Research on Ground Motion Metal Target Based on Rocket Projectile by Using Millimeter Wave Radiometer Technology

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1 Sensors & ransducers Vol. 17 Issue 6 June 014 pp Sensors & ransducers 014 by IFSA Publishin S. L. Research on Ground Motion Metal aret Based on Rocket Projectile by Usin Millimeter Wave Radiometer echnoloy Zhan Donyan Liu Pennan Dan Zhenzhen Department of Equipment Enineerin Shenyan Lion University Shenyan China el.: fax: liu070080@16.com Received: 4 April 014 /Accepted: 1 May 014 /Published: 0 June 014 Abstract: How to detect the round motion metal taret effectively is an important uarantee for precision strike in the process of Rocket Projectile fliht. Accordinly and in view of the millimeter-wave radiation characteristic of the round motion metal taret a mathematical model was established based on Rocket Projectile about millimeter-wave detection to the round motion metal taret. hrouh chanin various parameters in the process of Rocket Projectile fliht the detection model was studied by simulation. he parameters variation and effective rane of millimeter wave radiometer were obtained in the process of rotation and horizontal fliht. So a certain theoretical basis was formed for the precision strike to the round motion metal taret. Copyriht 014 IFSA Publishin S. L. Keywords: Millimeter-wave radiometer Rocket Projectile Metal aret Detection Parameters variation. 1. Introduction With the development of military technoloy much hiher requirements to detection system of the weapons are brouht forward for the new war mode meanwhile the detection capabilities the taret identification and the attack ability of precisionuided weapons are increasinly demanded to be improved so as to accurately identify and determinate the taret and then choose to attack it in the complex battlefield environment. Rocket projectile as a new type of ammunition used in smart modern weapons has attracted the attention to many countries because of its own advantaes such as easy to carryin intellient wireless data transmission and multi-mode trierin a number of countries like the United States and Russia put a ood deal of effort into this kind of ammunition [1]. It has important functions that a wide rane of search surveillance damae assessment and attack the taret by usin bidirectional data link to transport the battlefield information [-] which can drive modern warfare into a hiher mode stratey. It is crucial to detect the various performance parameters of rocket projectile accurately so as to be precision-uided in the modern science and technoloy society still it is an urent task on the overall desin of the rocket projectile [4]. In the near sensin techniques field the wavelenth of millimeter wave usually refers to electromanetic wave with a lenth between 1 and 10 millimeter and with frequency ranin from 0 to 00 GHz. Compared to infrared and laser millimeterwave detection has many advantaes which has not only hih precision and stron anti-interference but also the ability of all-weather workin and stron penetratin power what s more millimeter wave 1

2 Sensors & ransducers Vol. 17 Issue 6 June 014 pp also has a liht weiht small size ood performance low cost and so on. Passive millimeter wave system reconizes taret by relyin on anle measurement and taret emissivity differences which can overcome the taret flicker effect that will exist when active millimeter wave systems detect at short rane the taret can be identified and located accurately [5]. Accordin to the different radiation characteristics that the millimeter wave radiometer exhibit between different metal tarets once identified as the enemy metal taret it can be precisely struck and destroyed immediately.. Application Principle of Passive Millimeter-wave Radiometer.1. Characteristics of Millimeter-wave Radiometer Metal taret detection is mainly based on the fact that millimeter-wave has better discrimination ability of radiation characteristics of the metal and other substances to determine the presence of metal tarets. As lon as all of the matter in nature is in absolute zero above the entire electromanetic spectrum will spontaneously radiate outward the electromanetic enery (namely electromanetic waves). It is the electromanetic waves that the radiation enery of objects can be expressed as apparent temperature [6]. When the millimeter wave radiometer is applied to detect metal tarets the radiation temperature is detected to be zero no matter what environment it is because the millimeter-wave radiation rate of the metal taret is close to zero so the metal object can be determine. he emissivity of typical round object surface is showed in able 1 [7]. his paper calculates the temperature of the antenna accordin to their radiation characteristics. where ρ is the metal taret reflection coefficient. And temperature near the antenna radiation B( θ φ pi Δ f ) = ρ( θ) s + ε ( θ) + ε ( θ) + ρ ( θ) ε at at at at contrast ratio between round tarets and the metal is attainable Δ = B( θ φ pi Δf ) B = ρ( θ) s + ε ( θ) + ε at( θ) at + ρ ( θ) ε ( θ) ρ ρ ε ( θ) at at s at at () In order to analyze conveniently sky is assumed to be cloudless namely at =0 the above equation can be reduced to Δ = ρ ( θ ) + ε ( θ ) ρ () s he round metals (such as metal tanks) tarets can be identified after Δ is calculated [6 8-9].. Buildin Rockets Mathematical Models he rocket projectile is dexterous maneuverin and flies fast besides its interior is equipped with a sensor device. As a fliht carrier the antithetic formula millimeter wave radiometer is placed in the head of projectile bodies. It is based on radiation characteristic features of this kind of ammunition and radiometer millimeter wave to detect metal tarets on the round a mathematical model is shown in Fi. 1. s able 1. he emissivity of typical round object surface. Wavelenth errain mm 8 mm cm Metal surface Water surface Dry sand Pitch Meadow Concrete Principle of Millimeter-wave Radiometer Radiation When radiometer antenna scans the metal taret the antenna temperature is known: = ρ + ρ (1) B s at Fi. 1. Rocket Projectile mathematical model. Rocket projectile is always maintainin a certain altitude detection durin its fliht in accordance with the direct-fire and three point uidance low-level blow fliht stretch trajectory evolved to hedehoppin upper armor attack trajectory. When the rocket flew over the taret identified as an enemy metal taret proximity fuze detonates the warhead the warhead formattin jet hit toward the top oal at a constant inclination anle speed [10]. If the projectile is considered as a riid body the space motion will 14

