CNOFS CINDI IVM 500 ms Ion Drift Data

This data set contains plasma parameters of the equatorial F-region in the ionosphere measured by the Ion Velocity Meter (IVM) of the Coupled Ion-Neutral Dynamics Investigation (CINDI) payload on board the CNOFS spacecraft. Data are available in HDF format, with an IDL program to read and plot them. Each file contains data from one day of spacecraft operation and the file contains eight primary geophysical parameters: the ion temperature (Ti) in degrees Kelvin, the ion flow in m/s in the ram (i.e.--spacecraft velocity) direction (+Vx in the direction of spacecraft velocity), the ion flows in m/s in the horizontal and vertical directions (Vy and Vz) at right angles to the ram direction (+Vz is downward, +Vy is roughly southward), the total ion density (Ni) (the sum of O+ and H+ and He+ concentrations) in ions/cc, and the individual H+, He+, and O+ concentrations in ions/cc. In addition, ion velocities also are given in the coordinate system of the local magnetic field (parallel, perpendicular, and meridional) in the plots and as ASCII data on the UT Dallas website. Based on the IGRF model, the data are transformed into magnetic coordinates only if all three ion velocities in the spacecraft coordinates are available and good.

本数据集包含由CNOFS航天器搭载的耦合离子-中性动力学研究（CINDI）有效载荷中的离子速度计（IVM）测量的电离层赤道F区等离子体参数。数据以HDF格式提供，并附带用于读取和绘图的IDL程序。每个文件包含航天器一天运行的数据，且包含八个主要地球物理参数：开尔文度表示的离子温度（Ti）、冲压方向（即航天器速度方向，+Vx为航天器速度方向）上以米每秒为单位的离子流、与冲压方向垂直的水平和垂直方向（Vy和Vz，+Vz向下，+Vy大致向南）上以米每秒为单位的离子流、以离子每立方厘米为单位的总离子密度（Ni，即O+、H+和He+浓度之和），以及各离子（H+、He+、O+）以离子每立方厘米为单位的浓度。此外，离子速度还在绘图中以局域磁场坐标系（平行、垂直和子午向）给出，并在得克萨斯大学达拉斯分校网站上以ASCII数据形式提供。基于国际地磁参考场模型（IGRF），只有当航天器坐标系中的三个离子速度均可用且质量良好时，数据才会转换为磁坐标系。