Building area extraction method and system based on SAR image

Abstract

The invention provides a building area extraction method and system based on an SAR image. The building area extraction method based on the SAR image includes: acquiring a first image on the basis ofthe SAR image; generating a local space index image and a variogram image on the basis of the first image; respectively screening sampling points on the basis of the local space index image, the variogram image and the first image to obtain corresponding sets; and processing sampling points in each set according to preset growth criteria to respectively construct to-be-selected building area images, superimposing all the to-be-selected building area images to obtain a final building area image. Through the method or the system provided by the invention, a building area can be quickly and accurately extracted from the Sentinel-1 SAR image, automatic extraction of construction land of a large region is realized, and a foundation is laid for global building area mapping.

Description

Technical field [0001] This application relates to the field of remote sensing, in particular to a method and system for extracting building areas based on SAR images. Background technique [0002] Studies have shown that 66% of the world’s population will live in urban areas by 2050. Although urban areas only account for a small part of the world's land, because they are gathering places for transportation and energy consumption, they affect the ecological environment to a large extent. Therefore, accurate and timely acquisition of building land information is of great significance to urban planning and post-earthquake disaster relief. [0003] Optical remote sensing satellites provide a valuable source of data for the extraction of construction land. However, compared with optical sensors, radar systems have the characteristics of all-weather observation and imaging all the time. Therefore, for areas covered by clouds and fog all year round, the radar system SAR data has a wide...

AI Technical Summary

Problems solved by technology

However, these methods only rely on the intensity information of the image. For example, for a low-resolution SAR image such as 75m, the settlement information can be accurately obtained, but for a medium-resolution wide SAR image (such as a Sentinel-1 SAR image with a resolution of 20m) , the building area has more obvious light and dark texture features, therefore, only using the intensity information cannot obtain a complete and accurate distribution of the building area

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