RT_GPS_Vel_ECEF_2 Y and Z velocity

RT_GPS_Vel_ECEF_2: 140, 20 (0x8C1420 + unit id) (0x314)

Byte 0: Validity

Bytes 1-3: ECEF Velocity Y (m/s)

Bytes 4-6: ECEF Velocity Z (m/s)

Byte 7: Unused

ECEF velocities are velocities in the Earth-Centered Co-ordinate Frame.

Speed resolution is m/s * 1e-4