The growing technological needs for multi-instrument datasets require proper understanding of the behaviour of the datasets relative to each other. This paper presents the first results of analysis on the relationship between in-situ ground refractivity measurements and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) refractivity measurements in the African equatorial region. In-situ measurements of surface refractivity obtained from four atmospheric ground stations in the region are compared with COSMIC-1 refractivity measurements at 1 km altitude. The in-situ datasets cover the periods from years 2007 to 2014, and corresponding COSMIC-1 datasets over the same period was used. Datasets from the recently launched COSMIC-2 mission (October 2019–September 2020) were utilized to show that the typical differences between refractivity values measured at 0 and 1 km altitudes are about 48 N-units. Interestingly, time-coincident measurements from COSMIC-1 (at 1 km altitude) and from ground in-situ measurements indicate that there is a similar typical difference (about 52 N-units) between refractivity values at the two altitudes. The reason for using COSMIC-2 measurements is that the altitudes covered by COSMIC-1 measurements start from a minimum of 0.1 km, and even at this altitude, the COSMIC-1 measurements are very scanty that there are no coincident observations with the in-situ ground stations. This is why it became imperative to first use COSMIC-2 measurements which cover altitudes from as low as 0 km. The reason is to validate that the difference between COSMIC measurements at 0 and 1 km altitudes are equivalent/comparable to difference between in-situ ground measurements and COSMIC measurements at 1 km. These results indicate that the COSMIC measurements at 0 km are comparable to the in-situ ground measurements.

对多仪器数据集不断增长的技术需求需要正确理解数据集相互之间的行为。本文介绍了非洲赤道地区原位地面折射率测量与气象、电离层和气候星座观测系统 (COSMIC) 折射率测量之间关系的初步分析结果。从该地区四个大气地面站获得的地面折射率的原位测量值与 1 公里高度的 COSMIC-1 折射率测量值进行了比较。原位数据集涵盖2007年至2014年期间，并使用了同期的相应COSMIC-1数据集。最近发射的 COSMIC-2 任务（2019 年 10 月至 2020 年 9 月）的数据集被用来表明在 0 和 1 公里高度测量的折射率值之间的典型差异约为 48 N 单位。有趣的是，来自 COSMIC-1（1 公里高度）和地面原位测量的时间重合测量表明，两个高度的折射率值之间存在类似的典型差异（约 52 N 单位）。使用 COSMIC-2 测量的原因是 COSMIC-1 测量所覆盖的高度从最低 0.1 公里开始，即使在这个高度，COSMIC-1 测量也非常稀少，没有与输入一致的观测值。现场地面站。这就是为什么必须首先使用覆盖低至 0 公里高度的 COSMIC-2 测量。原因是为了验证 0 和 1 公里高度的 COSMIC 测量值之间的差异与原位地面测量值和 1 公里处的 COSMIC 测量值之间的差异等效/可比。这些结果表明 0 km 处的 COSMIC 测量值与原位地面测量值具有可比性。