A tracking radar was used for real time flight path monitoring of ALFLEX (Automatic Landing Flight Experiment) at Australia. Calibration data, compared with position data by a laser tracker, were obtained at the first hanging flight test, and the calibration data were installed in the tracking radar. After calibration, the positioning accuracy of tracking radar was evaluated in comparison with the laser tracker in hanging flight tests. The results confirmed that the accuracy was satisfactory for real time monitoring. In addition, the accuracy was evaluated in free flight tests and the post correction data of the tracking radar were derived.