  In the plane wave spacetime, we find that there will be a precession angle
deviation between two free-falling gyroscopes when gravitational waves passed
through. This kind of angle deviation is closely related to the well-known
standard velocity memory effect. Initial conditions such as the separation
velocity or displacement between the two gyroscopes will affect this angle
deviation. The evolutions of the angle deviation are calculated for different
cases. We find that in some extreme circumstance, the angle deviation's order
of magnitude produced by a rotating compact binary source could be $10^{-14}$
rads. Therefore, this memory effect caused by the gravitational wave is likely
to be detected in the future.
