Development and application of GNSS remote sensing techniques for Earth Observation

GNSS对地观测遥感技术的发展与应用

• 批准号: 387726247
• 负责人: Professor Dr.-Ing. Harald Schuh
• 金额: --
• 依托单位: Institut für Geodäsie und Geoinformationstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2017
• 资助国家: 德国
• 起止时间: 2016-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/387726247?language=en
• 关键词: Development; application; GNSS; remote; sensing

The radio occultation (RO) technique uses a space-based Low Earth Orbit (LEO) satellite receiver to receive GPS/GNSS signals and perform limb sounding on the Earth atmosphere and ionosphere. Due to the success of FormoSat-3/ Constellation Observing System for Meteorology, Ionosphere and Climate (FS3/COSMIC) consisting of six micro-LEO satellites, the joint U.S. and Taiwan RO team, lead separately by the National Oceanic and Atmospheric Administration (NOAA) and Taiwan National Space Organization (NSPO), have decided to move forward with a COSMIC follow-on mission (called FS7/COSMIC2. The GNSS RO payload, named Tri-G GNSS Radio-occultation System (TGRS) will receive multi-channel GPS, GLONASS, and Galileo satellite signals and will be capable of tracking more than 10,000 RO observations per day after both low- and high-inclination constellations are fully deployed. It is expected that denser RO scintillation observations will be used to accurately structure and model the Earth atmosphere and ionosphere.In addition, the special kind of GNSS multi-path delay reflected from the Earth surface could be used to sense the Earth surface environments such as ocean altimetry and sea state. This has brought out the need of designing and developing appropriate receivers in order to track and process reflected and scattered GPS/GNSS signals in real-time to avoid the storage of huge volumes of raw data. We also propose to apply the Field Programmable Gate Array (FPGA) to the GPS/GNSS Reflectometer Instrument achieving a high synchronism and a most benefit of the available hardware resources. Using Simulink/Matlab, the FPGA can also compute complex Delay-Doppler Map (DDM) data in real-time by correlating the in-phase and quadrature components of the baseband signals. A real-time high resolution DDM reflectometer can be implemented at both GPS L1 and L2 frequency. This study will address new objectives and results of GNSS remote sensing in the atmosphere, ionosphere, ocean altimetry and sea state as well as new opportunities for the future FS7/COSMIC2 mission. The project will be accomplished at Institute of Geodesy and Geoinformation Science of Technische Universität Berlin (IGG TUBerlin) in close connection with scientists at Deutsches GeoForschungs Zentrum (GFZ) Potsdam and Taiwan GPS Science and Application Research Center (GPSARC) at National Central University (NCU).Objectives of the project can be summarized as:(1) using GPS/GNSS RO atmosphere data and developing advanced algorithms for the lower troposphere and climatological investigations,(2) retrieving and monitoring sporadic E (Es) layer, scintillations and related effects including vertical couplings, and(3) developing real-time FPGA based GPS/GNSS reflectometer for applications on ocean altimetry and sea state observations.

无线电掩星（RO）技术利用天基近地轨道（LEO）卫星接收器接收GPS/GNSS信号，并对地球大气层和电离层进行探测。​名为Tri-G GNSS无线电掩星系统（TGRS）的GNSS反卫星载荷将接收多通道GPS、GLONASS和伽利略卫星信号，并将能够在低倾角和高倾角星座完全部署后每天跟踪超过10,000次反卫星观测。预计更密集的RO闪烁观测将用于精确地构造和模拟地球大气和电离层。此外，从地球表面反射的特殊GNSS多径延迟可用于感知海洋高度和海况等地球表面环境。这就需要设计和开发合适的接收机，以便实时跟踪和处理反射和散射的GPS/GNSS信号，以避免存储大量的原始数据。我们还建议将现场可编程门阵列（FPGA）应用于GPS/GNSS反射计仪器，以实现高同步性和最大限度地利用可用硬件资源。利用Simulink/Matlab， FPGA还可以通过关联基带信号的同相分量和正交分量来实时计算复杂的延迟多普勒图（DDM）数据。一个实时的高分辨率DDM反射计可以在GPS L1和L2频率下实现。该研究将解决GNSS遥感在大气、电离层、海洋高度和海况方面的新目标和成果，以及未来FS7/COSMIC2任务的新机遇。该项目将在柏林工业大学大地测量学与地球信息科学研究所（IGG TUBerlin）完成，并与德国波茨坦地质研究中心（GFZ）和国立中央大学台湾GPS科学与应用研究中心（GPSARC）的科学家密切合作。该项目的目标可以总结为：(1)利用GPS/GNSS RO大气数据并开发对流层低层和气候调查的先进算法；(2)检索和监测散发E （Es）层，闪烁及其相关影响，包括垂直耦合；(3)开发基于FPGA的实时GPS/GNSS反射计，用于海洋测高和海况观测。