水稻叶片叶绿素含量遥感诊断是实现水稻精准施肥的核心要素。本研究通过分析寒地水稻关键生育期叶片高光谱反射率信息,同时结合PROSPECT模型叶绿素含量吸收系数,参考借鉴现有高光谱植被指数的构造方法和形式,利用相关性分析、连续投影...水稻叶片叶绿素含量遥感诊断是实现水稻精准施肥的核心要素。本研究通过分析寒地水稻关键生育期叶片高光谱反射率信息,同时结合PROSPECT模型叶绿素含量吸收系数,参考借鉴现有高光谱植被指数的构造方法和形式,利用相关性分析、连续投影法、遗传算法优化的粗糙集属性简约法进行高光谱特征选择,提出了仅含有695、507和465nm 3个高光谱特征波段的红边优化指数(ORVI)。与Index Data Base数据库中其他用于叶绿素含量反演植被指数,包括ND_(528,587)、SR_(440,690)、CARI、MCARI的反演结果进行了对比分析,结果表明:IDB数据库中的已有4种植被指数叶绿素含量反演模型的决定系数R^2分别为0.672、0.630、0.595和0.574;ORVI植被所建立的叶绿素含量反演模型的决定系数R^2为0.726,均方根误差RMSE为2.68,精度高于其他植被指数,说明了ORVI在实际的应用中,能够作为快速反演水稻叶绿素含量的高光谱植被指数。本研究能够为寒地水稻叶绿素含量高光谱遥感诊断及管理决策提供一定的客观数据支撑和模型参考。展开更多
In order to study the regularity of the vertical distribution of droplet deposition on rice plants during pesticide spraying operated by a low-flying multi-rotor plant protection unmanned aviation vehicle(UAV),water-s...In order to study the regularity of the vertical distribution of droplet deposition on rice plants during pesticide spraying operated by a low-flying multi-rotor plant protection unmanned aviation vehicle(UAV),water-sensitive spray cards were placed on the leaves at the top,in the middle,and at the bottom of rice plants to acquire data on droplet deposition.In this study,a suspension containing tricylazole and hexaconazole was used in the spraying.The water-sensitive spray cards were analyzed by the droplet deposition processing software iDAS to obtain the vertical distribution of the droplets sprayed by the plant protection UAV.The results showed that (1)significant variation was found in the coverage of the droplets in different vertical positions of the rice plants.Within the effective spray width,the best coverage of the droplets was found in the area just below the rotors,whereas the coverage of areas farther away from the rotors was poor.For the different vertical positions of the rice plants,the overall droplet coverage was 58.38%at the top,33.55%in the middle,and 11.34%at the bottom of the plants;(2)for all vertical positions,the average size of the droplets ranged between 110μm and 140μm,which was suitable for the control of plant diseases and insect pests.The highest droplet density was found at the top of the plants,and the distribution of the droplet density was similar in the middle and at the bottom of the rice plants;(3)the diffusion ratio at the top of the rice plants(0.84)was better than that in the middle(0.57)and at the bottom(0.37).The overall relative span could meet the requirements for the actual application.Except for the position in the middle of the plants,the relative span for the other positions of the plants was over 0.67,which is the standard value.This study demonstrated the distribution regularity of droplet deposition along with the vertical direction of rice plants during UAV-based spraying,which is of guiding significance for the use of UAVs in plant protection,the improvement of chemical utilization efficiency,and the reduction of pesticide and fertilizer pollution.展开更多
文摘水稻叶片叶绿素含量遥感诊断是实现水稻精准施肥的核心要素。本研究通过分析寒地水稻关键生育期叶片高光谱反射率信息,同时结合PROSPECT模型叶绿素含量吸收系数,参考借鉴现有高光谱植被指数的构造方法和形式,利用相关性分析、连续投影法、遗传算法优化的粗糙集属性简约法进行高光谱特征选择,提出了仅含有695、507和465nm 3个高光谱特征波段的红边优化指数(ORVI)。与Index Data Base数据库中其他用于叶绿素含量反演植被指数,包括ND_(528,587)、SR_(440,690)、CARI、MCARI的反演结果进行了对比分析,结果表明:IDB数据库中的已有4种植被指数叶绿素含量反演模型的决定系数R^2分别为0.672、0.630、0.595和0.574;ORVI植被所建立的叶绿素含量反演模型的决定系数R^2为0.726,均方根误差RMSE为2.68,精度高于其他植被指数,说明了ORVI在实际的应用中,能够作为快速反演水稻叶绿素含量的高光谱植被指数。本研究能够为寒地水稻叶绿素含量高光谱遥感诊断及管理决策提供一定的客观数据支撑和模型参考。
基金supported by the Key R&D Program of Liaoning Province(2020JH2/10200038)the National Key R&D Program of China(2016YFD0200700).
文摘In order to study the regularity of the vertical distribution of droplet deposition on rice plants during pesticide spraying operated by a low-flying multi-rotor plant protection unmanned aviation vehicle(UAV),water-sensitive spray cards were placed on the leaves at the top,in the middle,and at the bottom of rice plants to acquire data on droplet deposition.In this study,a suspension containing tricylazole and hexaconazole was used in the spraying.The water-sensitive spray cards were analyzed by the droplet deposition processing software iDAS to obtain the vertical distribution of the droplets sprayed by the plant protection UAV.The results showed that (1)significant variation was found in the coverage of the droplets in different vertical positions of the rice plants.Within the effective spray width,the best coverage of the droplets was found in the area just below the rotors,whereas the coverage of areas farther away from the rotors was poor.For the different vertical positions of the rice plants,the overall droplet coverage was 58.38%at the top,33.55%in the middle,and 11.34%at the bottom of the plants;(2)for all vertical positions,the average size of the droplets ranged between 110μm and 140μm,which was suitable for the control of plant diseases and insect pests.The highest droplet density was found at the top of the plants,and the distribution of the droplet density was similar in the middle and at the bottom of the rice plants;(3)the diffusion ratio at the top of the rice plants(0.84)was better than that in the middle(0.57)and at the bottom(0.37).The overall relative span could meet the requirements for the actual application.Except for the position in the middle of the plants,the relative span for the other positions of the plants was over 0.67,which is the standard value.This study demonstrated the distribution regularity of droplet deposition along with the vertical direction of rice plants during UAV-based spraying,which is of guiding significance for the use of UAVs in plant protection,the improvement of chemical utilization efficiency,and the reduction of pesticide and fertilizer pollution.
