Analysis of LEO satellite constellation for positioning

As the technology develops, many companies and organizations started or planned to build low earth orbit (LEO) satellite systems for communication service, such as high-speed internet coverage. These satellites are usually small and light-weighted. Meanwhile, with the 5G and autonomous driving systems coming soon, as well as more and more smart devices entering the market, global navigation satellite system (GNSS) has become a crucial part of people’s daily life.

A novel way to combine both fields is to use these LEO small satellites for positioning by adding a few essential payloads. To fulfil this purpose, the distribution of a LEO mega constellation must be designed in the way that it could be used not only for communication, but also for positioning. Since most of the traditional GNSS satellites are in the medium earth orbit (MEO), which has different characteristics compared to LEO, the conditions and criteria for parameter selection must be redesigned. This study tries to discuss and determine some important parameters in LEO mega constellation design.

In order to get a uniform distributed constellation around the world, as well as a relatively low dilution of precision (DOP), by analyzing, it has been shown that a combined constellation with two sets of satellites in different altitudes and inclinations is better than a single constellation. Further study has estimated and discussed the proper parameters for the combined constellation, such as number of satellites, number of orbital planes, inclination, orbital height, etc. Other geometry factors like distribution and DOP will also be discussed.