Synthetic aperture radar interferometric ionized layer phase estimation and compensation method

Abstract

The invention relates to a synthetic aperture radar interferometric ionized layer phase estimation and compensation method, which is characterized by comprising the specific steps of: step 1, carryingout precision registration of primary and subsidiary images and resampling of the subsidiary image; step 2, optimizing a lookup table and resampling the subsidiary image again; step 3, carrying out bandpass filtering on the primary and subsidiary images, and generating full bandwidth and subband differential interferograms; step 4, performing ionized layer phase estimation; step 5, and conductingsurface deformation phase solution. The synthetic aperture radar interferometric ionized layer phase estimation and compensation method can obtain a more precise registration offset amount, significantly improves the coherence of the images, and is more continuous in interferograms. The synthetic aperture radar interferometric ionized layer phase estimation and compensation method constructs SLCimages of front and rear sub-bands, can identify the influence of ionized layer path delay on radar images by utilizing the multi-aperture radar interferometry, constructs two upper and lower sub-bandsignals with different center frequencies, estimates and eliminates phase errors caused by electron density change of the ionized layer through optimizing the ionized layer estimation processing step, and improves the interferometric precision.

Description

technical field [0001] The invention relates to a synthetic aperture radar interferometry (InSAR) ionospheric phase estimation and compensation method, and belongs to the technical field of synthetic aperture radar interferometry. It can effectively weaken the effect of ionospheric delay phase in the process of synthetic aperture radar interferometry processing under the condition that the coherence is satisfied, so that a more accurate surface deformation map can be obtained. Background technique [0002] When long-wavelength (such as L-band) spaceborne radar (SAR) system is imaging, the delayed phase caused by electromagnetic waves passing through the ionosphere will alias with the elevation phase, which will affect the radar imaging quality. The ionospheric delay phase can be divided into first-order phase and second-order phase. The first-order phase will produce group delay effect, which will lead to inaccurate target imaging position. The dispersion effect produced by ...

AI Technical Summary

Problems solved by technology

Through the study of high-precision GNSS positioning data, it is believed that Δφ Mag and Δφ Bend The sum of these two terms is of an order of magnitude larger than Δφ iono Much smaller, for InSAR dual-frequency phase data, it can generally only be used to estimate Δφ Nondisp and Δφ iono

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