“…These technologies are attractive alternatives to LiDAR, due to their high performance, flexibility, and relatively low cost (Díaz-Varela et al, 2015). For remote sensing of plants, near-infrared (NIR) cameras have been used in many studies (Lee and Searcy, 1999; Sugiura et al, 2005; Berger et al, 2010; Cabrera-Bosquet et al, 2011; van Maarschalkerweerd et al, 2013; Colomina and Molina, 2014; Díaz-Varela et al, 2015; Torres-Sánchez et al, 2015), because plant leaves (or chlorophylls) strongly reflect NIR light (Knipling, 1970; Tucker, 1979; Fahlgren et al, 2015) and some indices based on NIR reflectance rate, such as normalized difference vegetation index (NDVI; Rouse et al, 1974), are useful for identifying plants and assessing their growing conditions via remote sensing. Some studies have indicated that NIR sensors have advantages over standard RGB sensors in plant monitoring (Nijland et al, 2014; Zhang et al, 2016).…”