Method for choosing time for ISAR optimal imaging

An optimal imaging time and azimuth technology, applied in the direction of reflection/re-radiation of radio waves, use of re-radiation, measurement devices, etc., can solve problems such as poor accuracy and real-time performance, and achieve good estimation accuracy and robustness. Robust, low-computation effect

Inactive Publication Date: 2014-01-01
NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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Problems solved by technology

Existing algorithms require manual intervention to work properly and are not accurate and real-time

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  • Method for choosing time for ISAR optimal imaging
  • Method for choosing time for ISAR optimal imaging
  • Method for choosing time for ISAR optimal imaging

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Embodiment Construction

[0039] Below in conjunction with accompanying drawing, a kind of ISAR optimum imaging time selection method that the present invention proposes is described in detail:

[0040] The target motion of a ship at sea is usually complex, and the motions that contribute greatly to imaging are: relative cruising, pitching, rolling, and yaw motion. In the case of low sea conditions, the Doppler frequency required for imaging is mainly obtained by the relative cruise between the radar carrier aircraft and the ship, and the equivalent rotation vector is biased to the vertical rotation axis, and the top view of the ship can generally be obtained; in high sea conditions In this case, the swing of the target itself is relatively strong, among which the roll is the strongest, followed by the pitch, and the yaw is weak, while the flight rotation vector of the carrier aircraft relative to the ship is relatively the weakest, and the equivalent rotation vector is biased towards the horizontal rot...

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Abstract

The invention provides a method for choosing time for ISAR optimal imaging. According to the method, length apriori information in the target distance direction is used, the pitching rule of a ship target is combined, and the intrinsic pitching period of a ship is estimated; the intrinsic pitching period is used for insulating the interference of a micro-Doppler effect on a Doppler broadening curve, and a reliable basis is provided for selecting the cut-off frequency of a low-pass filter of the Doppler broadening curve; a variance concept in a probability statistics theory is used, and the average Doppler broadening of all primary images of the target is estimated. The method for choosing the time for ISAR optimal imaging obtains good estimation accuracy and robustness, the computation amount is low, and the method is suitable for real-time application.

Description

technical field [0001] The invention belongs to the technical field of radar imaging, in particular to an ISAR optimal imaging time selection method. Background technique [0002] Inverse Synthetic Aperture Radar (ISAR) can be used to image ships at sea with high resolution. As we all know, the range resolution of ISAR depends on the bandwidth of the transmitted signal, while the resolution in azimuth depends on the equivalent rotation of the target relative to the radar. For a ship target at sea, the equivalent rotation in low sea conditions mainly depends on the relative cruise between the target and the radar; while in high sea conditions, the roll, pitch and yaw of the ship are caused by sea surges. The three-dimensional motion of becomes the main source of equivalent rotation, and the above three-dimensional motion generally presents periodic characteristics in their respective dimensions. The equivalent rotation vector of the three-dimensional motion synthesis leads ...

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01S13/90
CPCG01S7/415G01S13/904G01S13/9064
Inventor 朱岱寅俞翔
Owner NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
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