Ju.P. Mel-nikov

Typical actions in modern military conflicts are group. Thus, the structure of groups of fighting objects (the ships, flying devices, etc.), as a rule, includes carriers of stations of jamming (CSJ) to means of detection. With reference to sea objects such CSJ the typical fighting ships equipped with means jamming, with reference to flying devices - special planes (for example, such as ЕА-6В «Prouler» for creation of jamming mainly from the set zones which are taking place on a significant distance from covered groups) or such as ЕА-18G «Grouler» (for creation of jamming mainly from fighting groups of flying devices). Before an aviation information complex the task of investigation (detection, recognition, definition of coordinates and parameters of movement) groups of objects in structure of which there are carriers of stations of electronic jamming is put. Investigation of each object is necessary for performance of this task in group and development of the decision on type, coordinates and parameters of movement of group, as single whole. The technique of an estimation of its efficiency is necessary for quantitative estimations of quality of the decision of this task. In article information means of the big distances (close to radiohorizon)  a radar station and station radio engineering investigations (REI) are considered(examined). Investigation of group targets will consist in definition of number and a relative positioning of objects inside group, its assignment (shock, demonstration, false). For onboard radar investigation compact, removed on the range, close to radiohorizon, the group targets is objectively a challenge as their angular sizes appear comparable with a width of the main beam modern aviation radar ststion. In absence of the organized radar jamming insufficiency of the angular sanction of objects is compensated by the high sanction on range, and investigation of the group targets (definition of number of objects in group) is carried out successfully. If by one or several ships of group stations of active jammer the sanction on range is practically excluded work. In conditions the ECM rather effectively application of a known measure  indemnifications on the corners, consisting in formation of «zero» in the diagram of an orientation of the aerial in directions on CSJ. For the approached estimation of its efficiency in a technique a number of assumptions, and also the found distribution of angular distances from a direction on any object of group and on CSJ is used. As a result of calculations it is received, that efficiency of investigation of the group sea purposes on the big distances is insufficient even for radar with the narrow diagram of an orientation and deep indemnification of software which are taking place on angular distances, big width of main beam radar. Thus, at the big distances and absence in onboard radar indemnifications of CSJ near to the main beam of the diagram of an orientation of the aerial, radar-tracking investigation of the group targets has small efficiency, increase of her is possible at use of onboard station of REI. At investigation of the group purposes on big distances the station of REI using a mode of reception of reflected signals working ship radar of the circular review that allows to determine quantity of objects in group including onboard what there are no working sources of a radio emission has the greatest efficiency. The developed methodology of an estimation of efficiency of investigation of the group targets covered CSJ, taking place inside group, allows to carry out quantitative estimations of conformity of onboard active  passive information means to tasks in view in various phono-target conditions. The examples of calculation resulted in article illustrate its applicability and have also applied value.