Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements
The co-located normalized radar backscatter cross section measurements from the Global Precipitation Measurement (GPM) Ku/Ka-band dual-frequency precipitation radar (DPR) and sea surface wind; wave and temperature observations from the National Data Buoy Center (NDBC) moored buoys are used to analyz...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2019-03-01
|
| Series: | Remote Sensing |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-4292/11/7/754 |
| _version_ | 1819110807025221632 |
|---|---|
| author | Qiushuang Yan Jie Zhang Chenqing Fan Junmin Meng |
| author_facet | Qiushuang Yan Jie Zhang Chenqing Fan Junmin Meng |
| author_sort | Qiushuang Yan |
| collection | DOAJ |
| description | The co-located normalized radar backscatter cross section measurements from the Global Precipitation Measurement (GPM) Ku/Ka-band dual-frequency precipitation radar (DPR) and sea surface wind; wave and temperature observations from the National Data Buoy Center (NDBC) moored buoys are used to analyze the dependence and sensitivity of Ku- and Ka-band backscatter on surface conditions at low-incidence angles. Then the potential for inverting wind and wave parameters directly from low-incidence <i>σ</i><sup>0</sup> measurements is discussed. The results show that the KaPR <i>σ</i><sup>0</sup> is more sensitive to surface conditions than the KuPR <i>σ</i><sup>0</sup> overall. Nevertheless; both the KuPR <i>σ</i><sup>0</sup> and KaPR <i>σ</i><sup>0</sup> are strongly correlated with wind speed (<i>U</i><sub>10</sub>) and average wave steepness (<i>δ<sub>a</sub></i>) with the exception of specific transitional incidence angles. Moreover, <i>U</i><sub>10</sub> and <i>δ<sub>a</sub></i> could be retrieved from pointwise <i>σ</i><sup>0</sup> near nadir and near 18°. Near 18°; wind direction information is needed as the effect of wind direction on <i>σ</i><sup>0</sup> becomes increasingly significant with incidence angle. To improve the performance of <i>U</i><sub>10</sub> retrieval; especially for low <i>U</i><sub>10</sub>; auxiliary <i>δ<sub>a</sub></i> information would be most helpful; and sea surface temperature is better taken into account. Other wave parameters; such as significant wave height; wave period and wave age; are partly correlated with <i>σ</i><sup>0</sup>. It is generally more difficult to retrieve those parameters directly from pointwise <i>σ</i><sup>0</sup>. For the retrieval of those wave parameters; various auxiliary information is needed. Wind direction and wave direction cannot be retrieved from pointwise <i>σ</i><sup>0</sup>. |
| first_indexed | 2024-12-22T03:47:35Z |
| format | Article |
| id | doaj.art-58aa8bc925fb4bcfbc699c65a59097d3 |
| institution | Directory Open Access Journal |
| issn | 2072-4292 |
| language | English |
| last_indexed | 2024-12-22T03:47:35Z |
| publishDate | 2019-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj.art-58aa8bc925fb4bcfbc699c65a59097d32022-12-21T18:40:06ZengMDPI AGRemote Sensing2072-42922019-03-0111775410.3390/rs11070754rs11070754Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar MeasurementsQiushuang Yan0Jie Zhang1Chenqing Fan2Junmin Meng3First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, ChinaFirst Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, ChinaFirst Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, ChinaFirst Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, ChinaThe co-located normalized radar backscatter cross section measurements from the Global Precipitation Measurement (GPM) Ku/Ka-band dual-frequency precipitation radar (DPR) and sea surface wind; wave and temperature observations from the National Data Buoy Center (NDBC) moored buoys are used to analyze the dependence and sensitivity of Ku- and Ka-band backscatter on surface conditions at low-incidence angles. Then the potential for inverting wind and wave parameters directly from low-incidence <i>σ</i><sup>0</sup> measurements is discussed. The results show that the KaPR <i>σ</i><sup>0</sup> is more sensitive to surface conditions than the KuPR <i>σ</i><sup>0</sup> overall. Nevertheless; both the KuPR <i>σ</i><sup>0</sup> and KaPR <i>σ</i><sup>0</sup> are strongly correlated with wind speed (<i>U</i><sub>10</sub>) and average wave steepness (<i>δ<sub>a</sub></i>) with the exception of specific transitional incidence angles. Moreover, <i>U</i><sub>10</sub> and <i>δ<sub>a</sub></i> could be retrieved from pointwise <i>σ</i><sup>0</sup> near nadir and near 18°. Near 18°; wind direction information is needed as the effect of wind direction on <i>σ</i><sup>0</sup> becomes increasingly significant with incidence angle. To improve the performance of <i>U</i><sub>10</sub> retrieval; especially for low <i>U</i><sub>10</sub>; auxiliary <i>δ<sub>a</sub></i> information would be most helpful; and sea surface temperature is better taken into account. Other wave parameters; such as significant wave height; wave period and wave age; are partly correlated with <i>σ</i><sup>0</sup>. It is generally more difficult to retrieve those parameters directly from pointwise <i>σ</i><sup>0</sup>. For the retrieval of those wave parameters; various auxiliary information is needed. Wind direction and wave direction cannot be retrieved from pointwise <i>σ</i><sup>0</sup>.https://www.mdpi.com/2072-4292/11/7/754GPM DPR cross sectionlow-incidence remote sensingsea surfaceradar signal analysis |
| spellingShingle | Qiushuang Yan Jie Zhang Chenqing Fan Junmin Meng Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements Remote Sensing GPM DPR cross section low-incidence remote sensing sea surface radar signal analysis |
| title | Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements |
| title_full | Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements |
| title_fullStr | Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements |
| title_full_unstemmed | Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements |
| title_short | Analysis of Ku- and Ka-Band Sea Surface Backscattering Characteristics at Low-Incidence Angles Based on the GPM Dual-Frequency Precipitation Radar Measurements |
| title_sort | analysis of ku and ka band sea surface backscattering characteristics at low incidence angles based on the gpm dual frequency precipitation radar measurements |
| topic | GPM DPR cross section low-incidence remote sensing sea surface radar signal analysis |
| url | https://www.mdpi.com/2072-4292/11/7/754 |
| work_keys_str_mv | AT qiushuangyan analysisofkuandkabandseasurfacebackscatteringcharacteristicsatlowincidenceanglesbasedonthegpmdualfrequencyprecipitationradarmeasurements AT jiezhang analysisofkuandkabandseasurfacebackscatteringcharacteristicsatlowincidenceanglesbasedonthegpmdualfrequencyprecipitationradarmeasurements AT chenqingfan analysisofkuandkabandseasurfacebackscatteringcharacteristicsatlowincidenceanglesbasedonthegpmdualfrequencyprecipitationradarmeasurements AT junminmeng analysisofkuandkabandseasurfacebackscatteringcharacteristicsatlowincidenceanglesbasedonthegpmdualfrequencyprecipitationradarmeasurements |