This questions related to GNSS (GPS, Glonass, Galileo) reached me.
Q: “I work for a company that develops GPS tracking devices. I have been reading your posts on M2M and you seem to be an expert regarding GSM/UMTS/ETC and GPS. There are two questions I want to ask you. Number one is with Galileo, you seem to be really excited about this mixed modules. Are the costs the same? Is the precision really that good? Do you have any suggestions as where to begin?”
A: I am 25 in radio communication and 15 years in GSM and GPS. I also was the leader of a team to develop tracking devices with and without GPS. In year 2000 at EXPO in Hannover all salesmen for tickets of gondola train was monitored by a GSM based locating system. We were able to track indoor.
Right now there is no Galileo active. I assume you mean Glonass. The combination on GPS with Glonass gives you a better accuracy and also a better probability to catch a satellite signal. The test trip in Dallas shows the difference very good. The single GPS module has received 4 to 8 satellites during a trip between the skyscrapers. If you have a closer look on the picture, then you will see that there are parts in the track, where the GPS module has given no latitude and longitude. Other parts of the track show the car driving in the buildings. If the GPS module gets only 4 GPS satellite signals, then it has worst case to use reflections for the calculation. The result is a wrong position.
The opposite you see at the combined GPS/Glonass module. The minimum visible satellites on sky were 8. Best were 12. Anyhow if the combined GPS/Glonass modules can choose 4 out of 8 or 5 out of 8 satellites then it can ignore signals that are reflected and poor.
Back to Galileo: Galileo you will get by firmware update. The GNSS module is able to receive GPS, Glonass, Galileo and even the Chinese satellite GNSS called Compass by updating the firmware. See also:
- Test trip with single GPS and combined GPS/Glonass module
- GPS was yesterday, Glonass is today and Galileo is tomorrow
Nevertheless, if you still have further questions and would like to start the development of your own GNSS application right now then just send an e-mail to harald.naumann (at) gsm-modem.de or use the form here. I will be glad to share my experience and knowledge with you.