Analysis of COSMIC-2 radio occultation observations and atmospheric profiles
-
Abstract:
[Objectives] COSMIC-2 constellation, as the follow-on mission of COSMIC (Constellation Observing System for Meteorology Ionosphere and Climate), has refined the radio occultation (RO) payloads with multi-GNSS signals support and high-gain beam-forming RO antennas, which will improve both the quantity and quality of the RO observations. [Methods] In this research, we focused on the input observations and output profiles of the RO retrieval, evaluating the raw observations from both precise orbit determination (POD) and RO antennas, and accessing the atmospheric profiles using ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis products as reference. [Results] The results show that the L1 signal-to-noise ratio (SNR) on COSMIC-2 POD antennas were mostly above 45dB, and the corresponding pseudo-range multipath standard deviation errors were between 0.2m and 0.4m. The SNR values on RO antenna were significantly improved from less than 700v/v on COSMIC to 1200v/v on COSMIC-2, and both the GLONASS and GPS RO profiles show good consistency with ECMWF re-analysis products. [Conclusions] It can be concluded that the updated COSMIC-2 RO payloads not only increasing the profile number, and also the quality of RO profiles had been significantly improved with high-gain antennas, which will provide important observations for atmospheric scientific research.
-
Keywords:
- COSMIC-2 /
- radio occultation retrieval /
- atmospheric profile /
- quality analysis
-
-
[1] . Ware R, Rocken C, Solheim F, et al. GPS Sounding of the Atmosphere from Low Earth Orbit:Preliminary Results[J]. Bulletin of the American Meteorological Society, 1996, 77(1):19-40.
[2] . Rocken C, Anthes R, Exner M, et al. Analysis and validation of GPS/MET data in the neutral atmosphere[J]. Journal of Geophysical Research Atmospheres. 1997, 102(D25):29849-29866.
[3] . Schmidt T, Heise S, Wickert J, et al. GPS radio occultation with CHAMP and SAC-C:global monitoring of thermal tropopause parameters[J]. Atmospheric Chemistry & Physics, 2005, 5(6):1473-1488.
[4] . Wickert J, Beyerle G, Koenig R, et al. GPS radio occultation with CHAMP and GRACE:A first look at a new and promising satellite configuration for global atmospheric sounding[J]. Annales Geophysicae, 2005, 23(3):653-658.
[5] . Ho S, Anthes R, Ao C, et al. The COSMIC/FORMOSAT-3 Radio Occultation Mission after 12 Years:Accomplishments, Remaining Challenges, and Potential Impacts of COSMIC-2[J]. Bulletin of the American Meteorological Society. 2020, 101(7):E1107-E1136.
[6] . Gorbunov M, Irisov V, Rocken C. The Influence of the Signal-to-Noise Ratio upon Radio Occultation Retrievals[J]. Remote Sensing. 2022, 14(12):2742.
[7] . Schreiner W, Weiss J, Anthes R, et al. COSMIC-2 Radio Occultation Constellation:First Results[J]. Geophysical Research Letters, 2020, 47(4), e2019GL086841.
[8] . Cao C, Wang W, Lynch E, et al. Simultaneous Radio Occultation for Intersatellite Comparison of Bending Angles toward More Accurate Atmospheric Sounding[J]. Journal of Atmospheric and Oceanic Technology, 2020. 37(12):2307-2320.
[9] . Chen Y, Shao X, Cao C, et al. Simultaneous Radio Occultation Predictions for Inter-Satellite Comparison of Bending Angle Profiles from COSMIC-2 and GeoOptics[J]. Remote Sensing. 2021, 13(18):3644.
[10] . Anthes R, Sjoberg J, Feng X, et al. Comparison of COSMIC and COSMIC-2 Radio Occultation Refractivity and Bending Angle Uncertainties in August 2006 and 2021[J]. Atmosphere. 2022, 13(5):790.
[11] . Adhikari L, Ho S, Zhou X. Inverting COSMIC-2 Phase Data to Bending Angle and Refractivity Profiles Using the Full Spectrum Inversion Method[J]. Remote Sensing,2021,13(9):1793.
[12] . Ho S, Zhou X, Shao X, et al. Initial Assessment of the COSMIC-2/FORMOSAT-7 Neutral Atmosphere Data Quality in NESDIS/STAR Using In Situ and Satellite Data[J]. Remote Sensing, 2020, 12(24):4099.
