Zhelezova S.V., Ananiev A.A., Vyunov M.V., Berezovsky E.V.
WINTER WHEAT CROP SURVEY WITH UNMANNED AERIAL VEHICLE AND OPTICAL SENSOR GREENSEEKER® RT200 ^{[№ 6 ' 2016]}
Using of unmanned aerial for crop survey by NDVI is expedient. Passive sensors (cameras) are using for survey, so the results depend on lighting conditions at the photographing time. For the calibration and verification of remote data from passive sensor it is necessary to conduct ground surveys by sensor with active radiation source. The using of Unmanned Aerial Vehicle (UAV) SenseFly AG eBee (camera Canon S110 NIR) for monitoring of winter wheat was shown. Normalized Difference Vegetation Index (NDVI) was measured by remote passive NIR camera and at the same time on the field by optical sensor GreenSeeker® RT200 with active light source. Using of active light source optical sensor is a standard method for NDVI measurement and it should be used for passive sensor calibration and correction of the results. Linear relationship is used for correction passive sensor measurement of NDVI value at the early crop stages (from seadling to tillering). Logarithmic equation is used for correction at the later crop stages. Crops UAV survey gives precise and repeatable measurements of NDVI distribution in the fields at different stages of crops development. It is demonstrated on the series of synchronic near the ground and remote surveys during the active growing season.