Burst Timing Offset (BTO) is one of the most important pieces of evidence in understanding what happened to MH370. It measures how long it takes for a signal to travel from the aircraft to a satellite and back to a ground station. That time delay—measured in microseconds—reveals distance.

Think of it like radar or a bat using echolocation. A signal is sent out, it travels through space, and when it returns, the system records how long the journey took. The longer the delay, the farther away the aircraft is from the satellite.

But BTO doesn’t give us a single location.

Instead, it gives us a range.

Every possible point that shares the same distance from the satellite forms a circular arc across the Earth’s surface. These arcs—known as the “handshake rings”—became the foundation of the MH370 search.

Each time the aircraft communicated with the satellite, a new BTO value was recorded. Each value created a new arc. When placed in sequence, these arcs form a corridor—a narrowing path that the aircraft must have followed.

This is where the real work begins.

BTO tells us where the aircraft could be, but not exactly where it is.

To refine that path, we combine BTO with other signal behaviors—especially frequency (BFO)—and apply aircraft motion, timing, and physics.

In this gallery, you’ll see how we take these arcs and turn them into something more precise—step by step—moving from raw signal timing to a defined and testable flight path.

Because what started as simple timing…
becomes a map hidden inside the signal.