How We're Different
Received signal strength falls off with the square of distance. GPS transmits from medium Earth orbit, roughly 20,200 km up. Lightyear transmits from low Earth orbit, twenty to forty times closer to the receiver. Our signals are 25x stronger at the Earth's surface than existing GPS, and that extra power is what keeps a receiver locked through interference, foliage, and space weather events.
The civil GPS signal carries no authentication. Its structure is public, so any transmitter can generate a convincing copy, and a receiver has no way to tell the real signal from a forgery. Our signal is authenticated and encrypted: a receiver verifies that what it is tracking came from Lightyear, and a spoofer that can't produce a valid signature can't impersonate one.
Conventional GNSS lives entirely in L-band, a narrow slice of spectrum that makes it straightforward to target. One jammer covers every constellation at once. Our signal transmits outside L-band, so interference aimed at GNSS doesn't reach it, and a receiver holding both has two independent sources to cross-check.
GPS flies at 55° inclination, so no GPS satellite ever passes overhead above that latitude. Near the poles the whole constellation sits low on the horizon, where geometry is worst and terrain blocks most of what's left. Lightyear flies across many planes, including high-inclination and polar orbits, so receivers at the poles get signals from overhead instead of on the horizon. As melting ice opens the Arctic to shipping, patrol, and survey traffic, that is exactly where coverage is thinnest today.
Solar flares and geomagnetic storms disturb the ionosphere and scintillate the signals passing through it. GNSS is especially exposed: its L-band signals sit at a frequency the ionosphere bends and scatters easily, and a receiver can lose lock entirely when it turns turbulent, most severely near the poles and during solar maximum, with no warning before the outage starts.
Ionospheric scintillation falls off sharply with frequency, and Lightyear transmits well above L-band. The same higher frequency that keeps our signal outside the reach of conventional jammers also makes it far less susceptible to the scintillation that disrupts GPS, so a receiver holding both has an independent signal when space weather takes GNSS down.