validation of Surface Reflections from Fengyun-3C Radio Occultation Data |
title_sort |
preliminary validation of surface reflections from fengyun-3c radio occultation data |
publisher |
MDPI AG |
series |
Remote Sensing |
issn |
2072-4292 |
publishDate |
2021-05-01 |
description |
Fengyun-3C (FY-3C) is a Global Navigation Satellite Systems (GNSS) Radio Occultation (RO) mission founded which was by China on 23 September 2013. In this study, under a specific temporal and spatial domain, we systematically compare FY-3C refractivity profiles with Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC) refractivity profiles for the year 2015. The COSMIC profiles used in this study contain reflections, as identified in the Radio Occultation Meteorology Satellite Application Facility (ROM SAF) flag database. From 0 to 25 km altitude, the mean biases and relative standard deviations of the comparisons between FY-3C and COSMIC are less than 1% and 2% when COSMIC profiles present reflected signals. Radio holographic analysis is used to visualize and identify the spectra of FY-3C-reflected signals in the time-frequency domain. It is confirmed that the reflected signals in the lower troposphere and near the surface can be tracked by an FY-3C receiver. Further, most of the FY-3C events that matched with COSMIC reflected events show reflection patterns at a lower height, especially above the ocean’s surface. Under Bouguer’s rule and spherical symmetry assumptions, we reconstructed the reflected bending angle models by Abel transformation, which are valuable for reducing N-bias in the ducting layer. Three examples of FY-3C events show that the reflected bending branch is near the surface. Overall, the reflected signal of FY-3C could be used as a supplementary data portion for FY-3C atmospheric products. |
topic |
Fengyun-3C radio occultation quality analysis reflection |
url |
https://www.mdpi.com/2072-4292/13/10/1980 |
work_keys_str_mv |
AT weiweichen preliminaryvalidationofsurfacereflectionsfromfengyun3cradiooccultationdata AT yongliangxiong preliminaryvalidationofsurfacereflectionsfromfengyun3cradiooccultationdata AT xinzhongli preliminaryvalidationofsurfacereflectionsfromfengyun3cradiooccultationdata AT banzhao preliminaryvalidationofsurfacereflectionsfromfengyun3cradiooccultationdata AT ruizhang preliminaryvalidationofsurfacereflectionsfromfengyun3cradiooccultationdata AT shaoguangxu preliminaryvalidationofsurfacereflectionsfromfengyun3cradiooccultationdata |
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