Inertial Reference Units (IRUs) are the basic reference for a precision pointing system. These units must provide an
inertially stable light source to be used as the reference to align the outgoing laser beam and to reject beam train jitter
due to vibrations. The IRU will be subjected to 6 degrees of freedom motion during operation. The correct operation of
an IRU requires it to measure the angular motion and not be affected by the linear input vibration. Testing of these units
is difficult, since the vibration input motion may be perfectly correlated between the angular inputs and the linear inputs.
This correlation makes it impossible to separate the angular and linear IRU responses during a test, even with perfect
measurements of the input vibrations. The solution to this problem is to obtain a vibration test station that can provide
linear motion without any angular motion, and angular motion without linear motion. This paper will describe the
evaluation of the test tables and show test data from an IRU that indicates how these tests can be beneficial in identifying
Boeing-SVS Inc. has developed a small, inexpensive inertial measurement system that provides a two-axis optical inertial reference for a variety of optical pointing and tracking system applications. The design combines two distinct innovations. The first is the realization of a fully functional commercial off-the-shelf (COTS) system, and the second is the miniaturization of the sensing assembly and support electronics.