Missile Plume Research Articles

Infrared radiation characteristics of dagger-type hypersonic missile

Hypersonic vehicles emit strong infrared radiation from their high-temperature exhaust plume and body, which is critical for infrared early warning, tracking, and guidance. In this work, a comprehensive analysis is conducted on the factors involved in air dissociation reaction within the shock layer of hypersonic missile heads, as well as the multi-component afterburning effect of the exhaust plume. A novel Reverse Monte Carlo Method (RMCM) is proposed for infrared radiation calculation, which utilizes two-dimensional Low-Discrepancy Sequences (LDS) to improve computational accuracy. The numerical calculations for a dagger-type missile show that afterburning reactions increase the temperature on the centerline of the outlet exhaust plume by about 1000 K. The total infrared radiation intensity of the missile is the highest in the 1–3 μm band, with the high-temperature wall of the nozzle being the primary source of solid radiation, and gas radiation primarily coming from H2O. The radiation intensity of the missile exhaust plume in the 3–5 μm band is the highest, with radiation sources primarily coming from CO2, CO, and HCl. Afterburning reactions of the exhaust plume increase the total infrared radiation intensity of the missile by about 0.7 times. These results can provide reference for the detection and guidance of hypersonic missiles.

Ultrahigh-Sensitivity and Fast-Speed Solar-Blind Ultraviolet Photodetector Based on a Broken-Gap van der Waals Heterodiode.

Broad-bandgap semiconductor-based solar-blind ultraviolet (SBUV) photodetectors have attracted considerable research interest because of their broad applications in missile plume tracking, flame detectors, environmental monitoring, and optical communications due to their solar-blind nature and high sensitivity with low background radiation. Owing to its high light absorption coefficient, abundance, and wide tunable bandgap of 2-2.6 eV, tin disulfide (SnS2) has emerged as one of the most promising compounds for application in UV-visible optoelectronic devices. However, SnS2 UV detectors have some undesirable properties such as slow response speed, high current noise level, and low specific detectivity. This study reports a metal mirror-enhanced Ta0.01W0.99Se2/SnS2 (TWS) van der Waals heterodiode-based SBUV photodetector with an ultrahigh photoresponsivity (R) of ∼1.85 × 104 AW-1 and a fast speed with rising time (τr) of 3.3 μs and decay time (τd) of 3.4 μs. Notably, the TWS heterodiode device exhibits a significantly low noise equivalent power of ∼1.02 × 10-18 W Hz-1/2 and a high specific detectivity of ∼3.65 × 1014 cm Hz1/2 W-1. This study provides an alternative method for designing fast-speed SBUV photodetectors with enormous potential in applications.

Gallium Nitride –Based Photodiode: A review

This paper shows Gallium Nitride material based photodiode as an overview to use it with different layer thickness in order to detect multi-spectral ranges and to obtain high performance, high responsivity, high speed and low cost optoelectronic devices. The earlier published works are summarized as well as the Gallium Nitride material grown on different substrates materials as silicon, or sapphire or quartz using different growth methods to fabricate photodiodes used in wide application field and get attractive attention to civil and military industries to detect missile plumes, flame sensors, engine control, solar UV monitoring, source calibration, UV astronomy, and secure space-to-space communications. GaN material based photodiodes are consider to be promising to open a new generation fields to their virtues to design high temperature, high frequency and high power optoelectronic devices.

Recent progress of SiC UV single photon counting avalanche photodiodes

4H-SiC single photon counting avalanche photodiodes (SPADs) are prior devices for weak ultraviolet (UV) signal detection with the advantages of small size, low leakage current, high avalanche multiplication gain, and high quantum efficiency, which benefit from the large bandgap energy, high carrier drift velocity and excellent physical stability of 4H-SiC semiconductor material. UV detectors are widely used in many key applications, such as missile plume detection, corona discharge, UV astronomy, and biological and chemical agent detection. In this paper, we will describe basic concepts and review recent results on device design, process development, and basic characterizations of 4H-SiC avalanche photodiodes. Several promising device structures and uniformity of avalanche multiplication are discussed, which are important for achieving high performance of 4H-SiC UV SPADs.

Research on the disturbance of ballistic missile to ionosphere by using 3D ray tracing method

This study uses the 3D ray tracing to analyse ionospheric disturbance generated by a ballistic missile plume (which was simulated in our previous work). Ray tracing results show that the 6 MHz radio waves are completely reflected by the ionosphere and cannot reach the ionospheric disturbance zone. The 8 MHz radio waves partially penetrate the ionospheric disturbance zone, producing a focusing effect. Most of the 10 MHz radio waves pass through the ionosphere and the disturbance zone. The focusing effect and focus height are reduced. In the height range 65̃400 km, the ray absorption loss of reflection is greater than the transmitted ray. When the ray is reflected multiple times in the cavity formed by the plume, ray absorption loss greatly increases.

