Design And Research Of Airborne Sensor For Rice LAI

Agriculture is beginning to develop precisely in the management process.In the production process,crop management is an important part of precision agriculture.It is clear that the difference of crop groups is the focus of the management of crop production process,and the specific measures are put forward for each crop,In the case of less investment in production,get high production efficiency.Crop growth information is obtained from the precise management of crops used in the source of information,information on the growth of crops,the quality of the level of production and the number of decisions have a role.Crop canopy reflection of the spectrum,with a lot of information available on the crop canopy of the spectrum of information analysis,you can get the basic situation of crops,serving the crop of the precise management.Nondestructive monitoring technology based on canopy spectroscopy in the information collection,the sensor is the most critical device.UAV in space and time advantage,making the UAV in recent years in the application of agriculture in the rapid development.UAV is a reusable,man-made control of the power system,can carry different equipment to complete a variety of tasks unmanned flight device.In agriculture,unmanned aerial vehicles are used in remote sensing of farmland information,early warning of disasters and assessment of ground disaster size,spraying of fertilizers and pesticides,and so on.Based on these characteristics.UAVs are used in precision agriculture.Airborne detectors in the monitoring to achieve from the point measurement to the surface measurement changes,to overcome the traditional point measurement of the lack of efficiency has improved the quality.Based on these advantages,a UAV-equipped sensor can be designed to monitor rice LAI.In this paper,the LAI model is used to establish the empirical relationship model.Three kinds of traditional vegetation indices and a new vegetation index(RLAI)and LAI are established.The model of regression analysis and multiple regression is established.By comparing the model precision,It is concluded that the regression model of the new vegetation index(RLAI)and rice LAI is the best model.To study the principle of the growth of information without loss of monitoring crops,the study of the sensing principle of spectral information;developed a solar light only as a light source to optical signal processing system,electrical signal processing system and signal analysis system three Part of the composition of the rice LAI airborne sensor.Based on the analysis of the correlation between the hyperspectral information of rice canopy and the LAI of rice.the sensitive band was identified as 745nm,565nm.and the selected filter was used as the spectral element of the sensor.According to the reflection characteristics of rice canopy and the height of UAV measurement,the field angle of LAI airborne sensor and the structural parameters of sensor lens were determined.When the effect of sensitivity and resolution of rice LAI airborne sensor was ensured,The optical filter technology is adopted,which has a good effect on the improvement of signal-to-noise ratio.At the two characteristic bands of 745nm and 565 nm,they are detected as the incident light and the reflection on the surface of rice respectively.In order to ensure that the weak spectral information is recognized by the single chip computer,the amplifier circuit and the filter circuit are built.Using the embedded development technology,the model is written into the single chip computer,and the design of the whole LAI airborne sensor is completed.The static characteristics(linearity,sensitivity and retardation difference)of rice LAI airborne sensors were tested in the laboratory.The results of the nonlinear error of the 745nm and 565nm bands are 3.45%and 5.63%respectively.The results of the hysteresis error are 3.23%and 2.93%respectively,and the sensitivity of the sensor is good in linearity and sensitivity.The results were compared with those of LAI-2200C on the detection of rice by using rice LAI airborne sensor.The results showed that rice LAI airborne sensor could realize the real-time on-line detection of rice LAI.Rice LAI airborne sensor could meet the requirement of UAV in volume and weight,and could realize the rapid acquisition of rice growth information.