Bye, bye GPS – Welcome Glonass

This week I was visiting customers to present the latest GNSS modules. These hybrid GNSS modules are able to receive GPS and Glonass satellites in parallel. We received 17 channels. Just have a look at the video (37 sec).

• Dark blue bars = GPS satellites with fix
• Light blue bars = Glonass satellites with fix
• 1 orange bar = GPS satellites without fix
• 1 red bar = Glonass satellites without fix

In Paris we were able to receive 21 channels in parallel. Anyhow, worst case you “see” 3 GPS and 1 Glonass, 2 GPS and 2 Glonass, 1 GPS and 3 Glonass or 0 GPS and 4 Glonass satellites at the sky. Without Glonass you will not be able to locate anything. A good example was the beginning of a war. Rumours tell that we got 5 hours no GPS fix in Europe.

The selection of the right GPS module with the right A-GPS concept and the right power save mode is a decision that will change the power consumption and the standby time of your device dramatic. Is it a single GNSS module that supports GPS only enough or is it better to use a hybrid GPS/Glonass module? Makes it sense to use A-GPS? Is the use of 1-axis gyro, 3-axis gyro, accelerometer, pressure sensor, magnetometer and Odometer interface useful or not? Makes it sense to develop a prototype with 1-axis gyro, 3-axis gyro, accelerometer, pressure sensor, magnetometer and odometer interface and after the test to decide which sensors will help to get the best indoor positioning? Will one of the five different power save modes be helpful, and which out of five is to select? Is an A-GPS by A-GPS-server, self assisted A-GPS or A-GPS on demand the better solution? What type of antenna is to select: directional GPS patch antennas with right hand polarisation, non polarised GPS chip antennas, single ended GPS helical antennas or better a ground plan independent helical with balun to minimise the effect of human body? Shall we trust one GNSS system like GPS or is it saver to use a hybrid GPS/Glonass modules?