Trajectory control methods for observation in two-position angular airborne radio monitoring systems Part 1. Orthogonal methods
Authors: Merkulov V.I. , Milyakov D.A. , Khar’kov V.P. , Chernov V.S. 
Published: November 2021

Formulation of the problem. Currently, much attention is paid to the practical application and further improvement of two-position goniometric systems (TPGS) airborne radio monitoring, the advantage of which over single-position systems is the possibility of almost instantaneous determination of the location of the radio emission source (RES). A feature of the operation of the TPGS is the dependence of the errors in the positioning of the RES on the «geometry» of the system, i.e. on the size of the base and the position of the RES relative to the base. That is why the problem of optimizing the mutual arrangement of the receiving positions and RES is very urgent. To minimize positioning errors, two groups of trajectory observation control (TOC) methods have been developed, which is due to the variety of conditions for the practical use of aviation goniometric two-position systems and different degrees of their effectiveness. The first group of methods, called orthogonal, provides control of the receiving positions placed on the aircraft, so that the lines of sight of the RES relative to them intersect at right angles. The formation of a right-angled triangulation triangle, at the vertices of which the aircraft and RES are located, can be ensured by appropriate movement of the information support aircraft, or by simultaneously pointing both aircraft. In the first case, it is envisaged to output the information aircraft to an arbitrary point of a straight line, orthogonal to the line of sight «leading aircraft-RES», during the flight along which the best conditions for observation are created, or to a given point on this line. The second group of TOC methods ensures the minimization of errors in the positioning of radioactive sources at each current moment of time. When developing the corresponding trajectory control algorithms that implement the indicated trajectory control methods, direct and indirect optimization methods were used. To date, various TOC methods have been developed, but there is no systematic presentation of them. Purpose. To give a systematized idea of the developed methods of trajectory control of observation in two-position goniometric systems for radio monitoring of the surrounding space, as well as ways of solving the problem of ensuring the best observation conditions and increasing the accuracy of estimating the phase coordinates of the RES in these systems. Results. In the first part of this article, orthogonal methods and algorithms of TOC are considered, the implementation of which contributes to a significant increase in the accuracy of estimating the coordinates of the RES in goniometric two-position airborne radio monitoring systems. Information on the results of experimental studies confirming the effectiveness of the developed TOC methods is also given. Practical significance. The areas of practical application of various TOC methods in solving radio monitoring problems are shown, information about which can be used when choosing rational trajectory control methods for specific conditions of practical application, as well as when developing new TOC methods.