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Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere

View Article: PubMed Central - PubMed

ABSTRACT

Global ionospheric products of vertical total electron content (VTEC) derived from GNSS measurements may have low accuracy over oceans and southern latitudes where there are not rich observations. Project Loon provides a great opportunity to enhance the measurements over those areas. In this contribution, a simulation of Project Loon based augmentation for global ionospheric modeling is performed by using the international reference ionosphere (IRI) which could simulate VTEC measurements for the balloons. The performance of the enhanced method based on simulation of Project Loon is investigated by comparing with VTEC maps from Ionosphere Associate Analysis Centers (IAACs) as well as IGS final GIMs. The comparison indicates that there is a better consistency between the VTEC maps by the enhanced method and IGS final GIMs. Also, obvious improvements of RMS maps in GIMs for the middle latitudes and southern latitudes are enabled by the augmentation of Project Loon. Additionally, JASON data are used to validate the specific improvement of the VTEC maps. The results show that the performance of VTEC maps is improved slightly, especially in southern latitudes. It is possible that the VTEC maps could be improved significantly by using real GPS measurements from balloons of Project Loon in the near future.

No MeSH data available.


Map showing the geographical distribution of IGS stations, 40 balloons and IPPs.The red and blue dots present the distribution of IGS stations and balloons, respectively. The grey and green lines depict the IPPs observed by ground-based stations and Project Loon balloons, respectively. This figure is drawn using Gnuplot V5.0 (http://gnuplot.sourceforge.net) with map data of the world from Natural Earth (http://www.naturalearthdata.com/downloads/).
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f1: Map showing the geographical distribution of IGS stations, 40 balloons and IPPs.The red and blue dots present the distribution of IGS stations and balloons, respectively. The grey and green lines depict the IPPs observed by ground-based stations and Project Loon balloons, respectively. This figure is drawn using Gnuplot V5.0 (http://gnuplot.sourceforge.net) with map data of the world from Natural Earth (http://www.naturalearthdata.com/downloads/).

Mentions: Google has done several pilot experiments in New Zealand, Brazil and South Africa, etc. since 201320. Some experiments have made successful, while some balloons crashed. Since Project Loon is still in the experimental stage, the augmentation for global ionospheric modeling based on Loon balloons could be simulated by using existed empirical models such as IRI model or NeQuick. In this study, 40 balloons are supposed to be deployed at the 25th and 50th parallel south. There are 20 balloons at each parallel south. Figure 1 shows the global geographical distribution of approximately 325 IGS stations, balloons and the ionospheric pierce points (IPPs) during a 24-hour period. In the simulation of Project Loon based augmentation, the location of each balloon is supposed to be confirmed. So each balloon could be considered as a station like IGS stations. The only difference is that IGS stations are installed on the ground in contrast to the balloons being deployed in the stratosphere. These balloons could also observe the GPS satellites and get the ionospheric TEC. And in this study, the VTEC values at IPP observed by the balloons are simulated by IRI model.


Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere
Map showing the geographical distribution of IGS stations, 40 balloons and IPPs.The red and blue dots present the distribution of IGS stations and balloons, respectively. The grey and green lines depict the IPPs observed by ground-based stations and Project Loon balloons, respectively. This figure is drawn using Gnuplot V5.0 (http://gnuplot.sourceforge.net) with map data of the world from Natural Earth (http://www.naturalearthdata.com/downloads/).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5382668&req=5

f1: Map showing the geographical distribution of IGS stations, 40 balloons and IPPs.The red and blue dots present the distribution of IGS stations and balloons, respectively. The grey and green lines depict the IPPs observed by ground-based stations and Project Loon balloons, respectively. This figure is drawn using Gnuplot V5.0 (http://gnuplot.sourceforge.net) with map data of the world from Natural Earth (http://www.naturalearthdata.com/downloads/).
Mentions: Google has done several pilot experiments in New Zealand, Brazil and South Africa, etc. since 201320. Some experiments have made successful, while some balloons crashed. Since Project Loon is still in the experimental stage, the augmentation for global ionospheric modeling based on Loon balloons could be simulated by using existed empirical models such as IRI model or NeQuick. In this study, 40 balloons are supposed to be deployed at the 25th and 50th parallel south. There are 20 balloons at each parallel south. Figure 1 shows the global geographical distribution of approximately 325 IGS stations, balloons and the ionospheric pierce points (IPPs) during a 24-hour period. In the simulation of Project Loon based augmentation, the location of each balloon is supposed to be confirmed. So each balloon could be considered as a station like IGS stations. The only difference is that IGS stations are installed on the ground in contrast to the balloons being deployed in the stratosphere. These balloons could also observe the GPS satellites and get the ionospheric TEC. And in this study, the VTEC values at IPP observed by the balloons are simulated by IRI model.

View Article: PubMed Central - PubMed

ABSTRACT

Global ionospheric products of vertical total electron content (VTEC) derived from GNSS measurements may have low accuracy over oceans and southern latitudes where there are not rich observations. Project Loon provides a great opportunity to enhance the measurements over those areas. In this contribution, a simulation of Project Loon based augmentation for global ionospheric modeling is performed by using the international reference ionosphere (IRI) which could simulate VTEC measurements for the balloons. The performance of the enhanced method based on simulation of Project Loon is investigated by comparing with VTEC maps from Ionosphere Associate Analysis Centers (IAACs) as well as IGS final GIMs. The comparison indicates that there is a better consistency between the VTEC maps by the enhanced method and IGS final GIMs. Also, obvious improvements of RMS maps in GIMs for the middle latitudes and southern latitudes are enabled by the augmentation of Project Loon. Additionally, JASON data are used to validate the specific improvement of the VTEC maps. The results show that the performance of VTEC maps is improved slightly, especially in southern latitudes. It is possible that the VTEC maps could be improved significantly by using real GPS measurements from balloons of Project Loon in the near future.

No MeSH data available.