TOPEX/Poseidon, Jason-1, Jason-2 and Jason-3 altimeter missions have provided 27 + years of uninterrupted Total Electron Content (TEC) measurements since 1992, with unprecedented precision. Nevertheless, the issue of a possible systematic bias in the data was identified immediately after first TOPEX measurements were compared with measurements from other sources. The bias issue has remained open for decades, and it has increased in complexity because each new mission had its different bias. The purpose of this paper is to assess the problem of TEC bias of altimeters. Two approaches have been followed. The first one relied on the TEC data series of the four altimeters to determine inter-mission systematic biases using the last available data versions for each mission. The second approach consisted of inspecting the missions’ official reports to trace changes of the inter-mission and inter-version biases, including biases relative to DORIS ionospheric measurements. Both approaches have converged and resulted in the determination of a reference frame where missions, instruments and ionospheric reference levels could be compared. This reference frame was also used to analyze results published in representative papers during the last decades, including ionospheric data from the ENVISAT mission. This reference frame could help to assess TEC levels of the announced new data version of Jason-2, Jason-3 and the imminent Jason-CS/Sentinel missions. The main conclusion of this work is that Jason-1, ‘E’ data version, defines a TEC reference level which is compatible with most of the results found in the literature.

Highlights

• This contribution provides evidence in favor of TEC data series from Jason-1, ‘E’ version, as the most accurate reference level among altimeter missions and versions.

• This work tries to assess a long-lasting issue about the existence of systematic biases among ionospheric data series obtained from different satellite altimeters.

• This work establishes a TEC reference frame where it is possible to ‘map’ already published results and interpret their meanings.

• This work provides a frame where any possible bias in the upcoming ‘F’ data version series of Jason-2 and Jason-3, and of the imminent Jason-CS/Sentinel-6A mission could be detected.

自 1992 年以来，TOPEX/Poseidon、Jason-1、Jason-2 和 Jason-3 高度计任务以前所未有的精度提供了 27 多年不间断的总电子含量 (TEC) 测量。尽管如此，在将第一次 TOPEX 测量值与其他来源的测量值进行比较后，立即发现了数据中可能存在的系统偏差问题。偏见问题几十年来一直悬而未决，而且由于每个新任务都有不同的偏见，因此变得更加复杂。本文的目的是评估高度计的 TEC 偏差问题。遵循了两种方法。第一个依赖于四个高度计的 TEC 数据系列，使用每个任务的最后可用数据版本来确定任务间系统偏差。第二种方法包括检查任务的官方报告以追踪任务间和版本间偏差的变化，包括与 DORIS 电离层测量相关的偏差。这两种方法已经融合，并最终确定了一个参考系，在该参考系中可以比较任务、仪器和电离层参考水平。该参考框架还用于分析过去几十年发表在代表性论文中的结果，包括来自 ENVISAT 任务的电离层数据。该参考框架可以帮助评估已宣布的 Jason-2、Jason-3 和即将执行的 Jason-CS/Sentinel 任务的新数据版本的 TEC 水平。这项工作的主要结论是 Jason-1，'E' 数据版本，定义了一个与文献中发现的大多数结果兼容的 TEC 参考水平。

强调

• 这一贡献提供了支持来自 Jason-1，“E”版本的 TEC 数据系列的证据，作为高度计任务和版本中最准确的参考水平。

• 这项工作试图评估一个长期存在的问题，即从不同卫星高度计获得的电离层数据系列之间是否存在系统偏差。

• 这项工作建立了一个 TEC 参考框架，可以在其中“映射”已发表的结果并解释它们的含义。

• 这项工作提供了一个框架，可以检测到即将到来的 Jason-2 和 Jason-3 以及即将到来的 Jason-CS/Sentinel-6A 任务的“F”数据版本系列中的任何可能的偏差。