Echo view registration device and method for sub-aperture altimeter

Abstract

The invention provides an echo view registration method for a sub-aperture altimeter, which comprises the following steps of: multiplying a signal by a frequency scaling function to remove distance curved spatial variability; performing inverse fourier transform in a distance direction, multiplying by a conjugation of the inverse fourier transform of a certain function, namely a residual video phase correction function, and finishing residual video phase correction, namely 'deskew' processing; multiplying by an inverse frequency scaling function, namely eliminating a secondary phase error introduced by the frequency scaling function to finish scaling processing; multiplying the scaled signal by a linear phase function to perform distance migration correction so as to finish registration in a view distance direction; performing azimuth compression on an obtained sub-view of the view distance registration to obtain a compression sub-view corresponding to an aperture; and performing registration in an azimuth direction on all the obtained compression sub-views, and extracting each azimuth-registered equivalent sub-view unit for subsequent tracking estimation or imaging processing.

Description

technical field [0001] The invention relates to a sub-aperture altimeter, in particular to a sub-aperture altimeter echo visual registration device and method. Background technique [0002] The sub-aperture altimeter is a new generation of radar altimeter, which overcomes the limitations of traditional radar altimeter pulse limitations, and has many advantages such as high performance and miniaturization. The echo view registration and averaging method mainly realizes the sub-view compression and registration averaging of the sub-aperture altimeter, which is the key to the high-precision measurement of the sub-aperture altimeter. Traditional radar altimeter usually adopts the method of expanding the average time of pulse echo to improve the measurement accuracy when performing echo tracking. However, due to the defects of the traditional altimeter pulse-limited system, there is a pulse-footprint mismatch problem between the pulse-echo sequences used for estimation due to th...

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Problems solved by technology

[0004] The object of the present invention is, for overcoming such technology of DDA and does not consider the distance space variation of distance migration in wide beam time in practical application, has limited effective echo mean number, the sub-aperture altimeter echo of the present invention looks registration method The visual registration step provides a frequency scaling method to overcome the distance misregistration problem caused by the spatial variability of the distance. At the same time, after the visual registration is completed, the sub-aperture altimeter echo visual registration method of the present invention also performs azimuth The step of registration is to overcome the problem of azimuth misregistration caused by the deviation of each sub-aperture; in addition, in order to overcome the problem of low power utilization efficiency caused by the traditional non-focus compression method, the present invention also provides a focused compression method ; That is, the present invention provides a sub-aperture altimeter echo visual registration device and method

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