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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.


Bias and RMS values of the differences between WHU products and IGS GIMs as well as IAACs’ products during DOY 152–181, 2015.
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f7: Bias and RMS values of the differences between WHU products and IGS GIMs as well as IAACs’ products during DOY 152–181, 2015.

Mentions: Since the balloons are supposed to be deployed at the 25th and 50th parallel south, it is necessary to investigate the performance of the augmentation over southern latitudes. According to the geographical distribution of IPPs by the augmentation in Fig. 1, the VTEC values covering from 20°S to 60°S are collected for the investigation. Figure 7 shows that the bias and RMS values of the differences over the globe and southern latitudes (20°S–60°S) between WHU products and IGS GIMs as well as IAACs’ products during DOY 152–181, 2015, respectively. Also, the differences over the specified southern latitudes among the IAACs’ products are presented in Table 3. Firstly, according to RMS values, the magnitude of differences over globe is apparently larger than that over the specified southern latitudes. Because there are more differences of VTEC maps over other regions besides specified southern latitudes. Also, the bias and RMS values for global comparison have changed little by the augmented solution. However, for the specified southern latitudes, there are an obvious change after taking the augmentation of Project Loon. Additionally, RMS value of the differences between WHU_IRI and JPL GIMs are a little smaller. While, the RMS values between WHU_IRI and GIMs from CODE, ESA and UPC seem to become larger. It doesn’t indicate that the modeling with Project Loon based augmentation would have no improvement. The explanation could be referred to the previous paragraph.


Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere
Bias and RMS values of the differences between WHU products and IGS GIMs as well as IAACs’ products during DOY 152–181, 2015.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f7: Bias and RMS values of the differences between WHU products and IGS GIMs as well as IAACs’ products during DOY 152–181, 2015.
Mentions: Since the balloons are supposed to be deployed at the 25th and 50th parallel south, it is necessary to investigate the performance of the augmentation over southern latitudes. According to the geographical distribution of IPPs by the augmentation in Fig. 1, the VTEC values covering from 20°S to 60°S are collected for the investigation. Figure 7 shows that the bias and RMS values of the differences over the globe and southern latitudes (20°S–60°S) between WHU products and IGS GIMs as well as IAACs’ products during DOY 152–181, 2015, respectively. Also, the differences over the specified southern latitudes among the IAACs’ products are presented in Table 3. Firstly, according to RMS values, the magnitude of differences over globe is apparently larger than that over the specified southern latitudes. Because there are more differences of VTEC maps over other regions besides specified southern latitudes. Also, the bias and RMS values for global comparison have changed little by the augmented solution. However, for the specified southern latitudes, there are an obvious change after taking the augmentation of Project Loon. Additionally, RMS value of the differences between WHU_IRI and JPL GIMs are a little smaller. While, the RMS values between WHU_IRI and GIMs from CODE, ESA and UPC seem to become larger. It doesn’t indicate that the modeling with Project Loon based augmentation would have no improvement. The explanation could be referred to the previous paragraph.

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.