[recharged93]

I thought of snr as a trigger, and sensitive to design-- it accounts for antenna setup, thus different for every phone.

Why not use HDOP, VDOP? It's a better inidication of how off you really are (likely within CEP). Pretty much every new drone AHRS uses DOP values vs snr...

[jhayward]

the various DOP values assume there are no local obstructions. This method attempts to take in to account the local environment and determine which satellites may be obstructed. DOPs can't help with that.

[gpsGuys]

Yeah, exactly. DOP can provide an artificially rosy picture of the satellite geometry and visibility when you have clean reflections that looks like LOS satellites.