Title: Satellite Navigation (SatNav): What is GNSS | GPS | GLONASS | QZSS
Headings: What Is A Satellite Navigation System?
What Is A Satellite Navigation System?
Global Navigation Satellite System (GNSS)
List of satellite navigation systems of various countries
Navigation Message
Receiver Independent Exchange Format (RINEX)
Conclusion

Content: RINEX has three versions—RINEX version 1, RINEX version 2 and RINEX version 3—the latest of which is the RINEX 3.03, which is an upgraded version of RINEX 3. Now, one might think that with so many different satellite navigation systems, it would be difficult to differentiate between them and classify them accordingly. Let’s explain this by taking an example of navigation messages (both are in RINEX-3.03 format) from two different satellite navigation systems: So, can you tell which satellite navigation system the above navigation messages belong to? If not, don’t worry, we’ll decode it together. The first one is from Galileo, whereas the second is from the Quasi-Zenith Satellite System. If we take a closer look at the start of the message and ignore the rest, we see that the message begins with ‘E’, which represents European Union, whereas the second message starts with ‘J’, which represents Japan. We know that different satellite systems send different navigation messages encoded accordingly, so to decrypt them, we first need to know how to differentiate and identify the given message and must use certain algorithms to decode them (usual concepts of a data structure are used). Now, coming back to our question on Google Maps, which uses GPS as its navigation system. The user sends the signals to the satellite through his/her device asking for directions to a certain destination.