Plant Height Measurement System for Mobile Platforms

Technology #ua11-135

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Pedro Andrade sanchez
Assistant Specialist, Agricultural & Biosystems Engineering, Maricopa Agricultural Center
John Heun
Research Specialist, Maricopa Agricultural Center
Managed By
Tod Mccauley


A plant height instrument which incorporates RTK (real-time kinematics) quality GPS positioning to establish an exact, unchanging soil elevation reference base while in motion. The positioning data provides the compensation necessary to accurately measure plant height while driving over uneven terrain, overcoming the instability inherent in sonar sensors used with mobile platforms due to irregular terrain.


Using a sensor-based approach on a mobile platform, this method of measuring plant height allows users to observe changes in plant growth over time and provides high-quality, high-density data in or near real-time. This system provides a significant advantage over the current method of hand measurements, with comparable accuracy but with the speed of a machine which can acquire data over large areas quickly. A mobile system capable of measuring plant height in real-time could be used directly or with existing tractor electronic control systems to dispense fertilizers or plant growth regulator chemicals at different rates based on a plant’s health status. Such variable rate application of fertilizers or plant growth regulator chemicals has the potential to improve agricultural production efficiencies, increase economic returns to farmers, and reduce environmental risk.


•       Improved, non-contact, sensor-based system for measuring plant height in agricultural crops from a mobile platform.

•       Comprised of sonar range finder and real-time kinematics (RTK) GPS along with field computer.

•       System can provide high-quality, high-density plant height data over large areas in or near real-time.

•       RTK-GPS elevation positioning data provide compensation necessary to measure plant height while driving over uneven terrain.

•       Ability to obtain in real-time plant height and/or Height:Node ratio (H:N), an important biophysical measurement of healthy growth in cotton, could allow differential application of fertilizers and/or plant growth regulators based on plant’s health status. 



John Huen

Pedro Andrade-Sanchez



Tod McCauley

Licensing Manager, Tech Launch Arizona

Refer to technology UA11-135