A system and method is provided for tracking and maintaining a highly accurate inventory of shipping containers that are stored within container storage facilities. The invention includes using multiple complementary real-time and post-processing positioning techniques associated with various positioning sensors that are associated with inventory pieces or equipment. Examples of such positioning techniques are DGPS, GPS with RTK, DGPS loosely-coupled with INS, DGPS tightly-coupled with INS, and DGPS deeply-coupled with INS. Data correction and fusion techniques are applied to these positioning stages to re-compute a calibrated position with an improved accuracy. An additional trajectory can be iteratively determined using the fusing technique until the position data becomes statistically trustworthy. Further, combinations of multiple real-time positioning techniques combined with past position error correction algorithms provide a high accuracy needed for inventory tracking.