The Study of Inversion of Vegetation Biochemistry Parameters and Authentic Examination Based on High Spectral Remote Sensing
|School||Northeast Normal University|
|Course||Cartography and Geographic Information Systems|
|Keywords||High Spectral Remote Sensing Spectral Index Vegetation Radiative Transfer Model Inversion of Leaf Chlorophyll Content Inversion of Leaf Water Content The Authenticity Examination.|
The earth surface covers about 2/3 area of vegetation, which is an important component of land ecosystem. Many ecological process on land surface,for instance: the photosynthesis, the segregation of hydrocarbons circulation, the transpiration, the primary productive forces computation, wither ,the speed of falling of the decomposition and so on, especially the vegetation biochemistry parameter are closely connected with the vegetation. The vegetation biochemistry parameter includes: the pigment (mainly chlorophyll), the water content, the cellulose, the lignin, the starch, soluble nutritive elements ,sugar, protein (mainly nitrogen) as well as the carbon, the nitrogen, the hydrogen and so on . These parameter’s constitution and the content, directly or indirectly influences ecosystem process in the region or even the global criterion.The traditional methods of getting vegetation monitoring and estimation, the biochemistry parameter’s is based on the actual survey data in ground, in view of vegetation physiology and biochemistry parameters by direct or the indirect survey. In the measuring process, the traditional monitoring method is very easily to destroy the vegetation sample, and time-consuming ,hard sledding.Moreover,the great area’s monitoring is more difficult.The vegetation covering the land surface is the first surface layer and the most direct information through the remote sensing image, is also our object of study. The RS, relies on its superiority of macroscopic, fast, and the monitoring for great range of area,.At early time it uses in the recognition of vegetation covering type, the classification and the special charting and so on. Afterward, then it devotes to the special information extraction, and proposes many kinds of vegetation indices carring on the vegetation macroscopic monitoring and the biomass estimation. For example: the crops estimation, the estimation of the grass quantity and so on. Along with the quota remote sensing’s appearance, the vegetation of remote sensing turns toward a more quantitative direction to develop. Several dozens vegetation models’appearance play a significant part in the research of estimation of vegetation physiology, biochemistry parameter (chlorophyll content, leaf area index, vegetation degree of coverage and so on) ,which has provided the powerful method for them.Regarding the vegetation characteristic research,the traditional multi-wave band remote sensing data (for example SPOT, TM)have only provided the general red wave band (absorption characteristic) and the near-infrared wave band (reflection characteristic) and the infrared wave band (water absorption characteristic). With the restriction of wave band width of multi-spectrum remote sensing, the wave band numbers and the wave length’s position ,the vegetation type is not sensitive and is not ideal to vegetation’s examination. Along with the high spectral remote sensing’s development, relying on its many wave band numbers , the narrow wave band gap, it’s easy to obtain the goal space feature and at the same time also to be possible to obtain each pixel continual spectrum characteristics,which enables growing trend, the spectral response of examination vegetation more deeply and sensitively possible.Therefore, taking the remote sensing as a monitor method , particularly the high spectrum remote sensing, has not only provided the the wide range of data but also greatly reduced the research cost for the vegetation biochemistry parameter’s inversion.This article has studied the domestic and foreign inversion of vegetation biochemistry parameters that took the remote sensing as the main method, compare the former research technique and analyze, enhances strong points and avoids weaknesses, come to the inversion of vegetation chlorophyll content as well as the leaf blade water content using the spectral index together with the vegetation radiative transfer model , and then apply it to in the HJ star high spectrum data , finally carry on the fitting between biochemistry parameter’s simulation value and the actual value . Refer to the quality of the fitting degree,we can find the result of the authentic examination.