Sea surface height inversion of GPS reflected signal based on TechDemoSat-1 satellite
-
摘要:
针对星载GPS反射信号(GPS-R)海面测高的误差问题,基于星载GPS-R实测数据进行星载海面测高模型和误差修正模型的研究,并验证其有效性。利用TechDemoSat-1(TDS-1)数据,使用时延多普勒图(DDM)海面高度反演技术,着重分析了星载GPS-R海面高度反演中的各类误差,并建立了相应的误差模型。对星载GPS-R海面高度反演模型进行优化,采用DTU15全球平均海面模型、DTU全球海潮模型验证反演精度。结果证明:优化后反演模型得到的全球海面高度反演结果的平均绝对误差(MAD)为6.05 m,精度提高了约29%,有效提高了海面高度反演的精度。研究成果对于推广星载GNSS反射信号(GNSS-R)的海面测高应用具有一定的意义。
-
关键词:
- GNSS反射信号(GNSS-R) /
- 星载 /
- 海面高度反演 /
- 精度分析 /
- TechDemoSat-1(TDS-1)
Abstract:The problems of using GPS-Reflectometry (GPS-R) measured data to establish satellite-borne sea surface height inversion model are studied and its validity is verified. The data of TechDemoSat-1 (TDS-1) and the retrieval technique of Delay-Doppler Map (DDM) were used to analyze the errors in the retrieval of satellite-borne GPS-R sea surface height, and the error models were established. The satellite-borne GPS-R sea surface height inversion model was optimized. Meanwhile, the DTU15 global mean sea surface and sea tide model was adopted to verify the inversion accuracy. The results show that the Mean Absolute Deviation (MAD) of the global sea surface height inversion results obtained by the optimized inversion model is 6.05 meters, and the accuracy is improved by about 29%, effectively improving the accuracy of SST inversion. The research results have certain significance for promoting the application of spaceborne GNSS-Reflectometry (GNSS-R) in sea surface height inversion.
-
表 1 TDS-1卫星参数
Table 1. Parameters of satellite TDS-1
参数 数值 天线极化 天顶天线(L1/L2)、天底天线 采样率/MHz 16.367 轨道高度/km 635 轨道倾角/(°) 98.4 表 2 误差因素及补正方法
Table 2. Error factors and correction methods
误差项 延迟误差绝对值/m 补正方法 电离层 < 15 国际参考电离层模型 对流层 < 7 大气延迟模型 天基线姿态误差 < 1 TDS-1 Metadata数据 GPS卫星轨道误差 < 3 SP3精密星历 TDS-1卫星轨道误差 < 2 TDS-1 Metadata数据 反射信号延迟误差 < 10 反射信号几何模型 TDS-1卫星数据偏差 < 50 TDS-1 Metadata数据 海面粗糙度 < 10 HALF方法 表 3 筛选参数及范围
Table 3. Filter parameters and scope
参数 保留数据范围 信噪比/dB >-5 天线增益/dB >5 仰角/(°) >60 -
[1] 孙剑. GNSS-R海洋反射接收机的控制设计及实现[D]. 北京: 中国科学院空间科学与应用研究中心, 2010: 2-5.SUN J. Design and realization of control system for the GNSS-R receiver[D]. Beijing: Center for Space Science and Applied Research, Chinese Academy of Sciences, 2010: 2-5(in Chinese). [2] MARTIN-NEIRA M. A pasive reflectometry and interfeometry system (PARIS) application to ocean altimetry[J]. ESA Journal, 1993, 17(4): 331-355. [3] PARK H, VALENCIA E, CAMPS A, et al. Delay tracking in spaceborne GNSS-R ocean altimetry[J]. IEEE Geoscience and Remote Sensing Letters, 2013, 10(1): 57-61. doi: 10.1109/LGRS.2012.2192255 [4] 张云, 谢向芳, 孟婉婷, 等. 基于北斗GEO卫星反射信号的渤海海冰检测[J]. 北京航空航天大学学报, 2018, 44(2): 257-263. doi: 10.13700/j.bh.1001-5965.2017.0149ZHANG Y, XIE X F, MENG W T, et al. Bohai coastal sea ice detection using BeiDou GEO satellite reflected signals[J]. Journal of Beijing University of Aeronautics and Astronautics, 2018, 44(2): 257-263(in Chinese). doi: 10.13700/j.bh.1001-5965.2017.0149 [5] ZHANG Y, TIAN L M, MENG W T, et al. Feasibility of code-level altimetry using coastal BeiDou reflection (BeiDou-R) setups[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2015, 8(8): 4130-4140. doi: 10.1109/JSTARS.2015.2446684 [6] ZHANG Y, LI B B, TIAN L M, et al. Phase altimetry using reflected signals from BeiDou GEO satellites[J]. IEEE Geoscience and Remote Sensing Letters, 2016, 13(10): 1-5. doi: 10.1109/LGRS.2016.2596724 [7] 刘风玲, 张云, 孟婉婷, 等. UK-DMC卫星接收机GNSS反射信号的应用分析[J]. 