Chenghai Yang

　　USDA-ARS Aerial Application Technology Research Unit, College Station, Texas, USA

　　Satellites and manned aircraft have been used as remote sensing platforms for decades. Recently, unmanned aircraft systems (UAS) have emerged as a low-cost and versatile platform for airborne remote sensing despite the safety concerns of commercial pilots operating in low-level airspace. This presentation will provide an overview of satellite- and manned aircraft-based platforms and imaging systems used for precision agriculture, including precision irrigation, over the last two decades. Various airborne multispectral, hyperspectral and thermal imaging systems we have developed or evaluated since the mid-1990s will be discussed. Recently-launched high resolution satellite sensors and UAS-based sensors will also be briefly discussed. Practical application examples will be provided to illustrate how these imaging systems and different image processing and analysis techniques have been used for assessing crop growth variability, detecting and mapping crop pests (diseases, insect damage and weeds), and monitoring crop water stress for precision agriculture. The three types of remote sensing platforms will be briefly compared in terms of image quality, ground coverage, data storage and processing, timeliness, and cost-effectiveness. Some of the challenges and opportunities on the use of remote sensing for precision agriculture and water management will be discussed.