3 Sensors & ransducers Vol. 17 Issue 6 June 014 pp be seen as the synthetic motion that center of mass move and the body rotates around the center of mass otherwise it is easily deformed by aerodynamic force effect. he quality of rocket projectile decreases due to constant fuel consumption so the movement of the projectile is more complex than riid body motion o help make thins easier considerin the movement of rocket projectile and taret as particle motion at one point namely curin parameters mathematical modelin and simulation is developed at the point that rocket projectile detect metal tarets durin terminal uidance under ideal conditions. Accordin to the millimeter wave theory metal tarets will be identified if Δ is detected when scannin the metal taret antenna temperature chane as followed: 0 Δ A = x1+ l y1+ wexp( )cos cos ( ) x1 y1 10 GHΔ 4 bs H β β dydx (8) Interation showed that the rane of interation depends on the rectanular taret. aret orientation is lon and short sides respectively parallel to the coordinate system x and y axes. arets scale is l in the x direction and w in the y direction taret can t be detected by the radiometer until it is positioned the desired taret position determined by the selection of x and y values which is referred to the antenna. 1 Δ A = ( ΔG ( θφ ) dω 4 4 (4) When the rendezvous case that radiometer detect the metal tarets is shown in Fi. (.1) H is the heiht of antenna away from the XY plane D is the projection of a metal taret A (x y) onto the x-axis metal tarets with temperature contrast Δ are in the XY plane. Wave beam millimeter wave radiometer scans taret in the XY plane at α anle the amount of chane of rotation anle is β. Metal taret differential unit is dxdy. Fi. 1 can be expressed as: l = H /cosβ x1 = H tan β y1 = l1 tan( α ) s1 = l1 /cos( α ) s = ( x x) + ( y y ) = + + = cos( + ) / ( ) = 1 1 s x y h θ ar s1 s s s1s bs f e / s1 (5) (6) 4. Detection and Simulation to Metal arets Accordin to the mathematical model of rocket projectile shown in Fi. 1 there is a flat metal taret B (x 1 y 1 ) on the round backround and simulatin an unknown metal motion taret A (x y) based on formula (8) set the radiometer parameter equal to Antenna Gain is G 0 =.041 db db beamwidth of antenna is θ db =7.5 normal the anle between the direction of radiometer and the normal of round is θ F =0 azimuth is α=0 offset is d=0 m the contrast of the taret and backround is 50 deree rocket projectile flies horizontally at a constant rotation speed of 40 rad/s samplin interval is ms he movin metal tarets sized at m were scanned by antenna beam of radiometer at a heiht from 15 m to 5 m the output waveform in case of any intersection is simulated accordin to equation (8). It is simulated by MALAB software and the output waveform is shown in Fi. after radiometer rotates a circle. here is some external interference in the space motion and the upper structure of metal taret has uneven surface such as turret etc. herefore the simulated waveform is irreular and not smooth as shown in Fi.. the followed formula can be obtained H θ = cos β cos( α) ar cos[ cos β cos ( α ) Hy tan( α) H tan ( α) + Hx tanβ + cos β cos β 1/ H cos β ] [ H( x + y + H ) ] (7) hen formula (7) is put into formula (4) and makin unit unified it is ettin as follows: Fi.. Millimeter wave detection to metal taret of output waveform. 15