Numerical Simulation of Ionospheric Disturbance Generated by Ballistic Missile

To provide theoretical guidance for the detection of ballistic missiles by skywave over-the-horizon radar, this paper first analyses the best way to detect ballistic missiles based on the rocket detection mechanism. Then using the diffusion model, chemical reaction model, and plasma diffusion model of neutral gas in the ionosphere, this paper studies the distribution of electrons and analyses the disturbance effect on the ionosphere caused by the release of ballistic missile exhaust plume in the ionosphere. Moreover, this paper considers the flight speed of the ballistic missile and the flow of the exhaust plume. Then the effects of different seasons, locations, and time zones on the release are compared. The results show that H2O can effectively dissipate background electrons to form spindle-shaped holes after release in the ionosphere. The height of the cavity radius corresponds to the peak of electron density of the background ionosphere, and the daytime dissipation is stronger than the nighttime dissipation, dissipation at low latitude is stronger than that at high latitude, and the seasonal difference is not obvious.

Influence of Oxygen Pressure on Growth of Si-Doped β-(AlxGa1 − x)2O3 Thin Films on c-Sapphire Substrates by Pulsed Laser Deposition

is a deep-UV transparent semiconducting oxide being interesting for solar-blind photo detectors e.g. for flame or missile plume detection. The bandgap of about 4.9 eV can be increased by alloying with . We have investigated β-(Al,Ga)2O3 thin films grown by pulsed laser deposition (PLD) on (00.1) with regard to the influence of the growth parameters such as growth temperature () and oxygen partial pressure (p(O2)) on the structural, optical and electrical properties of the samples. The thin films have (-201) orientation and the cation incorporation strongly depends on the deposition parameters. At a given , the incorporation of Al is favored for lower p(O2) due to higher dissociation energy of the Al-O bond compared to the Ga-O bond. At a given p(O2), the incorporation of Al is favored for higher due to desorption of gallium sub-oxides during growth.

Dim and Small Target Detection Based on Characteristic Spectrum

Dim and small target detection is one of the most challenging issues based on space-based detector. Original space-based detector only uses infrared bands, and the target information is limited in one-band image, so that detection error rate is high. In order to increase the target information, we suppose spectral imaging technology can be applied to the space-based detection system. Use bands of stronger radiation of targets than that of background as detection bands theoretically; the detection bands also can be called as the characteristic bands of targets. On these bases, the paper proposes methods of fuzzy fusion and fusion segmentation to achieve the target detection. Fusion is a combination of images from the characteristic bands, which can eliminate background, restrain noise, and enhance the target. Threshold segmentation and fuzzy algorithm assisted fusion algorithm to complete the final detection. In the simulation experiment, missile plume is considered as the detection target, atmosphere, cloud and jet plume is considered as the detection background, and the advantages of the characteristic spectrum detection and the proposed algorithm are verified from SNR, SCR, ROC curve, and time.

特征光谱图像中导弹尾焰的模糊识别

特征光谱图像中导弹尾焰的模糊识别

High-performance AlGaN metal–semiconductor–metal solar-blind ultraviolet photodetectors by localized surface plasmon enhancement

AlGaN-based solar-blind ultraviolet photodetectors have attractive potential applications in the fields of missile plume detection, biochemical sensing, solar astronomy, etc. In this work, significant deep ultraviolet detection enhancement is demonstrated on AlGaN-based metal–semiconductor–metal (MSM) solar-blind ultraviolet photodetectors by introducing the coupling of localized surface plasmon from Al nanoparticles with the high-Al-content AlGaN epilayer. The size-controlled Al nanoparticle arrays fabricated by nanosphere lithography can not only reduce the detectors' dark current but also bring about greatly enhanced responsivity. The peak responsivity of AlGaN-based MSM solar-blind ultraviolet photodetectors with Al nanoparticles can reach 2.34 A/W at 269 nm under 20 V bias, enhanced more than 25 times than that without Al nanoparticles. Our approach shows an efficient fabrication technique of high-performance and low-cost plasmonic enhanced AlGaN solar-blind MSM ultraviolet photodetectors.

Comparison of line-by-line and molecular band IR modeling of high altitude missile plume

This paper deals with the quantitative comparison of modeling IR radiation emitted from the plume of a tactical ballistic missile (TBM) in the boost phase with two different model approaches. IR spectra of the missile plume are calculated both with the high spectral resolution line-by-line radiation model FASCODE 3 (fast atmospheric signature code) using the databases HITEMP or HITRAN and the low spectral resolution IR radiation model NIRATAM ( NATO Infra Red Air TArget Model) using molecular band model technique. The influence of the atmosphere on the IR spectra as viewed from a space born sensor is taken into account. The results show, that using an elaborate line-by-line radiation model can improve the accuracy in computation of IR signature compared to the simpler but faster molecular band model technique used in NIRATAM.

