A.S. Petrov1, A.E. Nazarov2, V.P. Makarov3

1–3 Lavochkin Association (Khimki, Moscow region, Russia)

During the operation of the space SAR, the problem arises of ensuring such a spatial orientation of the platform, in which a zero DC value will be provided in the direction of the side looking mode. The literature describes a method that allows solving this problem by rotating the platform at the angles of yaw and pitch. However, it is not possible to directly repeat the results obtained, since the authors did not provide details of the corresponding mathematical operations, as well as the algorithmic sequence of their execution. Therefore, it is necessary to obtain a complete summary of the calculated ratios that allow solving this problem and then verify the result obtained by numerical modeling.

In the introduction, the state of the issue is considered based on the materials of domestic and foreign publications and the purpose of the study is formulated.

The first section contains a description of the problem model being solved. It provides an exhaustive set of calculated ratios that allow us to determine such a dependence of the roll and pitch angles of the platform on the latitude parameter, at which a zero DC value is provided at any angle of sight of the earth's surface capture strip center by radar antenna pattern (AP), and, regardless of the viewing side – left or right.

In the second section, an expression is obtained for the targeting vector expressed in projections on the orts of the AFAR, which allows you to direct the maximum AP to a point with a zero DC value by phase control of the scanning process.

The third section is devoted to the model for constructing the projection of the antenna pattern (at the level of 3 dB) on the Earth's surface. The necessary calculation ratios are obtained.

The fourth section presents the results of numerical modeling with the construction of graphical dependencies of the DC on the latitude parameter, and also presents three– and two-dimensional images of the AP's projection to the Earth's surface at the level of 3 dB. In the three-dimensional projection, lines are drawn that limit the viewing lanes (left and right) along their extreme boundaries at viewing angles of ±25° and ±55°. The images are given in global and local (in the vicinity of the subsatellite point) scales.

The conclusions summarize the results obtained. The list of references contains 10 titles.

Petrov A.S., Nazarov A.E., Makarov V.P. Zero Doppler centroid steering during operation of space synthetic aperture radars. Achievements of modern radioelectronics. 2023. V. 77. № 1. P. 51–59. DOI: https://doi.org/10.18127/j20700784-202301-03 [in Russian]

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