Abstract Daily harmonics of the ionosphere’s total electron content (TEC) can be mapped using Global Navigation Satellite Systems (GNSS), as recently accomplished by Lean and colleagues. Here those harmonics are determined (over oceans only) by tidal analysis of ionospheric path delay from dual-frequency radar altimetry. Data from TOPEX, Jason-1, and Jason-2 altimeters are used, with focus on periods of medium to high solar activity. Diurnal-band signals are aliased by the altimeter sampling, but TOPEX-Jason orbits were designed to achieve acceptable tidal aliasing. Altimeter maps reveal where corresponding GNSS-based maps are in error, generally near the geomagnetic equator where high-wavenumber features are overly smoothed. When ocean tides are deduced from single-frequency altimetry, a task that relies on accurate GNSS-based ionospheric path corrections, any TEC errors leak directly into the tide solutions. TEC errors near and west of the Weddell Sea are likely problematic for the CryoSat-2 mission.

中文翻译：

---

卫星测高电离层总电子含量的日谐波

摘要 正如 Lean 及其同事最近完成的那样，可以使用全球导航卫星系统 (GNSS) 绘制电离层总电子含量 (TEC) 的每日谐波。在这里，这些谐波是通过双频雷达测高仪对电离层路径延迟的潮汐分析确定的（仅在海洋上）。使用来自 TOPEX、Jason-1 和 Jason-2 高度计的数据，重点关注中到高太阳活动时期。昼夜波段信号通过高度计采样产生混叠，但 TOPEX-Jason 轨道的设计是为了实现可接受的潮汐混叠。高度计地图显示相应的基于 GNSS 的地图出错的地方，通常在地磁赤道附近，那里的高波数特征过于平滑。当从单频测高推导出海潮时，一项依赖于准确的基于 GNSS 的电离层路径校正的任务，任何 TEC 误差都会直接泄漏到潮汐解决方案中。威德尔海附近和西部的 TEC 误差可能会给 CryoSat-2 任务带来问题。