A Study on Monitoring Frost of Main Crop in the Area of Ningxia by Using Remote Sensing
宁夏主要作物霜冻遥感监测研究

The frost occurred is lies on many factors, such as condition of weather, landform, soil texture, bacterial population and vegetation itself etc. To monitor the frost by using remote sensing, we have to solve many problems, for example, the precision of temperature retrieval and distribution of vegetation by using NOAA data. In addition, we have to consider to both the aerosol and humidity effect on the temperature retrieval. Due to above mentioned reasons, monitoring the frost by remote sensing is rather complicated and difficult. Based on the analysis of the characteristic and the law of the frost, using the data of NOAA and weather station during 1991 to 2000,as well as using the data of the frost damage, there are three methods were introduced to monitor the frost in Ningxia in this paper. The first is difference vegetation index (DVI) which monitoring the frost by means of the difference of vegetation index between fore\|frost and after\|frost. The second is temperature reference (TR) which monitoring the frost by compare to the difference between the temperature retrieval and frost index of crops. The third is the area of cold valley (ACV) which obtained ACV by integral the temperature below the frost index. We have examined the monitoring precision of those methods, the results show that each is available to monitor the different type of frost in Ningxia.