低空热红外遥感诊断作物水分信息具有周期短、成本低等优点，而热红外遥感对作物水分的诊断主要是依据冠层温度或冠-气温差信息，但冠层温度对大气温度变化的响应具有一定的滞后效应，这种滞后效应又受到大气温度、太阳高度角和不同生育期作物表型信息等因素影响，使得热红外遥感诊断作物水分的精度较低。本项目以内蒙古河套灌区的玉米为对象，研究冠层温度变化的滞后效应对低空热红外遥感定量诊断作物水分的影响机理，阐明不同水分条件下冠层温度的滞后效应与大气温度之间的动态变化规律；建立太阳高度角和作物表型的耦合作用与冠层温度滞后效应之间的定量关系；揭示其对低空热红外遥感定量诊断作物水分的影响机理；建立基于冠层温度滞后效应的低空热红外遥感定量诊断作物水分数学模型。研究成果将有望提高低空遥感对作物水分的定量诊断精度，为田间水分管理和水资源高效利用提供科学依据。

The diagnosis of crop moisture information by low-altitude thermal infrared remote sensing has the advantages of short cycle and low cost, and it is mainly based on canopy temperature or the difference of air-canopy temperature. However, the response of canopy temperature to atmospheric temperature change has a certain hysteresis effect, which is affected by atmospheric temperature, solar height angle and crop phenotype information of different growth periods. The hysteresis effect results in the low accuracy of the thermal infrared remote sensing for diagnosing crop moisture. This project are: (1) to study the effect of the hysteresis effect of canopy temperature on the quantitative diagnosis of maize soil moisture by low-altitude thermal infrared remote sensing in the Hetao Irrigation District of Inner Mongolia Autonomous region; (2) to illuminate the dynamic variation rule between hysteresis effect of canopy temperature and atmospheric temperature under different water conditions; (3) to establish the quantitative relationship between the coupling effect of solar height angle with crop phenotype and the hysteresis effect of canopy temperature; (4) to reveal the mechanism of its influence on quantitative diagnosis of crop moisture by low altitude thermal infrared remote sensing; (5) to establish quantitative diagnosis model of crop moisture by low-altitude thermal infrared remote sensing based on canopy temperature hysteresis effect. The research results will be expected to improve the quantitative diagnostic accuracy of low-altitude remote sensing for crop moisture, and provide scientific basis for field water management and efficient utilization of water resources.