Transionospheric simulator for polar, auroral and equatorial ionospheres and its use in scintillation prediction and mitigation for GNSS systems.

极地、极光和赤道电离层的跨电离层模拟器及其在 GNSS 系统闪烁预测和缓解中的应用。

基本信息

批准号：
EP/D056187/1
负责人：
Hal John Strangeways
金额：
$ 17.18万
依托单位：
University of Leeds
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2006
资助国家：
英国
起止时间：
2006 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FD056187%2F1
关键词：
Transionospheric simulator polar auroral equatorial

项目摘要

Global satellite systems, such as GPS, are currently used in many applications to determine accurately the position ( and sometimes also velocity) of the GPS receiver. These signals travel from a GPS satellite at an altitude of about 20,000 km and travel through the ionosphere before arriving at a GPS receiver, typically near the surface of the Earth. The GPS receiver maintains a phase lock on the signal transmitted from the satellite in order to accurately determine the time it has taken the signal to travel from the satellite to the receiver and thus the distance between them. This enables the receiver to find its position from the determined distance to 4 or more GPS satellites. Just as we see stars twinkle due to the effect of the atmosphere so radio signals passing through the ionosphere scintillate . This means that they can show amplitude fades and phase perturbations. When the amplitude becomes very small or when the phase of the signal changes very rapidly and particularly when both occur together, loss of lock of the signal can result which means that the distance of the receiver from the satellite cannot be found. This is particularly the case for 3 specific latitude regions of the Earth: polar, auroral and equatorial. The polar ionosphere has fast moving patches of ionisation, the auroral ionosphere has field aligned sheets extended in longitude ( like an onion skin) and field-aligned cigar-shaped irregularities and the equatorial ionosphere has bubbles of considerably reduced electron density which form and travel upwards after sunset. In this project we will investigate this effect by constructing a model of the propagation path through the background ionosphere with these imbedded irregularities so that we can evaluate their effect for the different regions on the received signal at the GPS receiver for various different conditions, in particular when there is strong scintillation. We will also consider the effect of the scintillation of the received signal on the receiver phase locking and see what conditions have the most severe effect. We will also assess the effect of these scintillations on future satellite positioning systems which will transmit extra frequencies.

目前，在许多应用程序中使用了全局卫星系统，例如GPS，以准确确定GPS接收器的位置（有时也是速度）。这些信号从约20,000公里的高度从GPS卫星传播，然后穿过电离层，然后到达GPS接收器，通常在地球表面附近。 GPS接收器在从卫星传输的信号上保持一个相位锁定，以便确定信号从卫星传播到接收器的时间，从而将信号传播到接收器之间。这使得接收器能够从确定的距离到4个或更多GPS卫星找到其位置。正如我们看到大气效应所致的恒星闪烁一样，通过电离层闪烁的无线电信号。这意味着它们可以显示振幅褪色和相位扰动。当振幅变得很小，或者信号的相变很快而尤其是两者一起发生时，信号的锁定损失可能会导致，这意味着找不到接收器与卫星的距离。对于地球的3个特定纬度区域而言，尤其是这种情况：极性，极光和赤道。极性电离层具有快速移动的电离斑块，极光电离层具有经度的场对齐（例如洋葱皮）和野外对准的雪茄形的不规则性，并且赤道电离层具有大量降低的电子密度的气泡，并在日落后向上流动。在该项目中，我们将通过这些嵌入的不规则性通过背景电离层构建传播路径的模型来研究这种效果，以便我们可以在各种不同条件下评估它们对GPS接收器接收信号的影响，尤其是在强烈的闪烁时。我们还将考虑接收信号对接收器相位锁定的影响，并查看哪些条件最严重。我们还将评估这些闪烁对未来卫星定位系统的影响，这将传输额外的频率。