The publication of this Handbook was supported by the Russian Federation

preparation stage includes the following tasks:
•  the collection and organization of  information on environmental conditions, existing maps 
and analytical data;
•  drafting a list of  soil varieties, as judged by the anticipated structure of  the soil cover;
•  the compilation of  a draft map of  soil cover based on remote sensing data, using high 
resolution images, or aerial photography including the use of  an unmanned aerial vehicle 
(UAV), etc.

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17
Chapter 2.Methods of studying, mapping and monitoring saline and alkaline soils 
Aerial photography from an unmanned aerial vehicle (UAV)
The sequence of  data collection on soil conditions of  a study site using the UAV includes the 
following operations and procedures:
•  capturing  aerial  images  using  the  UAV  (i.e.,  preparing  a  drone  with  a  camera  for  flight, 
making corrections for wind, sun, cloud, the influence of  windbreaks and man-made objects); 
timing the aerial imaging for the hours between 9.00 to 16.00;
•  adjusting the height of  the UAV flight to 80 to 100 m above test field(s), with the route
•  involving several circular assents and descends above the test field(s);
•  image data processing as required for the study purpose, re-processing the images obtained for 
further analyses or preparing an ortophotoplan for solving problems of  precision agriculture;
•  re-processing of  the images obtained involving adjustments of  brightness and contrast to 
uniform levels and selecting the optimal orientation of  the analysed image;
•  an ortophotoplan preparation involves merging the obtained aerial images.