光与雷达遥感协作及其农业应用

用遥感影像提取农作物信息是精细农业的基础.传统的光学遥感局限于大气无云的优质影像,而微波遥感在提取农作物信息方面尚未得到充分的利用.寻找一种能够克服这些局限的农作物遥感信息提取的方法是有意义的.探讨了一种光和雷达遥感协作的方法,并应用于土壤和植被信息的提取,验证其应用潜力.用Karam等(1992)的微波散射模型,并作了相应修改:1)考虑粗糙地表面后向散射;2)光学遥感作为模型变量直接输入.将这种协作方法应用到两个数据集的处理,一个来自亚利桑那Maricopa农业中心,一个来自日本国家农业-环境科学协会的Tsukuba试验基地.这些数据包括一些实测的土壤和植被的数据以及陆地卫星Landsat和欧洲遥感卫星ERS遥感影像.结果初步表明雷达影像和光学影像在提取土壤和植被信息时可以有效地结合起来,在特定地方的农业管理中有着较好的应用前景.

Synergy of optical and radar remote sensing in agricultural applications

Ability to estimate crop information from remotely sensed imagery is fundamental in precision agriculture. Traditional approach using optical remote sensing is restrictive by cloud-free quality imagery while microwave radar has not been fully explored to infering crop conditions. In this study, an optical/radar synergy is developed to examine its potential for extracting soil and plant information. The synergy employs a microwave scattering model developed by Karam et al. (1992) but modified due to 1) taking into account underneath soil backscattering properties and 2) using optical remote sensing as direct input variables to the model. The synergistic method is applied to two data sets from Maricopa Agricultural Center, Maricopa, Arizona, and the experimental fields of the National Institute for Agro-Environmental Sciences, Tsukuba, Japan. The data sets include the images from Landsat and ERS satellites as well as some ground based soil and plant measurements. The preliminary results indicate that radar imagery can be effectively integrated with optical imagery for extracting both soil and plant information. There exist potentials to apply such synergy for site-specific agricultural management practices.