基于车载微波辐射计的地面观测试验方法

微波遥感具有全天时全天候的优点,并对云雾、雨雪和植被等有一定的穿透能力。地基微波辐射计以机动灵活的方式接收地表在微波波段的电磁辐射特性,被广泛用于土壤水分、冻融过程等微波遥感定量试验中。以车载多通道双极化微波辐射计(RPG-6CH-DP)为例,针对不同植被覆盖地表,在内蒙古多伦地区开展了为期3个月的野外观测试验,获得了L(1.4GHz)、C(6.925GHz)、X(10.65GHz)三个频率下的极化亮温观测数据。结果发现,L波段对植被的穿透能力最强,对土壤水分变化最敏感。微波辐射计观测地物的方位角、入射角均对观测亮温有直接影响。这为解译地物微波辐射传输过程及其相互作用机理、各种理论模型的发展和验证、地表参数反演算法的改进,以及相关地球观测卫星计划的载荷方案论证奠定了基础。

Ground Observation Experimental Method Based on a Vehicle-Mounted Microwave Radiometer

Microwave remote sensing can work at all-time and all-weather conditions, and can penetrate through cloud, fog, rain, snow and vegetation. The ground-based microwave radiometer is used to measure the electromagnetic radiation properties of the ground objects in a flexible way, and is widely used in microwave remote sensing quantitative experiments such as soil moisture and freeze-thaw process. In this paper, a vehicle-mounted multi-channel dual-polarization microwave radiometer (RPG-6CH-DP) is used as a tool in the field experiment for 3 months. The experiment is carried out to obtain the polarized brightness temperature data under three frequencies of L(1.4 GHz), C(6.925 GHz), X(10.65 GHz) of different vegetation types in Duolun of Inner Mongolia, China. The results illuminate that the L-band has a strong ability to penetrate vegetation, and is extremely sensitive to soil moisture variation. The observed microwave brightness temperature is affected by both azimuth and incidence angle directly. The dataset can be used for understanding the microwave radiative transfer process and its interaction mechanism with ground objects, development and verification of various theoretical models, improvement of surface parameter retrieval algorithm, and implementation of the related Earth observation mission.