  We demonstrate an atom interferometer measurement protocol compatible with
operation on a dynamic platform. Our method employs two open interferometers,
derived from the same atomic source, with different interrogation times to
eliminate initial velocity dependence while retaining precision, accuracy, and
long term stability. We validate the protocol by measuring gravitational tides,
achieving a precision of 4.5 {\mu}Gal in 2000 runs, marking the first
demonstration of inertial quantity measurement with open atom interferometry
that achieves long-term phase stability.
