Task: Translation
Input (Japanese): 著者等は、また、軍用機の活動はその当時激しかったが、レーダー記録は未知の物体に対し明らかな動きを見せなかったと結論づけた。
Output (English): The authors also concluded that military air activity was heavy at the time, but that the radar records show no overt action toward the unknown object.