Title: An airborne multispectral imaging system based on two consumer-grade cameras for agricultural remote sensing Authors
Submitted to: Remote Sensing
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 29, 2014
Publication Date: June 6, 2014
Citation: Yang, C., Westbrook, J.K., Suh, C.P., Martin, D.E., Hoffmann, W.C., Lan, Y., Fritz, B.K., Goolsby, J. 2014. An airborne multispectral imaging system based on two consumer-grade cameras for agricultural remote sensing. Remote Sensing. 6:5257-5278. Interpretive Summary: Recent advances in imaging technologies have made consumer-grade digital cameras an attractive option for remote sensing due to their low cost, compact size, and user-friendliness. An airborne multispectral imaging system using two consumer-grade cameras was designed and evaluated for agricultural remote sensing data acquisition. One of the cameras was modified to take near infrared images that were coupled to a GPS receiver to document the location where the images were taken. Each pair of images are co-analyzed to measure vegetative indices, which are correlated to crop conditions. Airborne testing and analysis of the acquired images demonstrated that the imaging system will be a useful tool for farmers, researchers, and crop scouts for crop condition assessment, such as drought or disease stress, pest detection and many other agricultural applications.
Technical Abstract: This paper describes the design and evaluation of an airborne multispectral imaging system based on two identical consumer-grade cameras for agricultural remote sensing. The cameras are equipped with a full-frame complementary metal oxide semiconductor (CMOS) sensor with 5616 × 3744 pixels. One camera captures normal color images, while the other is modified to obtain near-infrared (NIR) images. The color camera is equipped with a GPS receiver to allow geotagged images. A remote control is used to trigger both cameras simultaneously. Images are stored in 14-bit RAW and 8-bit JPEG files in CompactFlash cards. Post processing procedures are used to align the color and NIR images to create four-band images. The imaging system was tested under various flight and land cover conditions and optimal camera settings were determined for airborne image acquisition. Images were captured at altitudes of 305-3050 m (1000-10000 ft) and pixel sizes of 0.1-1.0 m were achieved. Four practical application examples are presented to illustrate how the imaging system was used to estimate cotton canopy cover, detect cotton root rot, and map henbit and giant reed infestations. Preliminary analysis of example images showed that this system will be useful for crop condition assessment, pest detection and other agricultural applications.