How do Teseo-LIV3FL determines which sats to use for tracking?

[AFidi.1]

Below is a screenshot from Teseo-Suite for my Teseo-LIV3FL GNSS Module

Lighter flag color means the satellite is not used. As you can see GPS satellite with PRN 16 has higher SNR (23dB) than PRN 9 (21dB) which means the signal quality should be better than the PRN 9, but in this case the module uses the PRN 16 instead.

Why did this happening and how the Teseo-LIV3FL module choose which satellite it'll use?

[Tesla DeLorean]

Anything below 32 dBHz is pretty poor.

Usually satellites are excluded based on their relative performance vs the best solution. The receiver computes a residual, it is apt to be larger on poorer measurements.

The signal strength can relate to the distance the satellite is away from the receiver, and perhaps if the signal reflects off nearby surfaces.

[AFidi.1]

Hi,

Do you have any literature or reference that discuss more about the 32 dBHz minimum?