3-D Computerized Ionospheric Tomography With GPS, SAR, and Ionosonde

The Global Positioning System (GPS)-based computerized ionospheric tomography (CIT) has the capacity to reconstruct the 3-D ionosphere (i.e., electron density distribution), making it one of the most important techniques for ionospheric observation. However, the CIT technology is unable of high vertical resolution due to the restricted viewing angle. Therefore, the precision of CIT cannot be substantially enhanced with GPS only. Aiming at this issue, this article proposes a bi-iteration algorithm that integrates GPS, Phased Array L-band Synthetic Aperture Radar on board the Advanced Land Observing Satellite (ALOS PALSAR), and ionosonde data. The key is that the joint retrieval of PALSAR and ionosonde may offer a high-precision 1-D electron density profile along the whole path, which can effectively enhance the authenticity of the iterative initial value. The corrected initial value is then fused into the process of CIT, which can finally improve the precision of vertical resolution after two iterations. Experimental verification demonstrates that due to the ability to obtain more realistic initial values, the reconstruction accuracy of the algorithm proposed in this article is 51.4% and 45.1% higher than the accuracy with GPS alone and with GPS and ionosonde data, respectively. This indicates that the combination of these three kinds of data can effectively improve the precision of CIT.

Automated summary

This article proposes a bi-iteration algorithm that integrates GPS, PALSAR, and ionosonde data to improve the precision of ionospheric tomography. Experimental verification demonstrates that the reconstruction accuracy of the algorithm is significantly higher compared to using GPS alone or combining GPS and ionosonde data, indicating the effectiveness of combining these three kinds of data in improving the precision of CIT.