[13] . Wang Borui, Liu Xiaoyang, Wang Jiuke. Assessment of COSMIC Radio Occultation Retrieval Product[J]. Acta Scientiarum Naturalium Universitatis Pekinensis, 2013, 49(2):241-251(王伯睿, 刘晓阳, 王久珂. COSMIC掩星反演数据质量分析[J]. 北京大学学报(自然科学版). 2013, 49(2):241-251) [14] . Xu Xiaohua, Wang Haihong. Comparative Study on the Accuracy of GPS Occultation Profiles in Different Seasons[J]. Geomatics and Information Science of Wuhan University, 2010, 35(6):639-643(徐晓华, 汪海洪. 不同季节GPS掩星廓线精度的比较研究[J]. 武汉大学学报(信息科学版), 2010, 35(6):639-643) [15] . Wang Yaoxing, Zhang Qiuzhao, Shen Zhen. Temporal and Spatial Analysis of COSMIC Occultation Inversion of Wet Temperature Profile Quality[J]. Geomatics and Information Science of Wuhan University, 2021, 46(6):887-894(王耀兴, 张秋昭, 沈震. COSMIC掩星反演湿温廓线质量的时空分析[J]. 武汉大学学报(信息科学版), 2021, 46(6):887-894) [16] . Chen Weiwei, Xiong Yongliang, Xu Shaoguang, et al. Analysis of Reflected Signals during GPS Radio Occultation Observations of COSMIC Products in China[J]. Geomatics and Information Science of Wuhan University, 2022, 47(2):189-196(陈伟伟, 熊永良, 徐韶光, 等. 中国区域COSMIC数据掩星反射信号特征分析[J]. 武汉大学学报(信息科学版), 2022, 47(2):189-196) [17] . Long H, Chen Q, Gong X, et al. Evaluation of the Planetary Boundary Layer Height in China Predicted by the CMA-GFS Global Model[J]. Atmosphere. 2022, 13(5):845.
[18] . Xu X, Zou X. COSMIC-2 RO Profile Ending at PBL Top with Strong Vertical Gradient of Refractivity[J]. Remote Sensing, 2022. 14(9):2189.
[19] . Healy S. ECMWF starts assimilating COSMIC-2 data[N]. ECMWF newsletter, No. 163, Spring 2020, 5-6.
[20] . Weiss J, Hunt D, Schreiner W, et al. COSMIC-2 Precise Orbit Determination Results[C]. EGU General Assembly 2020, Online, 4-8 May 2020, EGU2020-20170, 2020.
[21] . Fong C, Chu C, Lin C, et al. Toward the Most Accurate Thermometer in Space:FORMOSAT-7/COSMIC-2 Constellation[J]. IEEE Aerospace and Electronic Systems Magazine, 2019, 34(8):12-20.
[22] . Kursinski R, Hajj G, Schofield J, et al., Observing Earth's atmosphere with radio occultation measurements using the Global Positioning System[J]. Journal of Geophysical Research:Atmospheres, 1997. 102(D19):23429-23465.
[23] . Wickert J, Galas R, Beyerle G, et al. GPS ground station data for CHAMP radio occultation measurements[J]. Physics and Chemistry of the Earth, Part A:Solid Earth and Geodesy, 2001. 26(6):503-511.
[24] . Beyerle G, Schmidt T, Michalak G, et al. GPS radio occultation with GRACE:Atmospheric profiling utilizing the zero difference technique[J]. Geophysical Research Letters, 2005, 32(13), L13806.
[25] . Xia P, Ye S, Jiang K, et al. Estimation and evaluation of COSMIC radio occultation excess phase using undifferenced measurements[J]. Atmospheric Measurement Techniques, 2017, 10(5):1813-1821.
[26] . Schreiner W, Rocken C, Sokolovskiy S, et al. Quality assessment of COSMIC/FORMOSAT-3 GPS radio occultation data derived from single-and double-difference atmospheric excess phase processing[J]. GPS Solutions, 2010, 14(1):13-22.
[27] . Li Mingzhe, Zhang Shaocheng, Hu Youjian, et al. Comparison of GNSS Satellite Clock Stability Based on High Frequency Observations[J]. Geomatics and Information Science of Wuhan University, 2018, 43(10):1490-1495+1503(李明哲, 张绍成, 胡友健, 等.基于高频观测值的不同GNSS卫星钟稳定性分析[J]. 武汉大学学报(信息科学版), 2018, 43(10):1490-1495+1503) [28] . Schwarz J, Kirchengast G, Schwaerz M. Integrating uncertainty propagation in GNSS radio occultation retrieval:from excess phase to atmospheric bending angle profiles[J]. Atmospheric Measurement Techniques, 2018. 11(5):2601-2631.
[29] . Estey L, Meertens C. TEQC:The multi-purpose toolkit for GPS/GLONASS data[J]. GPS Solutions, 1999, 3(1):42-49.
[30] . Sokolovskiy S. Tracking tropospheric radio occultation signals from low Earth orbit[J]. Radio Science, 2001, 36(3):483-498.
[31] . Goff, J. A. Saturation pressure of water on the new Kelvin temperature scale[C]. The semi-annual meeting of the American society of heating and ventilating engineers, Murray Bay, Que. Canada, 1957.
计量
- 文章访问数: 424
- HTML全文浏览量: 43
- PDF下载量: 59