Building a defender's 3D program path in an ADT game with incomplete a priori target information

This paper is devoted to an Attacker–Defender–Target (ADT) game in the 3D space. The Target makes flat circumferential movements with a constant velocity. The Attacker moves uniformly and rectilinearly from an arbitrary point in the upper hemisphere. The distinctive feature of the problem statement is that the Target has an onboard mobile Defender. The Defender is intended to intercept the Attacker's possible paths dangerous to the Target (in the pointwise meeting sense). This task is complicated since the Target and Defender do not see the Attacker during the movements. They know only the initial bearing; the current bearing and the initial and current distances to the Attacker remain uncertain. For this reason, the Target and Defender are assumed to move along a program path.