Poyang Lake Water Chlorophyll Inversion And Spectral Shape Classification Based On GF-1 Image

Poyang Lake is China’s largest freshwater lake, compared with the traditional method of water quality detection, using remote sensing of water quality detection can save a lot of manpower, material and financial resources, and timeliness and wide area has a natural advantage.GF-1 satellite is the first satellite of China’s high satellite series. It realizes the high spatial and high temporal resolution of the perfect combination, and a short revisit period, in the monitoring of lake water quality change has important practical value.By analyzing the correlation coefficient between different models and measured data,this paper verifies the applicability of GF-1 satellite in Poyang Lake lake water chlorophyll concentration retrieval.Using the measured spectral data and ground measured water quality data build peak ratio model, the first order differential model,using the image band data and the ground measurement data build the single band model, the band ratio model and the three band model.The results show that the image ratio model B3/B1 has the largest correlation coefficient with the measured value,so the GF-1 satellite image is suitable for the inversion of chlorophyll in Poyang Lake waters.Using B3/B1 model to build statistical regression model, and Poyang Lake waters of the inversion and accuracy evaluation.Inversion of the waters of Poyang Lake by using the model, and using the measured data to evaluate the accuracy of the model. Inversion results show that the Poyang Lake water body chlorophyll concentration is good, belong Poor nutrition.The chlorophyll concentration in the water body is divided into five range values, and the spectral curve of any point in each concentration range is obtained.The percentage of pixel area in each concentration range as a constraint, the decision tree classification model is established by comparing the slope and range values of each model.Using the obtained decision tree classification model to classify the GF-1 image and compare it with the GF-1image obtained from the inversion model.The results show that the overall result is well.