A.S. Petrov1, A.G. Lukin2, V.P. Makarov3

1–3 JSC «NPO Lavochkina» (Khimki, Russia)

1 aspetr50@mail.ru, 2 timon01.tt@gmail.com, 3 vyacheslav.makarov51@gmail.com

Currently, global digital models of the Earth's topography are being created using space-based synthetic aperture radars operating in the bistatic tandem interferometric mode of imaging the Earth's surface, with a metre-level and higher accuracy in estimating its elevations above the geoid level. Two platforms equipped with synthetic aperture radars are used to implement the tandem imaging mode. Meanwhile, there are effective aircraft systems operating in the single-pass mode, and there are also reports of space-based systems of this type. In this regard, it is necessary to compare the characteristics of interferometric systems that use two and one platform in terms of their ability to provide accurate terrain modeling.

The paper analyzes the effect of variations in the parameters of a space-based interferometer operating in a single-pass mode for imaging the Earth's surface using a single antenna on the accuracy of creating a digital terrain model. It demonstrates that, as the positioning errors of the interferometer's objects increase proportionally to the value of the slant range, significant challenges arise, particularly for single-pass interferometers with a small perpendicular component of the base projection, due to the system's high sensitivity to variations in its parameters. The paper presents simulation results that support this conclusion.

A kinematic model of space interferometer base formation operating in the skewed detailed single-pass mode of the earth surface surveying, is developed. Numerical estimation examples of the objects positioning errors arising when using this interferometry method are given. It is shown that, all other things being equal, these errors exceed by more than an order of magnitude the errors arising in the tandem variant of the system implementation.

When designing space interferometer missions, the article's materials allow for a comparison of the accuracy of Earth's surface topography estimation achieved using the two considered options for capturing objects, which means that one of them can be chosen based on the specific goals.

The analysis conducted confirmed the possibility of implementing a space-based interferometer that operates in a single-pass mode of imaging the Earth's surface using a single antenna. However, this mode provides significantly lower (by at least an order of magnitude) geometric resolution of the terrain compared to the tandem version of the space-based interferometer. Additionally, there is an increased (we believe, unacceptably high) sensitivity of the interferometer's characteristics to variations in its parameters.

Petrov A.S., Lukin A.G., Makarov V.P. Implementation of a space-based interferometer that operates in a single-pass mode of imaging the Earth's surface using a single antenna. Achievements of modern radioelectronics. 2026. V. 80. № 5. P. 34–42. DOI: https://doi.org/10.18127/j20700784-202605-04 [in Russian]

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