遥感信息, 2015, 30(1): 90-95. https://www.cnki.com.cn/Article/CJFDTOTAL-YGXX201501015.htmLIU F L, ZHANG Y, MENG W T, et al. Application analysis of airborne GNSS reflected data from UK-DMC satellite receiver[J]. Remote Sensing Information, 2015, 30(1): 90-95(in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-YGXX201501015.htm [8] CLARIZIA M P, RUF C, CIPOLLINI P, et al. First spaceborne observation of sea surface height using GPS-reflectometry[J]. Geophysical Research Letters, 2016, 43(2): 767-774. doi: 10.1002/2015GL066624 [9] MASHBURN J, AXELRAD P, LOWE S T, et al. Global ocean altimetry with GNSS reflections from TechDemoSat-1[J]. IEEE Transactions on Geoscience and Remote Sensing, 2018, 56(7): 4088-4097. doi: 10.1109/TGRS.2018.2823316 [10] LI W Q, CARDELLACH E, FABRA F, et al. Assessment of spaceborne GNSS-R ocean altimetry performance using CYGNSS mission raw data[J]. IEEE Transactions on Geoscience and Remote Sensing, 2020, 58(1): 238-250. doi: 10.1109/TGRS.2019.2936108 [11] XU L W, WAN W, CHEN X W, et al. Spaceborne GNSS-R observation of global lake level: First results from the TechDemoSat-1 mission[J]. Remote Sensing, 2019, 11(12): 1438. doi: 10.3390/rs11121438 [12] 张云, 张杨阳, 孟婉婷, 等. 机载GNSS反射信号海面测高模型的研究[J]. 海洋学报, 2020, 42(3): 149-156. https://www.cnki.com.cn/Article/CJFDTOTAL-SEAC202003014.htmZHANG Y, ZHANG Y Y, MENG W T, et al. Research on sea surface altimetry model of airborne GNSS reflected signal[J]. Acta Oceanologica Sinica, 2020, 42(3): 149-156(in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-SEAC202003014.htm [13] JALES P. MERRByS product manual-GNSS reflectometry on TDS-1 with the SGRReSI V4[EB/OL]. (2018-01-02)[2020-07-01]. http://merrbys.co.uk/resources/documentation. [14] GARRISON J L, KATZBERG S J. The application of reflected GPS signals to ocean remote sensing[J]. Remote Sensing of Environment, 2000, 73(2): 175-187. doi: 10.1016/S0034-4257(00)00092-4 [15] BILITZA D. The international reference ionosphere-status 2013[J]. Advances in Space Research, 2015, 55(8): 1914-1927. doi: 10.1016/j.asr.2014.07.032 [16] NIELL A E. Global mapping functions for the atmosphere delay at radio wavelengths[J]. Journal of Geophysical Research Solid Earth, 1996, 101(B2): 3227-3246. doi: 10.1029/95JB03048 [17] DOW J M, NEILAN R E, RIZOS C. The international GNSS service in a changing landscape of global navigation satellite systems[J]. Journal of Geodesy, 2009, 83(3-4): 191-198. doi: 10.1007/s00190-008-0300-3 [18] HU C J, BENSON C R, RIZOS C, et al. Impact of receiver dynamics on space-based GNSS-R altimetry[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2019, 12(6): 1974-1980. doi: 10.1109/JSTARS.2019.2910544 [19] ANDERSEN O B. The DTU10 gravity field and mean sea surface[C]//Second International Symposium of the Gravity Field of the Earth (IGFS2), 2010. [20] MASHBURN J, AXELRAD P, LOWE S T, et al. An assessment of the precision and accuracy of altimetry retrievals for a Monterey Bay GNSS-R experiment[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2016, 9(10): 4660-4668. doi: 10.1109/JSTARS.2016.2537698