If you are off to the European Geosciences Union Meeting in Vienna, Austria from 17–22 April 2016, then check out the following session and presentations:

Unmanned Aerial Systems: Platforms, Sensors and Applications in the Geosciences http://meetingorganizer.copernicus.org/EGU2016/pico/20488

Drone-acquired structure-from-motion photogrammetry for high-precision measurements of biomass in semi-arid rangelands
http://meetingorganizer.copernicus.org/EGU2016/EGU2016-7888.pdf

MISTRALE: Soil moisture mapping service based on a UAV-embedded GNSS-Reflectometry sensor
http://meetingorganizer.copernicus.org/EGU2016/EGU2016-5905.pdf

An illustration of front and side overlap from a graphic from DroneDeploy. We recommend HIGHER fore- and sidelap than the image above (see previous paragraphs).