Multi-instrument and multi-station observations and predictions of low- and mid-latitude ionospheric irregularities

增强的东向电场（称为反转前增强（PRE））或大气重力波可以引起显著的电离层不规则性，例如赤道等离子体泡（EPB）。这种电离层的不规则性会引起无线电振荡，从而在接收跨电离层无线电波时引起信号丢失和/或相位周跳。在这一设想中，建议组织和（或）开发多指令和多站系统，用于电离层闪烁和赤道扩展-F（ESF）规范以及低纬度和中纬度区域不规则现象发生的预测。首先，我们使用FS 7/COSMIC 2 GPS/GLONASS无线电掩星（RO）观测表明存在等离子体泡。我们使用位于东亚地区的垂直入射脉冲电离层雷达（VIPIR）网络记录的电离图来验证跟踪的等离子体泡的纬度范围。我们进一步讨论了空间和时间的变化的二维垂直闪烁指数VS 4地图的基础上，同时从位于台湾的130多个地面接收器的GPS L1波段信号测量。我们还在台湾运营了四个以上的高采样软件定义GPS和SBAS接收器，在埃塞俄比亚运营了一个小型高速GNSS网络，并通过对接收信号进行频谱分析来表征目标等离子体不规则性。此外，我们认为，日落后递减的固定频率电离层回波的虚拟高度可能是一个很好的前兆日落后闪烁和ESF事件。这些特征可用于与国际参考电离层（IRI）检索的等离子体漂移和从TIMED/SABER卫星测量检索的重力波活动的相关性分析，因此，预计将伴随着一个预测模型。这项研究将探讨FS 7/COSMIC 2进行的更密集的全球导航卫星系统RO观测以及全球定位系统/全球导航卫星系统接收器和电离层遥感雷达进行的联合地面观测的新目标和结果，以准确构建地球低纬度和中纬度电离层不规则性并建立模型。所有拟议目标概述如下：（1） 使用FS 7/COSMIC 2 GNSS RO观测和VIPIR网络识别EPB，（2） 分别使用FS 7/COSMIC 2和地基GNSS网络确定全球大尺度和区域中小尺度EPB分布，（3） 使用高采样GNSS接收器确定电离层不规则强度、规模和运动的特征，以及（4） 基于等离子体漂移和重力波活动参数的相关性分析，对土压平衡的发生进行建模和预测。

Significant ionospheric irregularities, e.g. equatorial plasma bubbles (EPB), could be induced by enhanced eastward electric field, called pre-reversal enhancement (PRE), or atmospheric gravity wave. Such ionospheric irregularities could induce radio scintillations which cause signal loss and/or phase cycle slips in receiving trans-ionospheric radio wave. In this scenario, multi-instruction and multi-station systems are proposed to be organized and/or developed for ionospheric scintillation and equatorial spread-F (ESF) specification and prediction of irregularity occurrence in the low- and mid-latitude regions. We first indicate the existence of a plasma bubble using the FS7/COSMIC2 GPS/GLONASS radio occultation (RO) observations. We verify the latitudinal extent of the tracked plasma bubble using the recorded ionograms from the Vertical Incidence Pulsed Ionospheric Radar (VIPIR) network located in the east-Asia area. We further discuss the spatial and temporal variabilities of two-dimensional vertical scintillation index VS4 maps based on the simultaneous GPS L1-band signal measurements from more than 130 ground-based receivers located in Taiwan. We also operate more than four high-sampling software-defined GPS&SBAS receivers in Taiwan and a small-scale high-rate GNSS network in Ethiopia and characterize the targeted plasma irregularities by carrying out spectrum analyses of the received signal. Furthermore, we suggest that a post sunset decrement on the virtual heights of fixed-frequency ionospheric echoes could be a good precursor for post sunset scintillation and ESF events. Such features can be used for correlation analysis with plasma drifts retrieved by the International Reference Ionosphere (IRI) and gravity wave activity retrieved from TIMED/SABER satellite measurements, and, as a result, a prediction model is expected to be accompanied. This study will address new objectives and results of denser GNSS RO observations from the FS7/COSMIC2 and joint ground-based observations from GPS/GNSS receivers and ionospheric remote sensing radar to accurately structure and model the Earth’s low- and mid-latitude ionospheric irregularity. All proposed objectives are summarized below: (1) identify EPB using FS7/COSMIC2 GNSS RO observations and the VIPIR network, (2) determine global large-scale and regional meso- or small-scale EPB distributions using FS7/COSMIC2 and ground-based GNSS network, respectively, (3) characterize ionospheric irregularity intensity, scale and movement using high-sampling GNSS receivers, and (4) model and predict EPB occurrence based on correlation analysis with plasma drift and gravity wave activity parameters.