An Inertial Navigation System (INS) testing system includes a Unit Under Test (UUT) with an INS module, a DAT tool configured to provide command and control functions to a user, and a Dynamically Integrated Navigation Tester (DINT) in communication with the UUT and the DAT tool. The DINT includes a truth data conversion module configured to receive truth data and convert it to navigation data suitable for transmission to the UUT. The INS testing system advantageously allow a user to interface with a UUT while providing user-specified dynamic inputs from the DINT with the truth data selected by the user.