What is ISO 16698 - Geomagnetic activity about ?
ISO 16698 is one of the three international standards that deal with earth magnetic fields. ISO 16698 discusses the future geomagnetic activity.
ISO 16698 specifies the methods used for estimating geomagnetic indices for time intervals ranging from short-term (hours to a few months) to long-term (months to years).
ISO 16698 is intended for use to predict future geomagnetic indices and space environments.
Who is BS ISO 16698 - Geomagnetic activity for? 
 BS ISO 16698 on methods for estimation of future geomagnetic activity is useful for: 
- Space researchers
- Seismologists
- Geologists
- Magnetic field testers 
Why should you use ISO 16698 - Geomagnetic activity ?  
Geomagnetic indices describe the variation of the geomagnetic field over a certain time period and provide a measure of the disturbance of the magnetosphere. These indices can be used to estimate upper atmospheric and plasmaspheric densities and many other space environment models.
ISO 16698 provides guidelines for specifying the process of estimating future geomagnetic activity. They are also used as the input parameters for orbital lifetime prediction and worst-case environment analysis of electrostatic charging. 
The accuracy and method of predicting geomagnetic indices depend on the time scale of prediction. ISO 16698 presents existing works based on three categories of time scale:
- Short-term prediction (1 h to a few days)
- Middle-term prediction (a few weeks to a few months)
- Long-term prediction (half a year to one solar cycle
These are required as input parameters for the magnetospheric magnetic field (ISO 22009), upper atmosphere (ISO 14222), ionosphere, plasmasphere (ISO 16457), magnetosphere charged particles and other models of the near-Earth space environment. They also serve as the input parameters for orbital lifetime prediction and worst-case environment analysis of electrostatic charging.
What’s changed since the last update ? 
BS ISO 16698:2019 supersedes BS ISO 16698:2013, which is withdrawn. The main changes in BS ISO 16698:2019 compared to BS ISO 16698:2013 are as follows:
- Addition of 5.9 and 5.10
- Update of reference lists of Clause 6
