The present disclosure relates to a computer-implemented method. The method includes: receiving a first metric of a first object; receiving a second metric of a second object; calculating a distance between the first object and the second object based on the first metric and the second metric; comparing the calculated distance with a predetermined distance; identifying whether the second object is approaching the first object based on the first metric and the second metric; calculating an elevational difference between the first object and the second object; and generating a notification responsive to the calculated distance being less than the predetermined distance, the second object being identified as approaching the first object and the calculated elevational difference between the first object and the second object being less than a predetermined value.