The measurement of the close time is the key task of planning the time-sensitive target kill chain（TSTKC）. Ignoring the overlapping relationships among the steps of TSTKC， previous studies have adopted methods based on linear accumulation. This paper proposes a dynamic measurement method for the close time of TSTKC based on overlapping relationships additionally. Simulation results show that this method is more accurate， which is helpful for the command organization to capture more strike opportunities. The method also adapts to the changes of the window of vulnerability， which can provide a theoretical basis and technical support for the construction， modelling and effectiveness evaluation of TSTKC.

Aiming at the problem that radar is easy to be damaged when being attacked by HPM weapons， this paper theoretically analyzes the relationship between the farthest protection boundary to antenna gain and receiving front-end limiter’s capability， and compares the capability of reflector radar and active phased array radar against front door coupling attack from the perspective of spatial filtering. The analysis shows that only when the HPM weapon is near the main lobe range of the reflector radar antenna， its front door coupling attack effect is stronger than that of the active phased array radar； on the contrary， it is weaker than active phased array radar. Because the main beam of the reflector antenna radar is very narrow， the attack time window is very short， so the reflector antenna radar has stronger protection ability when facing HPM weapons.