# 3D modelling of satellites around the earth

I want to find and see "GPS satellites in view" for different orbits missions. For example I want to see the observable GPS satellites for a specific satellite in GEO, for this purpose I need a software which can visualize and make a 3D model of about 33 satellites together(32 GPS satellites and one in GEO) arounding the earth for me. Do you know any special software? I use windows 8.(I couldn't use SaVi because of operating system)

• If a GPS or any GNSS satellite is "in view" of a GEO satellite, that doesn't by itself mean that the GEO satellite can receive useful signals from it. In order to keep signal strength high enough on Earth, each GPS satellite transmits almost all its power into a cone that covers the Earth below it. Only a little power "sneaks" past the earth and into space beyond Earth. From the GEO satellite's point of view, only those GPS satellites on the far side of the Earth and near its edge might provide useful signals, and then it's only the more recent ones with different side lobes.
– uhoh
May 4, 2017 at 2:30
• See this answer and this answer and images shown in the question including i.sstatic.net/mXzKt.png and also i.sstatic.net/j6frw.png
– uhoh
May 4, 2017 at 2:33
• yes, I know the difficulty of acquiring and tracking of GPS signals in GEO, But I just want to visualize it now ,and then in seperate programm I will find the observable GPS sats according to the signal amplitude and the angle of observation
– S.P
May 8, 2017 at 3:12
• OK that makes sense, the geometrical problem is one thing, the quality of the link is another. For fun you can look at stuffin.space which is also linked in this GNSS answer. Are you looking to generate a few static representations to show the concept, or do you want something that is always up-to-date? If you like Python then PyEphem or Skyfield (my favoried) can generate 3D coordinates for you. blender.stackexchange.com is all python.
– uhoh
May 8, 2017 at 4:43
• But stuffin.space has everything and is an open source project: Github Page and reading about a "real-time interactive WebGL visualisation of objects in Earth orbit" might be interesting.
– uhoh
May 8, 2017 at 4:46

Maybe Systems Tool Kit could be helpful:

https://www.agi.com/products/engineering-tools

It's a powerful tool, and there is also the possibility to have a free license, although it does not include all capabilities. I have used it on Windows 10, but I cannot tell about Windows 8.

• I've used it on Windows 7, I'm sure 8 will be fine as well. Sep 1, 2017 at 15:23

SaVi runs under Windows. It can be run under the Windows Linux Subsystem, under Cygwin, or under VirtualBox. And how to get it running is fully documented.

And SaVi includes GPS and GNSS simulations.

• Welcome to space! Feb 20, 2020 at 3:56