Project Loon based augmentation for global ionospheric modeling over Southern Hemisphere

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.

Drone assisted device to device cooperative communication for critical environments

“…It may be observed from Figure 5 that average magnitude of AF-noise is different for all four models. The average magnitude of AF-noise for Rayleigh (l 1 =l 2 =Ray) and Rician (l 1 =l 2 =Rice) models 2 are calculated using (10) and for the proposed probabilistic channel model by using (12). For the hybrid model, ℏ SR and ℏ RD are assumed Rayleigh distributed below an optimum drone height (h D 0 ≈18-22m as shown in Figure 4(a)) and Rician distributed above h D 0 .…”

“…Effective values of  l 1 ,l 2 and 𝜎 2  l 1 ,l 2 in case of statistical channel model can be found by averaging (10) and (11) over all the four possible cases (as discussed in Section 3) of various combinations of l 1 , l 2 as:…”

“…By adjusting the position of drone, the probability of LoS can be increased. Facebook [9] and Google [10] have been deploying a large number of drones for providing better services to rural areas. Amazon [11] is making use of small drones for service delivery purposes.…”

An Ionospheric Climate Index Based on GNSS

“…The ionospheric total electron content (TEC) is one of the significant parameters for physical studies of the ionosphere and practical applications mentioned above. The Global Navigation Satellite System (GNSS) with dual-frequency observations has been an effective way to monitor the ionospheric TEC for several decades (Feltens & Schaer, 1998;Hernández-Pajares et al, 2014;Mandrake et al, 2005;Wang et al, 2016Wang et al, , 2017. The International GNSS Service (IGS) has been providing observations of hundreds of GNSS stations since 1998 (Hernández-Pajares et al, 2009;Roma-Dollase et al, 2018;Wang et al, 2019), which are beneficial for ionospheric TEC modeling on the global scale.…”