Formation velocity 3000 m/s

Velocity error ±100 m/s

Velocity error ±200 m/s

Velocity error

±300 m/s

Before the drill bit 100 ms

150 m

±5 m

±10 m

±15 m

Before the drill bit 200 ms

300 m

±10 m

±20 m

±30 m

Before the drill bit 500 ms

750 m

±50 m

±100 m

±150 m