Collaborative Research: NSWP--Scintillation-Scale Ionospheric Imaging using GPS and other RF Data in Inverse Diffraction Algorithms

合作研究：NSWP——在逆衍射算法中使用 GPS 和其他 RF 数据进行闪烁尺度电离层成像

• 批准号: 0719872
• 负责人: Gary Bust
• 金额: $ 12.24万
• 依托单位: ATMOSPHERIC & SPACE TECHNOLOGY RESEARCH ASSOCIATES, L.L.C.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0719872&HistoricalAwards=false
• 关键词: Collaborative; Research; NSWP; Scintillation; Scale

This project will infer fine-scale electron density variations of the equatorial ionosphere by developing and applying estimation algorithms to data recorded from scintillating GPS radio signals. The resulting electron density profiles will provide images of the bubble structures that are thought to cause the phenomena of radio frequency scintillations and equatorial spread-F. The project will include algorithm development, data collection campaigns, and data analysis. The algorithms to be developed will perform diffraction tomography calculations; the input data are received Radio Frequency (RF) signal amplitudes and phases from an array of receivers that are experiencing scintillations. The algorithms will estimate electron density profiles by developing and applying model estimation/inversion techniques to models such as a phase screen with Fresnel forward scattering. The estimation techniques will exploit the availability of dual-frequency GPS scintillation data that can be monitored because of new civilian GPS L2 signals now becoming available. They will also exploit the ability of GPS to make group-delay measurements; use of these data will follow development of a model predicting how group delay is affected by a disturbed ionosphere. The algorithms will be applied to data from two types of equatorial scintillation collection campaigns. One type of campaign will collect data using small arrays of wide-band digital storage receivers and MATLAB post-processing to acquire and track scintillating signals. The second type will use a medium sized array of real-time GPS software radio receivers. Some of the effort will go toward completing development of the latter type of receiver. Two distinctive features of this project are its use of very robust receiver technology, which will enable collection of very accurate RF amplitude and phase data for very strong scintillations and its development of generalized estimation/inversion algorithms. These algorithms that go beyond the capabilities of currently existing or proposed algorithms in their use of multi-frequency data, in their problem formulations, and in their algorithmic implementation based on optimization or fixed-point methods. The project focuses on very strong scintillations since these are the most important from an operational standpoint since they have the biggest impact on communications and navigation signals. The project's broader impacts include the development of instruments that can be used in education as well as in research and the improved communication and navigation system reliability that will result from an improved understanding of scintillations.

该项目将通过开发和应用估计算法对从闪烁的GPS无线电信号中记录的数据来推断赤道电离层的高尺度电子密度变化。所得的电子密度轮廓将提供气泡结构的图像，这些图像被认为会导致射频闪烁现象和赤道扩散f的现象。 该项目将包括算法开发，数据收集活动和数据分析。 要开发的算法将执行衍射断层扫描计算；输入数据是从经历闪烁的一系列接收器中接收到的射频（RF）信号幅度和阶段。该算法将通过开发和应用模型估计/反转技术来估算电子密度曲线，例如具有菲涅耳向前散射的相屏幕。估计技术将利用双频GPS闪烁数据的可用性，因为新的平民GPS L2信号现已可用，可以监视这些数据。他们还将利用全科医生进行组延迟测量的能力；这些数据的使用将遵循一个模型的开发，以预测群体延迟如何受到干扰电离层的影响。该算法将应用于两种类型的赤道闪烁收集活动的数据。一种类型的广告系列将使用较小的宽波段数字存储接收器和MATLAB后处理来收集数据，以获取和跟踪闪烁信号。第二种类型将使用中型的实时GPS软件无线电接收器。一些努力将用于完成后一种接收器的开发。该项目的两个独特功能是使用非常强大的接收器技术，这将使非常准确的RF振幅和相位数据收集，以实现非常强大的闪烁及其开发广义估计/反转算法。 这些算法超出了当前现有或提出的算法在使用多频数据，问题表述中以及基于优化或固定点方法的算法实现中的功能。 该项目的重点是非常强大的闪烁，因为从操作的角度来看，它们对通信和导航信号的影响最大，这是最重要的。 该项目的更广泛的影响包括可以在教育以及研究中使用的工具的开发以及改进的通信和导航系统可靠性，这将归因于对闪烁的了解得以提高。