陈亮宇, 安家春, 王泽民, 柳景斌, 屈小川. 同天线不同接收机的GNSS-IR雪深反演分析[J]. 武汉大学学报 ( 信息科学版), 2023, 48(8): 1312-1321. DOI: 10.13203/j.whugis20210710
引用本文: 陈亮宇, 安家春, 王泽民, 柳景斌, 屈小川. 同天线不同接收机的GNSS-IR雪深反演分析[J]. 武汉大学学报 ( 信息科学版), 2023, 48(8): 1312-1321. DOI: 10.13203/j.whugis20210710
CHEN Liangyu, AN Jiachun, WANG Zemin, LIU Jingbin, QU Xiaochuan. Assessment of GNSS-IR-Based Snow-Depth Retrievals Using Observations from Different Receivers with the Same Antenna[J]. Geomatics and Information Science of Wuhan University, 2023, 48(8): 1312-1321. DOI: 10.13203/j.whugis20210710
Citation: CHEN Liangyu, AN Jiachun, WANG Zemin, LIU Jingbin, QU Xiaochuan. Assessment of GNSS-IR-Based Snow-Depth Retrievals Using Observations from Different Receivers with the Same Antenna[J]. Geomatics and Information Science of Wuhan University, 2023, 48(8): 1312-1321. DOI: 10.13203/j.whugis20210710

同天线不同接收机的GNSS-IR雪深反演分析

Assessment of GNSS-IR-Based Snow-Depth Retrievals Using Observations from Different Receivers with the Same Antenna

  • 摘要: 全球导航卫星系统(global navigation satellite system,GNSS)干涉遥感技术(GNSS-interferometry reflectometry, GNSS-IR)利用测量型GNSS接收机即可获取反射面信息,具有信号源丰富、采样率高等优势,被广泛应用于雪深、潮位、土壤湿度、海面风场、海冰探测、地表形变监测等领域的研究。然而,GNSS接收机会对接收信号进行多路径抑制,反射信号会被削弱甚至剔除,从而降低GNSS-IR技术的精度。为了探讨GNSS-IR反演中不同接收机、不同频点的影响,基于零基线模式在中国北极黄河站设计了GNSS-IR雪深反演实验,定量研究了接收机性能对雪深反演精度的影响。首先,在站上布设了和芯星通接收机和天宝接收机,并通过功分器共用同一个天线,这样可以获得反射面完全相同的多接收机、多频点观测值;然后,对两台接收机在3个GPS频点下的日均反演结果进行比较以便验证反演策略的有效性,并通过单次反演结果对比分析不同接收机反演效果的差异。结果表明,多个接收机、多个频点都能成功反演雪深值,其偏差基本上在3 cm以内。但是,尽管反射面完全相同,两个接收机之间、3个频点之间的雪深反演仍然存在一定差异,尤其在积雪变化迅速的时段这种差异更大,这也意味着在高精度的GNSS-IR反演中不能忽略接收机性能的影响。

     

    Abstract:
      Objectives  The emerging global navigation satellite system (GNSS) interferometric reflectometry (GNSS-IR) technique can obtain the information of reflector using geodetic GNSS receiver, and has been extensively applied to the research on snow depth, tide level, soil moisture, sea surface wind and so on. However, multipath suppression technique is often adopted in geodetic GNSS receiver and the reflected signal will be weakened or even eliminated, which will undoubtedly reduce the performance of GNSS-IR. Therefore, the influence of multi-receiver and multi-frequency on GNSS-IR should be carefully investigated.
      Methods  By learning from the method of zero baseline, we design an experiment of snow depth retrievals using GNSS-IR at Chinese Arctiv Yellow River Station in Svalbard, and quantitatively illustrate the influence of receiver performance on the accuracy of snow depth retrievals. In the experiment, two different GNSS receivers are connected to the same antenna with a power divider. It brings a special benefit that the observations of two receivers at three frequencies are derived from absolutely the same reflector. After collecting enough data, the daily average retrievals of the two receivers in the three frequencies are compared in order to verify the effectiveness of the retrieval strategy. Then the differences in the retrieval of different receivers are compared and analyzed to check the influence of receivers.
      Results  The results show that the observations of each receiver and each frequency can be used to retrieve snow depth and the bias is in 3 cm. However, in spite of the same reflector, the differences between the snow depth retrievals from two receivers and three frequencies remain, especially when the snow depth changes rapidly.
      Conclusions  Different receivers have different methods to suppress multipath effect, which will affect the retrieval effect of GNSS-IR. Therefore, when using geodetic GNSS receivers for GNSS-IR retrievals, the difference brought by receivers cannot be ignored. If the method of multipath suppression can be properly considered in GNSS data processing, it should be helpful to improve the accuracy of GNSS-IR retrievals.

     

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