4 Sensors & ransducers Vol. 17 Issue 6 June 014 pp Fi.. After interference detection output waveform. Fi. 4. he waveform of parameter at rotation speed 70 rad/s. he fiure above indicates the rocket projectile flies at a certain heiht and parallels to the horizontal X-axis as a rotatin fliht the top of the rocket is equipped with antithetic formula millimeter wave radiometer antenna beam first scans the round antenna receives radiation temperature on the round when the wave beam of radiometer scans the metal taret ede radiometer antenna receives a radiation temperature of the metal object the reason for the bell shaped pulse sinal shown in Fi. is a temperature difference between the round and the metal. After radiometer scans round the antenna receives the sinal from scannin sky. he waveform with a rotation anle from 90 to 70 is formed when there is no metal taret except the surface. his waveform is detection waveform used to depict radiometer rotates a circle because it is antithesis radiometer and its direction has a normal anle of 0 with the round the ratio of radiation reachin round to reachin sky is 1:. From the two fiures above the bell pulse outputted by the radiometer can be seen besides the pulse width the maximum and minimum slope the symmetry and heiht of the waveform can also be obtained moreover the threshold can be derived so as to calculate the eometric dimensionin of the taret and et the rendezvous information of taret and detection system. In the case of various parameters and undistorted waveforms the correspondin parameters rane is arrived at accordin to the variable parameter in actual fliht of rocket projectile: a). G 0 =.041 db θ db =7.5 θ F = m the contrast of the taret and backround is 50 deree samplin interval is ms he effective rane of rotation speed is from 0 rad/s to 70 rad/s. When the maximum of rotation speed is 70 rad/s the waveform is showed in Fi. 4. b). G 0 =.041 Db θ db =7.5 θ F = m the contrast of the taret and backround is 50 the rotation speed is 40 rad/s he effective rane of samplin interval is between ms and 0.75 ms. When the value of samplin interval is 0.75 ms it is showed in Fi. 5. Fi. 5. he waveform of parameter at interation time 0.75 ms. C). G 0 =.041 db θ db =7.5 θ F = m the contrast of the taret and backround is 50 the rotation speed is 40 rad/s samplin interval is ms. he effective rane of loiterin heiht is from 17 m to 8 m the taret will not be accurately detected when the loiterin heiht is more than the maximum which may make the model system unstable as shown in Fi. 6. Fi. 6. he waveform of parameter at flat fliht heiht 8 m. When the other parameters are chaned the results of simulation were not obvious or they are not 16

5 Sensors & ransducers Vol. 17 Issue 6 June 014 pp experimental. herefore after a lare number of simulations and verifications a conclusion can be drawn that the model is feasible when rocket projectile detects metal tarets throuh millimeter wave radiometer. 5. Conclusions Accordin to the theory of millimeter wave radiometer the rocket projectile as a modern loaded weapons and ammunition detectin tool has systematically achieved effective detection to the movin metal tarets on the round. By chanin the rocket projectile parameters in fliht and radiometer parameters limits waveforms based on each parameter and effective detection rane of parameters are obtained in the simulation results. Studies show that the establishment of this model has achieved the effective detection of movin tarets on the round and also provided sinificant practical applications to the identification of metal tarets. Acknowledements his work was supported in part by a rant from the Natural Science Foundation of Liaonin Province under (Grant No ) and the Industrial Research Prorams of Liaonin Province under (Grant No ). References [1]. Chuanwei Sun Lixin Qian Dexterous ammunition development summary Journal of Eneretic Materials Vol. 6 Issue 0 01 pp []. Xiaojin Zan Aipin Zhu he forein uidance of rocket development situation Journal of Wined Missiles Vol pp []. Chanxin Zhou Yutao Ju Rocket Projectile desin theory Beijin Institute of Press 005 pp [4]. Liu Can Wenwei Wan Research on Detectin the Rotate Speed of Lon Rane Rocket Projectile Based on Short wave-sinal Journal of Henyan Normal University Vol pp [5]. Xinuo Li Yuehua Li millimeter wave Nearsensin technical foundation Beijin Institute Of Press 009 pp. -4. [6]. Shi Xian Guowei Lou Modellin and calculatin of millimeter wave radiant temperature for armored taret Journal of Infrared Millimeter Waves Vol. 6 Issue pp [7]. Xin-Guo Li Yue-Hua Li millimeter wave Nearsensin technical foundation Beijin Institute of Press 009 pp [8]. Wan Min Xinuo Li Sinal simulation and taret reconition of MMW radiometer Journal of Infrared Millimeter Waves Vol. 17 Issue pp [9]. Yanmei Zhan Zhanzhon Cui Study on ank op Armour Detection by Usin Millimeter Wave Radiometer Journal of Detection & Control Vol. 6 Issue 004 pp [10]. Zaikan Qi Guidance ammunition technoloy Beijin Institute of Press 005 pp Copyriht International Frequency Sensor Association (IFSA) Publishin S. L. All rihts reserved. ( 17