GALILEO/OSNMA, stability of measurement

[Aron Szabo]

Dear Members,

for getting a full GALILEO/OSNMA cryptography layer we need to receive raw dump of signals for apprx. 600 sec. This requires high stability of measurement equipment and environment. (The software layer - GPSTest - seems to be good for this but we have questions regarding to hardware layer. So, sorry for offtopic, but I assume that members here have experience in such topics as well.) We have made tests with a u-blox M10 module and also with BCM47755-based Xiaomi Mi 8 mobilephones but it seems that achieving such level of stability is nearly impossible. So, it is a question to us whether simple mobilephones or small IoT-s of human users are capable to build operation logic on OSNMA-layer of GALILEO signals.

However, we have seen galmon.eu site (https://galmon.eu/observers.html) where u-blox "ZED-F9P" is mentioned with antenna (probably "ZED-F9P-05B") and also recently (2024-09-02) published GSC Europe test report mentions that 600 sec traffic dump with ADKD0 for all satellites (SV) had a 96% availability (https://www.gsc-europa.eu/sites/default/files/sites/all/files/OSNMA_Status_after_completion_of_testing_activities.pdf). But there is no detailed information about measurement equipment.

So, do you know anything about measurement equipment? What modules are exactly used? Do they apply other accessories (e.g. antenna)? And if so, what are parameters of those accessories (e.g. antenna length/size)?

Best regards,
Aron

[Sean Barbeau]

Hi Aron,

If you're testing on Android phones, have you enabled force full GNSS measurements?

See https://barbeau.medium.com/gnss-interrupted-the-hidden-android-setting-you-need-to-know-d812d28a3821.

The latest version of GPSTest should force this in the app itself but it doesn't hurt to enable the system setting to be sure.

Thanks,

Sean

[Aron Szabo]

Hi Sean,

thanks for the hint! I have missed that! OK, I have enabled "Force full GNSS measurements" on Xiaomi Mi 8.

On the other hand: does anyone have experience with GALILEO antennas? I have seen 25x25 mm and also one with diameter of 90 mm. How much do they improve the loss rate at open sky conditions?

BR, Aron