C/N0 Readings Above 50

[Steven Hills]

Hello Folks,

A question to the group.

• It was my understanding that C/N0 maximum values from the satellites was a value of 50 max.  
• I was doing some accuracy testing and was getting values above 50! 
• Have the newer satellite changed in terms of power output for these readings?
• I've scrounged around he web and couldn't find any explanation or details of what/why this might be
• I am using a Samsung Galaxy A53 with the latest version of GPSTest.

I have attached a couple of screenshots.

TIA 
Steven

[Invalid Data]

There could be something wrong with Android auto gain control.

GNSS transmission power should remain unchanged because it's a standard specification in SIS ICD.

But in some case GPS satellite have the ability to boost signal power when conducting a military operation. Which could affect the receiver.

Specifically, the L2 band, Is often increased by 3db-5db. This happened in April 2018 and June 2019. But I don't know if there was any L1 band anomaly. 

Technically Every GNSS constellation have reserved ability to boost signal power when needed. But this rarely happens in Galileo/BDS. (I'm hoping it would never happened, 🕊️)

But then again, SIS ICD only documents the minimum power, and no maximum power is specified. 

Some receiver is quite unhappy about higher power gain, while others may be just fine. 

Steven Hills <hillsst...@gmail.com> 于 2023年11月22日周三 上午7:33写道：

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[Sean Barbeau]

Steven,

Thanks for the info! This sounds like a bug to me.

Could you please open a ticket at https://issuetracker.google.com/issues/new?component=313183&template=0 and attach a bug report (https://developer.android.com/studio/debug/bug-report#bugreportdevice)?

Thanks,

Sean

[Steven Hills]

thanks this seems a very plausible explanation and your graph illustrates  on the L2. What was the software you have used to generate graph? It would be interesting to look at my collection time Friday November 17th, 2023 09:15 to 09:30 CST

[Invalid Data]

It came from a blog post on Chinese social website

https://www.secrss.com/articles/11549

https://www.zhihu.com/tardis/bd/ans/369350230

You can read  them with google translate