gmrple·2 lata temu·discussGravity map matching is an approach that can provide absolute references, the general problem there is that gravity maps are not good enough.
gmrple·2 lata temu·discussNo, this is about preventing unwanted jamming/interference by a transmitter on frequencies it isn't intending or needing to transmit on as part of the design phase of a product. Overcoming intentional jamming is an entirely different ballgame.