Sub-band splicing method based on internal calibration data

Abstract

The invention discloses a sub-band splicing method based on internal calibration data. The sub-band splicing method comprises the following steps: step I: extracting in-band errors and time delay between channels; step II: processing amplitude errors and time delay extracted by an internal calibration signal in each sub-band; step III: shifting internal calibration compression positions of different sub-bands to a zero moment, and processing phase errors of each sub-band; step IV: reading radar echo data of sub-bands, and performing in-band error compensation of a single sub-band; step V: compensating in-band errors of each sub-band signal, and calculating time delay of each sub-band; step VI: performing upsampling on a frequency domain signal of each sub-band in the step V in a tail zero-filling mode; step VII: performing splicing process in a frequency domain; step VIII: obtaining a spliced time domain signal. The sub-band splicing method disclosed by the invention not only can compensate amplitude phase errors in the sub-bands, but also can compensate amplitude phase errors among the sub-bands as well as time delay among different sub-bands, and realizes coherent fusion processing of different sub-band signals.

Description

technical field [0001] The invention belongs to the field of signal processing and relates to a subband splicing method, in particular to a synthetic aperture radar subband splicing method based on internal calibration data. Background technique [0002] Synthetic Aperture Radar (SAR) satellites have developed rapidly in recent years. Since SAR satellites are not limited by factors such as weather, geography, and time, they can observe the earth all day long and have certain penetrating power, so they are widely used. It is used in military reconnaissance, topographic mapping, resource detection, ocean observation, ecological monitoring, natural disaster monitoring, rapid rescue, etc. [0003] High resolution is the eternal pursuit of synthetic aperture radar. The higher the resolution of SAR imaging, the better the understanding of the scattering characteristics of the target, the more sufficient the information of the imaging area is obtained, and the more accurate the pe...

AI Technical Summary

Problems solved by technology

However, in actual engineering, each sub-band receiver will have different amplitude and phase errors, and according to the frequency modulation characteristics of the chirp signal, there will be certain differences between sub-band signals received by different receivers with different center frequencies. time delay

The sub-band splicing is an extremely delicate process, and small errors will also have a great impact on the splicing effect, and will also affect the subsequent two-dimensional focus processing

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