Model along track kinematics equation of the aircraft by referencing to a classical conclusion that the along track error of the aircraft is normal distributed,consider an encounter between two aircrafts at the same flight level,construct an ellipse conflict region. By establishing a Caresian coordinates represented aircraft position appropriately. First,propose a probability estimation algorithm of medium term conflict detection for cross routes at the same level,then analyze the relationship between the conflict probability and several factors based on various graphs. The results show that when applying the algorithm to the conflict detection whose look ahead time is 15 minutes to 20 minutes,it can achieve perfect effects;under the same condition,the greater the angle between two routes is,the more precise the detection is. Meanwhile,compared with traditional randomized algorithm,the proposed algorithm is advanced in its simple calculation method,fast calculation speed and precise detection calculations. Finally,it could also be applied to the conflict detection
of multi-segment,making it is much more widely used in medium conflict detection.
