Study On Monitoring Method Of Winter Wheat Sowing Date Based On Remote Sensing Data Of Crop Crop Time Series

Wheat has a prominent position in China’s economic development and contributes positively to China’s food security.For the agricultural sector,high-quality and high-yield and real-time monitoring of wheat is particularly important.Generally,the optimal sowing period of wheat will be released according to different annual temperature and precipitation conditions.The guiding opinion,therefore,there is a strong demand for remote sensing monitoring of sowing date in the early stage of winter wheat growth.For the current use of remote sensing data of the whole growth period,based on the vegetation phenological remote sensing monitoring method,fitting the sowing time lag,using only the winter wheat pre-growth spectrum monitoring,the monitoring accuracy caused by the weak vegetation spectral signal is not high,this paper is based on the winter wheat crop Maturity-time-variation of winter wheat sowing-pre-growth growth,study the use of winter wheat crop crop timing information to construct a sowing date remote sensing monitoring model,monitor time and improve precision in advance,and provide new ideas and theoretical basis for sowing date monitoring.Firstly,the ESTARFM high-temporal resolution data fusion algorithm is used to image the MODIS and Landsat image data,and the multi-source remote sensing data is used to generate the high-temporal resolution data set.Secondly,based on the time series data and the vegetation candidate,the wheat planting area is extracted according to the phenology.Curves were used to study the characteristics and regularity of time series curve changes in early,timely and late harvesting of winter crops,early,timely and late sowing in winter wheat.Finally,based on hyperspectral remote sensing data processing method and time series data analysis technology,based on winter wheat crops The characteristics of the remote sensing data of the mature-lower crops were studied.The characteristics of the remote sensing vegetation index of winter wheat in different sowing dates were selected,and the relationship between the seeding and the sowing date was analyzed.The winter wheat sowing date monitoring model based on the remote sensing data of the crops was constructed.The main research results are as follows:(1)Based on the ESTARFM high spatial-temporal resolution data fusion algorithm,the Landsat8-OLI and MODIS data were fused to generate an 8-day time series image of the study area with both MODIS temporal resolution and Landsat spatial resolution.(2)During the late growth period to the maturity of winter wheat cultivars,and the time series data from the sowing to the pre-growth stage,the early winter wheat vegetation index was the highest,the winter wheat vegetation index was lower,and the last crop was harvested to the wheat growth stage.The time series data can reflect the sowing date of winter wheat.(3)Based on the time series data and vegetation index,the winter wheat sowing date model was used as the independent variable.The winter wheat sowing date was used as the dependent variable for regression analysis and testing.The winter wheat sowing date estimated by the model and the winter wheat sowing time of the ground measured data were used.The comparative analysis shows that the sowing date monitoring model based on the remote sensing data of the cropping time series can show better prediction ability.