Dual-SiC Photodiode Devices for Simultaneous Two-Band Detection

SiC is a highly useful material for optical sensing devices in the UV due to its large bandgap. It also exhibits a robust physical nature, making it suitable for harsh environment applications such as flame sensing. Here we report the first demonstration of SiC photodiode devices with multiple, independent detection components for sensing more than one radiation band simultaneously. The fabrication process and layout of the devices is described along with optical and electrical measurements of their performance. Individual sensing components exhibited peak responsivities greater than 60 mA/W at wavelengths of 290 and 320 nm. Optically tailored SiC devices, such as the ones described here, may further be applied to other applications such as missile plume detection, engine control, and communications in the solar-blind window. The application of particular interest for these devices was for flame temperature sensing. Testing the dual-SiC photodiode devices in front of a combustion flame showed a significant and linear dependence of the photodiode’s output ratio with temperature, demonstrating its feasibility. Successful determination of flame temperature would be a major improvement in the control and optimization of combustion processes. © 2005 The Electrochemical Society. All rights reserved.

EXPERIMENTAL STUDIES ON ROCKET EXHAUST PLUMES: SUPPORT FOR COMPUTED SIMULATION

Exhaust plumes of solid propellant missiles are heterogeneous flowfields containing gases and liquids or solid particles. Exhaust species mix with the atmosphere and may produce an afterburning flame. AP composite propellant combustion produces chloric acid which contributes to atmospheric water vapour condensation. A missile exhaust plume has harmful operational consequences. It may disturb the missile guidance system and increase engine and launch platform detectability. Specific computer codes are used in order to simulate operational missile exhaust plume effects. Because these codes have to be verified, experimental techniques have been developed in order to characterize static rocket exhaust plumes. Radiation structure, radiance and temperature are measured by video, infrared and UV camera. Radiative chemical species are identified by spectroradiometry. Flowfield is studied by laser doppler anemometry and laser tomography. Collected smoke particles are analysed by electronic microscopy and X-ray spectrometry. Meteorological thresholds for water vapour condensation are noted for various propellant compositions. Experimental setup, instruments and tested propellant are chosen in order to optimize comparisons between experimental results and numerical computations. Moreover, computer codes are modified to take experimental data into account. Experimental and computed results allow establishment of correlations between exhaust plume characteristics, motor parameters and propellant compositions.

Missile EMP Interaction: Dielectric and Plume-Connection Effects

Electromagnetic pulse (EMP) interaction with missiles composed largely of dielectric materials is considered. Effects of a dielectric missile body and the missile exhaust plume electrical connection on missile EMP response are evaluated.

A Faraday rotation measurement on the ionospheric perturbation produced by a burning rocket

The angle of rotation of linearly polarized waves radiated from missiles launched at Cape Kennedy was measured at a site in Yankeetown, Florida. The site was located so that the propagation path passed along the disturbed region in the missile plume. The electron content of the path was computed from the measured Faraday rotation and was compared with that computed from ionograms for the undisturbed ionosphere. This process was carried out for five Atlas flights. Results consistently indicated a deficiency in the electron density along the path in the F region, generally by about an order of magnitude.

Infrared Automatic Acquisition and Tracking System

A technique for accumulating airborne visible and infrared spectroradiometric data from missile plumes and re-entry objects establishes the requirements for a precision tracking front surface mirror. The processing of target radiation, reflected by the tracking mirror into an infrared tracker telescope, to derive target coordinate information, is described. The derivation of transformed target error signals to command the motion of the hydraulically driven tracking mirror is outlined. A description of the servo-electronics system, with selected circuitry, is given. The dynamic characteristics of the system, as determined from preliminary field tests, indicate that the system has a tracking rate capability of 10°/sec with an accuracy better than 60 seconds of arc. The detection sensitivity of the infrared tracker telescope is 1.6×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-10</sup> w/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> in the 2-to 6-α region, and is sufficient to provide 10-miile tracking ranges against a jet target in a sunlit cumulus cloud background. In a typical installation, aiming of the tracking mirror is provided by a 7×35, 10° field of view sighting telescope which is automatically slaved by the tracking mirror when acquisition and target tracking occurs, thereby providing continuous observation of the target. As an alternative to visual aiming, an automatic search program is generated by an accurate electro-mechanical programmer, which is described. Target acquisition, in an automatic mode of operation, is accomplished through the use of a simple logic circuit which provides electronic background discrimination by virtue of signal pulse width.