US-Nigeria Cooperative Research: Improvements of the International Reference Ionosphere at Low Latitudes

0002144 Bilitza该奖项支持马里兰州格林贝尔特戈达德航天飞行中心的Dieter Bilitza博士、尼日利亚Ilorin大学物理系的Jacob Olusegun Adeniyi教授和象牙海岸科科迪大学L大气实验室的Olivier Obrou教授之间为期三年的合作研究项目。电离层是大气层中位于中层和外层之间的那部分。它的各层被太阳紫外线辐射电离，这有助于某些无线电波在地球上长距离传输。对于任何使用电离层无线电波传输其信号的地面或空间遥感技术来说，对电离层电子密度的充分了解都是至关重要的。用于确定这些密度的最广泛使用的模型--国际参考电离层--缺乏对出现最大电子密度的低纬地区的描述，这限制了其提供导航和通信系统所需的校正的能力。这三名研究人员将分析位于布基纳法索、尼日利亚和象牙海岸磁赤道附近的四个地面探测仪收集的电离层底部电子密度剖面的赤道观测数据。这一结果将用于改进IRI模型中的电子密度规范。这一信息补充了美国、印度和太平洋地区现有的测量，并完成了磁赤道附近地面探测仪纵向链的电子密度数据的收集。这些数据集还将使研究人员能够对非洲地区赤道电离层的可变性进行量化描述。该项目将在四个台站进行的手动电离图定标与现代电离图缩减技术相结合。通过这一项目，主要研究人员期望更好地了解形成赤道电离层的过程，这将导致IRI标准模型的改进。包括非洲测量值在内的最新IRI模型将使未来的研究人员受益，它还将在高频和地面对卫星通信系统中得到广泛应用。此外，预期的结果应该会扩大关于电离层物理的知识。国际方案司和大气科学司将共同为该项目提供资金。

0002144BilitzaThis award supports a three-year collaborative research project among Dr. Dieter Bilitza, with the Raytheon Technical Services Company at Goddard Space Flight Center in Greenbelt, MD; Professor Jacob Olusegun Adeniyi, of the Department of Physics at the University of Ilorin in Nigeria; and Professor Olivier Obrou, at the Laboratoire de Physique de l'Atmosphere at the University of Cocody in the Ivory Coast. The ionosphere is that part of the atmosphere which lies between the mesophere and the exosphere. Its layers are ionized by solar ultraviolet radiation, which facilitates the transmission of certain radio waves over long distances on earth. A good knowledge of ionospheric electron density is essential for any ground or space remote sensing technique that uses the ionospheric radio waves for the transmission of its signals. The most widely used model for determining these densities, the International Reference Ionosphere (IRI), lacks a description of the low latitude regions where the largest electron densities occur, which limits its ability to provide the corrections needed by navigation and communications systems. The three investigators will analyze equatorial observations of the bottom-side ionospheric electron density profiles collected by four ground-based sounders located near the magnetic equator in Burkina Faso, Nigeria, and the Ivory Coast. The results will be used to improve the specification of electron density in the IRI model. This information complements existing measurements in the American, Indian, and Pacific sectors, and completes the collection of electron density data from the longitudinal chain of ground-based sounders near the magnetic equator. These data sets will also enable the researchers to develop a quantitative description of the variability of the equatorial ionosphere in the African sector. This project combines the manual ionogram scaling done at the four stations with modern ionogram reduction techniques. Through this project the principal investigators expect to achieve a better understanding of the processes that shape the equatorial ionosphere, which will lead to improvements in the IRI standard model. An updated IRI model, which includes African measurements, will benefit future researchers, and it will also have broad application in high frequency and ground-to-satellite communications systems. Additionally, the anticipated results should expand the knowledge about ionospheric physics.The Division of International Programs and the Division of Atmospheric Sciences are jointly providing funding for this project.