An analysis and research on composite modulation algorithm
This paper focuses on the problem of Doppler spread caused by high-speed target motion during coherent accumulation period for linear FM signals, then a Dual linear FM composite algorithm is proposed. The theory analysis and simulation are presented, and the conventional processing algorithm is compared with the proposed algorithm based on the echoed signal. The results shows that the composite algorithm is useful and able to be realized in engineering.
Research on Detection and Tracking Identification Algorithm of Weak Moving Target
Aiming at the features of weak moving target's detection and tracking identification technology,on the basis of introducing the difficult points of weak moving target's detection and tracking identification technology,the weak moving target's detection and tracking identification algorithm was discussed,and the detection and tracking identification algorithm was analyzed in detail according with image pre-processing,selection of target feature and target tracking,and the algorithm method and its steps were also pointed out.The simulation result shows that the algorithm is effective to identify and detect for the tracing object.All this work is significative for enhancing the research level of weak moving target's detection and tracking identification technology.
HYPERGOLIC REACTION MECHANISMS OF CATALYTICALLY PROMOTED FUELS WITH ROCKET GRADE HYDROGEN PEROXIDE
Abstract The coupling of the physical and chemical processes controlling the ignition delays (τ ign ) of hypergolic propellants complicates the direct analysis of the transient ignition processes. The transport properties of both the propellants and the ambient gas, and the heat of vaporization and reaction affect τ ign and must be considered experimentally. Furthermore, since hypergolic ignition occurs, by definition, on contact, the mechanics of initial contact and subsequent mixing can affect τ ign and must also be considered. Experimental results from a study of the hypergolic ignition of a catalytically promoted fuel with rocket grade hydrogen peroxide (RGHP) are presented. Statistical analysis of the experimental data was conducted to evaluate the relative effects of RGHP concentration, initial ambient pressure, and the ambient gas on τ ign . At RGHP concentrations of less than 92% in water, stable ignition was difficult to achieve. At sufficiently high Lewis number, an oscillatory ignition process is observed. A phenomenological model comprising mixing, RGHP decomposition, fuel heating and vaporization, and auto-ignition is presented and compared to the experimental results.