G.V. Ershov¹, K.P. Likhoedenko², A.R. Murlaga³ 

1,3 JSC “Central Radio-Research Institute n. a. academician A.I. Berg” (Moscow, Russia)

2 Bauman Moscow State Technical University (Moscow, Russia)

A mathematical apparatus is set forth in this paper allowing to choose an appropriate ejection point for a parachuted jamming system to provide suppression of a given radar for a period of time t0 in rainy weather. 

In the suggested mathematical model the following assumptions were made. A parachute is an air-filled hemisphere of radius R deployed instantaneous at altitude y1 . While descending of a parachute is in progress no deformations take place, it is raining (rain intensity is γ) and there is no wind. Rain intensity is defined as part of canopy surface covered with raindrops, γ∈[0,1] . Masses of canopy and lines are neglected. Rain intensity is constant. All raindrops are the same and are presumed to be spheres of radius rк .

Canopy does not absorb and does not gather rainwater. Rainwater trickles down the canopy instantaneous.

An example of calculation is made showing that for a period of time t0 =100s when radius of a parachute is R= 0,5 m , slant distance between radar and jamming system is RП ≤3km and antenna beam width is αП =30° ejection point (0,2; 2) provides suppression of a given radar in heavy rain, ejection point (0,29; 2) provides suppression of a given radar in moderate rain and ejection point (0,5; 2) does not provide suppression of a given radar.

Numerical solution of derived equation of motion shows that without taking into consideration wind activity even a light rain influences deeply the motion of the parachuted jamming system. This must be taken into account when ejection point for a parachuted jamming system capable to provide suppression of a given radar for a period of time t0 is being chosen.

Oblique wind can change the rain thus changing motion pattern of a parachuted jamming system. Consideration of these and other weather conditions when ejection point for a parachuted jamming system is being chosen is left for further investigations.

Ershov G.V., Likhoedenko K.P., Murlaga A.R. Estimation of ejection place for parachuted jamming systems to pro- vide protection of high-speed objects in rainy weather. Radiotekhnika. 2021. V. 85. № 2. P. 74−82.  DOI: 10.18127/j00338486-202102-12 (In Russian).

1. Ershov G.V., Lihoedenko K.P., Korobkov Yu.Yu., Murlaga A.R. Principy proektirovaniya pro-stranstvenno-raspredelennyh sistem zashchity vysokoskorostnyh ob"ektov. Radiotekhnika. 2020. T. 84. № 7(13). S. 53–61 (In Russian).
2. Nenartovich N.E., Gorevich B.N. Sistema protivoraketnoj oborony SShA. Analiz i modelirovanie. M.: PAO «NPO «Almaz». 2018. 320 s. (In Russian).
3. Perunov Yu.M., Macukevich V.V., Vasil'ev A.A. Zarubezhnye radioelektronnye sredstva. Pod. red. Yu.M. Perunova. V 4-h kn. Kn. 2: Sistemy radioelektronnoj bor'by. M.: Radiotekhnika. 2010. 352 s. (In Russian).
4. Bystrov R.P., Dmitriev V.G., Potapov A.A., Sokolov A.V. Problemy radiolokacionnogo ob-naruzheniya malokontrastnyh ob"ektov. Voprosy perspektivnoj radiolokacii. Kollektivnaya mo-nografiya. Pod red. A.V. Sokolova. M.: Radiotekhnika. 2003. 512 s. (In Russian).
5. Yudin V.N., Osavchuk N.A. Opredelenie harakteristik podavleniya RLS navedeniya raket s po-moshch'yu aktivnoj shumovoj pomekhi. Radiopromyshlennost'. 2004. № l. S. 95–104 (In Russian).
6. Osavchuk N.A. Ocenka effektivnosti funkcionirovaniya RLS soprovozhdeniya v usloviyah dej-stviya prednamerennyh pomekh. Nauchnotekhnicheskaya konferenciya molodyh uchenyh, aspirantov i studentov, posvyashchennaya 100-letiyu so dnya rozhdeniya doktora tekhnicheskih nauk, professora, lau-reata Gosudarstvennoj premii SSSR, Zasluzhennogo deyatelya nauki i tekhniki RSFSR Mihaila  Samojlovicha Nejmana. Programma i sbornik tezisov dokladov konferencii. M.: MAI. 2005. S. 32–34 (In Russian).
7. Spravochnik po geofizike. M.: Nauka. 1965. 572 s. (In Russian).
8. Arzhanikov N.S., Sadekova G.S. Aerodinamika bol'shih skorostej. M.: Vysshaya shkola. 1965. 553 s. (In Russian).
9. Kamke E. Spravochnik po obyknovennym differencial'nym uravneniyam. M.: Nauka. 1976. 576 s. (In Russian).
10. Fligl' R., Buzinger Dzh. Vvedenie v fiziku atmosfery. M.: Mir. 1965. 468 s. (In Russian).