Aerospace Instrument-Making Annotation << Back Issues of Building an Adaptive System of Tracking and Detecting "Stealth" Objects in the Infrared Range Alieva G.V. The problem of adaptive control of the detection and tracking system of stealth aircraft is formulated. To solve the problem by the method of variational optimization, it is proposed to introduce a function of focal length control depending on the atmospheric transmittance. Under the condition of imposing some restrictive condition on this function, the problem of unconditional variational optimization is formulated, the solution of which gave a specifi c form of this function, at which the studied target functional reaches a minimum. It is indicated that such a minimum can signifi cantly complicate the performance of the detection operation and a recommendation is given to avoid the specifi ed detection mode in practice. Keywords: optimization, adaptive control, functionality, detection, infrared range. DOI: 10.25791/aviakosmos.3.2025.1469 Pp. 60-64.