Research For Aircraft Detection And Hit Susceptibility Analytical Method In The System-of-Systems Warfare

The high survivability design of the military aircraft is one of the most important considerations in the modern aircraft design.The aircraft survivability is divided into two parts:susceptibility and vulnerability.The research of susceptibility focuses on the hitting characteristics by the threats,including detection,identification,tracking,fire control,guiding and hitting,which is relevant to the object feature signals,electronic counter measure equipment and tactics.The research of vulnerability focuses on the damage characteristics when the aircraft is hit by the threats.In this paper,the aircraft susceptibility in the detection and hitting stage is researched.The traditional method and model to analyze and assess the aircraft susceptibility is suitable to the small group of combat,by which the RCS signal,infrared signal,radio-frequency signal and the electronic counter measures of the aircraft can be researched.The modern warfare is the confrontation between the system-of-systems which has a high demand for the information sharing.Datalink is an important tool to achieve the goal of information sharing between each combat unit.As a result,in this paper,the aircraft susceptibility will be assessed in a system-of-systems combat environment with datalink by building the offensive system and the defensive system.After this,the methods and models to analyze and assess the aircraft susceptibility will be improved.The main contents of this paper are as follows:1.The system-of-systems combat framework model to analyze the aircraft susceptibilityBy simplifying the assessing process,the aircraft susceptibility is divided into two parts:the feature signature susceptibility such as RCS signal,infrared signal and radio signal;and the electronic counter measure susceptibility,such as infrared flares,active deceived jamming and passive chaff jamming.According to the definition of system-of-systems,the framework of combat model contains four parts:combat module,command and control module,datalink module and environment module.The combat module carries out a specific combat process.The command and control module makes a decision by the information collected from the whole battlefield.The datalink module transmits and shares the information between the combat units.The environment module describes the whole battlefield environment.In this section,the contents of aircraft susceptibility are illuminated,and the framework model of system-of-systems combat is built which will be the foundation for a more specific and detailed research in the latter paper.2.The assessment of aircraft feature signature susceptibility in a defensive system modelAccording to the system-of-systems combat framework model,a method to assess the aircraft feature signature susceptibility in a defensive system composed of detection system,tracking system,air defense system,command and control center and datalink is proposed.The detection system will use two kinds of detection systems to detect the aircraft:the radar detection system and the radio detection system.The tracking system will obtain the orientation and coordinates of the object aircraft by the extended Kalman filtering algorithm.The air defense system is divided into long-range attacking system,middle-range attacking system and short-range attacking system which consists of aircrafts and missiles.The command and control center has two tasks:one is calculating the combined detection probability of the detection system;the other is guiding the air defense missile attacking the object aircraft.The simulation results show that:(1)in the system-of-systems combat condition,the detection ability of the defensive system has enhanced more than 10%.As a result,the traditional way by decreasing the feature signature will not be useful for an aircraft to be invisible in front of a defensive system.The aircraft should decrease the detection probability by the electronic countermeasures,mission–flypath optimization and the application strategy of the onboard devices.(2)When the datalink is better,a longer infrared locking distance is needed by the attacking system.As a result,decreasing the infrared signature of the aircraft can decrease the infrared locking distance and then decrease the kill probability by the threats.(3)During the tracking and attacking process of the defensive system,the performance of datalink has a significant influence on the battle result.For example,when the time delay of datalink decreases from 600ms to 60ms,the tracking error can decrease 90%;in the attacking process,when the time delay of datalink increases from 300ms to 900ms,the guiding time will decrease 61%;when the time delay of datalink increases from 0ms to 200ms,the miss distance of the missile will increase from 10m to 43m.3.The assessment of aircraft susceptibility when the offensive system implements the electronic counter measuresAccording to the system-of-systems combat framework model,an offensive system model is built to assess the aircraft electronic counter measure susceptibility in this section.There are two situations when the aircraft implements the electronic counter measures:within the formation and there is no command and control center;within the offensive system and there is a command and control center.When the electronic counter measure is implemented within the formation,the aircraft will receive the threat's information from the friend aircraft of the same formation and then implement the electronic counter measure.But when in the second situation,the implementing time of the electronic counter measure is decided by the people of the command and control center.The decision model is built by the multi influence diagram algorithm.The performance of datalink will affect the work load of the people in the center and the decision will also be affected.The result shows that:(1)the jamming effect of the active deceived jamming will be better if the jamming is implemented earlier.Besides,when the performance of the datalink increase from 0s to 2s,the jamming distance will decrease from 15km to 13km and the miss distance of the missile will decrease from 320m to 70m.(2)When deploying the infrared flares,there is an effective deploying section.When the infrared flares are deployed in this effective deploying section,the electronic counter measure will be effective.When the flares are deployed too early or too late,the electronic counter measure will be useless.(3)When the datalink performance is better,the decision made by the command and control center will be more optimal and the aircraft will have a higher combat survivability.4.The research of the unit trajectory control to decrease the aircraft susceptibility in a system-of-systems combat environmentAccording to the defensive system model and offensive system model,the unit trajectory control models in the system-of-systems combat by the command and control center are built.The unit trajectory control models contains two parts:combat task allocation and combat path planning.Firstly in this chapter,a precise combat model based on the kill probability spectrum is built by the aircraft feature signature susceptibility and the aircraft survivability calculation formula.The combat model will be the foundation for the task allocation and path planning.In the aspect of task allocation,the“Acceptability-Rejectability”algorithm based on the sales contract is used to allocate the tasks in real time even when there is an emergency in the combat.Besides,the effects brought by the performance of datalink and aircraft electronic counter measures are also analyzed.In the aspect of path planning,a VS-SAS path planning algorithm based on the crossing aisle is proposed for the path planning.And the aircraft feature signature susceptibility and the electronic counter measure susceptibility are all analyzed.The simulation results show that:(1)in the aspect of task allocation,when the time delay of datalink is less,the jamming effect of the active deceived jamming will be better which will minimize the passive effect caused by the emergency and a better task execution sequence can be obtained.(2)In the aspect of path planning,a low aircraft feature signature and electronic countermeasures can decrease the average kill probability of the path and then an optimal fly path is obtained.For example,when the RCS of the aircraft decrease from20m~2 to 3m~2,the length of the path will decrease 12%and the average kill probability of the path will decrease 81%;when the chaff electronic counter measure is implemented,the length of the path will decrease 6%and the average kill probability of the path will decrease 19%.5.Aircraft susceptibility contrastive analysis between two aircrafts in a system-of-systems combat environmentThe aircraft susceptibility is divided into two parts:feature signature susceptibility and electronic countermeasure susceptibility.Two aircrafts with different design level of aircraft susceptibility are used to make a comparison.One aircraft has a suppression design of RCS,infrared signal and radio signal,multiple electronic counter measures and high performance datalink.The other one doesn't have a suppression design.It has a few electronic counter measures and a general performance datalink.After analyzing the distribution of kill probability spectrum,the results of real time task allocation and path planning,the conclusion can be obtained that:the low aircraft susceptibility design can improve the aircraft combat survivability significantly and is very important to the aircraft design.In this paper,the characteristic of modern system-of-systems warfare is analyzed.The datalink model is the clue and the aircraft susceptibility model is the base of the full paper.By building the defensive system model,the offensive system model and the unit trajectory control model,an aircraft susceptibility assessment framework model is built.With the multi detection system model,extended Kalman filtering model,missile guided model,command and control center decision model,real time task allocation model and real time path planning model,the aircraft susceptibility is assessed and analyzed and the importance of the low aircraft susceptibility design has been revealed.At the meantime,an aircraft real time task allocation and path planning software using C/C++is developed.