Method for calculating vegetation indexes based on mixed vegetation indexes

Abstract

The invention relates to the field of vegetation remote sensing, in particular to a method for calculating a vegetation index based on a mixed vegetation index, which mainly comprises the following steps: S1, acquiring remote sensing image data of a research area, and preprocessing the acquired remote sensing image data in ENVI software; and S2, calculating the vegetation index of the ground object of each pixel point in the preprocessed remote sensing image in ENVI software by utilizing the mixed vegetation index, so as to obtain the vegetation index value of the ground object of each pixel point in the research area. The mixed vegetation index provided by the invention has high sensitivity to vegetation state change in a wider vegetation coverage range, and makes up for the defect of insensitivity of NDVI calculation in a high vegetation coverage area and RVI calculation in a low vegetation coverage area.

Description

technical field [0001] The invention relates to the field of vegetation remote sensing, in particular to a method for calculating a vegetation index based on a mixed vegetation index. Background technique [0002] The vegetation index mainly reflects the difference between the reflection of vegetation in the visible light and near-infrared bands and the soil background. Each vegetation index can be used to quantitatively explain the growth status of vegetation under certain conditions. In vegetation monitoring and remote sensing image processing, widely used vegetation indices are normalized difference vegetation index (NDVI) and ratio vegetation index (RVI). A major shortcoming of global vegetation assessments is the inherently non-linear relationship with biophysical characteristics such as vegetation cover (VF), leaf area index (LAI) and surface biomass. In general, NDVI asymptotically saturates in certain ranges of biomass and LAI and VF under the conditions of medium-d...

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Problems solved by technology

Moreover, when the vegetation index reaches a certain level, it becomes insensitive to changes in vegetation coverage; and RVI is widely used in estimation and monitoring of green biomass, especially in high-density vegetation coverage areas, but when the vegetation coverage is less than 50% When , the RVI is sensitive to the atmosphere and the performance of the biomass is weak

Therefore, in practical applications, NDVI and RVI cannot show strong sensitivity and stability under the three conditions of low-density coverage, medium-density coverage and high-density coverage.

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