A new two-step algorithm for ionospheric tomography solution

作者：Wen, Debao^*; Wang, Yong; Norman, Robert

来源：GPS Solutions, 2012, 16(1): 89-94.

DOI：10.1007/s10291-011-0211-2

• Computerized ionospheric tomography
• Total electron content
• Ionospheric electron density
• Ill-conditioned
• Two-step algorithm
• MART

Ionospheric tomography inverse algorithms are usually an ill-conditioned problem because the geometric distribution of continuously operating reference GPS stations is not ideal for this task. In order to cope with such ill-conditioning, a new tomographic algorithm, termed two-step algorithm (TSA), is presented. The electron density is estimated in two steps: Phillips smoothing method (PSM) is first used to resolve the ill-conditioned problem in the ionospheric tomography system, and then, the PSM solution is input as an initial value to the multiplicative algebraic reconstruction technique (MART) and iteratively improved. Numerical simulations using the International Reference Ionosphere 2007 model demonstrate that the TSA is applicable to GPS-based ionospheric tomography reconstruction and is superior to PSM and MART when these techniques are used alone. The new algorithm is applied to reconstruct the ionospheric electron density distribution over China using GPS observations, and a comparison with ionosonde observations is made.

• 出版日期2012-1
• 单位河南理工大学; 长沙理工大学