A testing system is described. The testing system is adapted to evaluate navigation systems. The testing system includes: a recording system adapted to collect and record signals received and interpreted by a navigation system during field operation; a time-synchronized database adapted to receive and store data representing the signals collected and recorded by the recording system: wherein the stored data is able to be used to test operation of one or more navigation systems under test. A method of testing navigation systems includes: gathering data that would be received and interpreted by a navigation system during field operation, wherein the gathered data includes data associated with received radio signals; storing gathered data in a time-synchronized database; and using the stored data to test the operation of one or more navigation systems. A system adapted to test navigation systems includes: a recording system; a playback system; and a simulation system.