D.A. Yasentsev – Ph.D. (Eng.), Associate Professor, 

Department 410 «Radar, Radio Navigation and Avionics»,

Moscow Aviation Institute (National Research University)

E-mail: yasentsev@gmail.com

B.G. Tatarskiy – Dr.Sc. (Eng.), Professor, Director of a Scientific and Educational Center,

JSC «Concern «Vega» (Moscow)

E.V. Maystrenko – Ph.D. (Eng.), Head of the Research Department of the Scientific and Educational Center, JSC «Concern «Vega» (Moscow)

The solution of the problem of ground moving targets indication (GMTI) is based on the difference of spatial and temporal structures of signals reflected from a stationary background and moving objects. These differences make it possible to observe moving and stationary objects separately, which can be achieved using a variety of algorithms for processing received radio signals. 

When detecting small-size and low-speed ground moving targets (GMT), this mode is usually implemented together with the mode of synthesizing the artificial aperture of the antenna. With the most established approach to the synthesis of the aperture, the carrier makes a translational, most often rectilinear, movement during the irradiation time of the mapped portion of the underlying surface. This approach has a drawback associated with the impossibility of high-detail mapping of the surface ahead of the carrier's flight course. One way to overcome this disadvantage is to use the rotational movement of the rotor blades of helicopter-type carriers in the case of placement of transceiver modules in them.

The article deals with the features of the trajectory signal of moving targets in the case of their observation from the helicopter carrier during its forward motion. Expressions for the dependence of the current antenna – GMT distance on the variation of observation conditions, in particular, the relative position of the carrier and the GMT are analytically obtained. Next, expressions were obtained for the responses of a quasi-optimal system for processing a trajectory signal reflected from a moving target. 

As a result of the analysis of the obtained expressions, it was revealed that in the presence of a moving target on the mapped area of the underlying surface, its mark shifts along the azimuth axis relative to its true position, decreases in amplitude, and high-level lateral lobes appear. Such deformation is caused by the presence of uncompensated linear frequency modulation of the trajectory signal of the moving target, which is caused by the radial component of the velocity vector of the moving object.

The width of the response of the quasi-optimal trajectory signal processing system to the moving target signal is determined by the angular position of the observed target relative to the carrier velocity vector, as well as the time of accumulation of the trajectory signal in the process of synthesizing the artificial aperture of the antenna.

1. Aviatsionnye sistemy radiovideniya. Monografiya. Pod red. G.S. Kondratenkova. M.: Radiotekhnika. 2015. ISBN 978-5-93108-105-2. [in Russian]
2. Verba V.S., Tatarskiy B.G., Yasentsev D.A. i dr. Kompleksy s bespilotnymi letatel'nymi apparatami. V 2-kh kn. Kn. 1. Printsipy postroeniya i osobennosti primeneniya kompleksov s BLA. Monografiya. Pod red. V.S. Verby i B.G. Tatarskogo. M.: Radiotekhnika. 2016.  ISBN 978-5-93108-136-6. [in Russian]
3. Koshelev V.I., Kirdyashkin V.V., Sychev M.I., Yasentsev D.A. Aktual'nye voprosy radiolokatsii. Pod red. P.A. Bakuleva. Monografiya. M.: MAI. 2016. [in Russian]
4. Radiolokatsionnye sistemy aviatsionno-kosmicheskogo monitoringa zemnoy poverkhnosti i vozdushnogo prostranstva. Pod red. V.S. Verby,  B.G. Tatarskogo. Monografiya. M.: Radiotekhnika. 2014. [in Russian]
5. Yakubovich N.V. Boevye vertolety Rossii. Ot « Omegi» do «Alligatora». M.: Yauza: Eksmo. 2010. [in Russian]
6. Maystrenko E.V. Sintezirovanie apertury pri sovmestnom pryamolineynom i vrashchatel'nom peremeshchenii fazovogo tsentra real'noy antenny. Diss. … k.t.n. M.: MAI. 2013. [in Russian]
7. Tatarskiy B.G., Yasentsev D.A., Maystrenko E.V. Selektsiya dvizhushchikhsya nazemnykh tseley v rezhime sintezirovaniya apertury antenny pri kombinirovannoy postupatel'no-vrashchatel'noy traektorii dvizheniya fazovogo tsentra antenny. Informatsionno-izmeritel'nye i upravlyayushchie sistemy. 2016. № 1. S. 21–29. DOI 10.18127/j20700814-201601-01. [in Russian]
8. Tatarskiy B.G., Yasentsev D.A. Osobennosti sintezirovaniya apertury pri vrashchenii svyazannoy sovokupnosti fazovykh tsentrov real'nykh  antenn. Informatsionno-izmeritel'nye i upravlyayushchie sistemy. 2018. № 6. S. 14–24. DOI 10.18127/j20700814-201806-01. [in Russian]
9. Yasentsev D.A., Sergeev A.V. Issledovanie osobennostey traektornogo signala pri vrashchenii fazovogo tsentra real'noy antenny i nablyudenii nazemnykh dvizhushchikhsya tseley. Uspekhi sovremennoy radioelektroniki. 2018. № 10. S. 60–66. DOI 10.18127/j20700784-201810-08. [in Russian]