A new method is proposed for the combination of global ionospheric maps provided by the seven IGS centers. Through comparison, the GIMs of the seven centers presents different performance during the past 19 years. The assessment shows that the new combined GIMs are more reliable than the IGS official ionospheric products.

中文翻译：

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由七个IGS分析中心的电离层产品组合而成的更可靠的全球电离层图

提出了一种新的方法来组合由七个IGS中心提供的全球电离层图。通过比较，七个中心的GIM在过去19年中表现不同。评估表明，新的组合GIM比IGS官方电离层产品更可靠。