ako mislis na ovo sto ovaj echo prica za gps, nisam siguran da shvatam o cemu govori nadam se da on zna o cemu prica ja mogu samo pretpostaviti da nije shvatio da promjena faze vala moze putovati brze od svjetla, ali ona ne nosi nikakvu informaciju/energiju \"Previous research has demonstrated that a single frequency L Band signal that traverses the ionosphere will arrive slightly earlier than it would have if it were traveling through a vacuum. This does not violate any relativistic principles since no information is conveyed by just a single frequency. The time advance is a function of frequency, and to first order, is equal to k/f^2. It turns out that the information conveyed on a modulated L band carrier, arrives late (group delay) by exactly the same amount of time that the carrier arrives early.\"