Method of extracting urban construction area threshold based on night light data

Abstract

The invention provides a method of extracting an urban construction area threshold based on night light data and belongs to the night light remote sensing data field. The invention comprises two phases of TM image data processing and night light DMSP data threshold selection and comprises the following steps of firstly, preprocessing research area TM image data, carrying out supervised classification and post-classification processing, and extracting urban lands; then superposing the night light data in a cut research area range and a drawn urban area polygon boundary so as to acquire one auxiliary straight line passing through a research area light data center area and the polygon boundary, and acquiring an auxiliary point adjacent to a light data threshold; and calculating an urban construction area represented by each auxiliary point and comparing to a statistical yearbook, taking a light data threshold corresponding to an area which is closest to the statistical yearbook as an optimum threshold of an urban construction area. In the invention, remote sensing image data is combined with statistical data, thresholds of urban construction area ranges with different sizes are accurately extracted and a change condition of an urban area is reflected.

Description

technical field [0001] The invention belongs to the field of night light remote sensing data, in particular to a method for extracting a threshold value of urban built-up areas based on night light data. Background technique [0002] With the rapid development of urbanization in China, exploring and understanding the spatial characteristics and changing characteristics of Chinese cities and optimizing the land use pattern in urban expansion are scientifically feasible for reducing the risk of urbanization process, improving the layout of urban development, and promoting urban economy. Sustainable development has very important strategic significance, and it can also provide data reference and decision-making basis for relevant government departments to formulate urban development strategies. [0003] The night light data is obtained by the Operational Linescan System (OLS) carried by the US Defense Meteorological Sate-llite program (DMSP) by acquiring the city lights at nigh...

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Problems solved by technology

The other three methods: because the extraction threshold of the empirical threshold method is determined according to previous experience and relevant background knowledge, the results of the extracted urban built-up areas are different due to the subjective influence of the researcher; when the mutation detection method extracts the threshold, It is necessary to determine the side length of the urban built-up area under each threshold. The required processing is complicated and the workload is heavy, which greatly increases the difficulty of extracting the urban built-up area; the statistical data comparison method uses computer language and uses binary The idea of ​​method is to continuously calculate the urban built-up area under each dynamic threshold and compare it with the statistical data released by relevant departments to extract the threshold. This requires researchers to have a certain programming foundation to achieve

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