Crop height

  • Infra-red and ultrasound sensors
  • Detects canopy height
  • Regulated 5V or optional 6-15V raw power input
  • Serial data (3.3V logic level) or optional USB connection

The growth rate of crops is key in farming and agricultural research. We have developed a sensor that combines ultrasonic and infra-red sensors to measure the height of crop canopies and to deliver information about the density of foliage within the canopy.

Please contact for more information or to buy.


The unit combines ultrasonic and light-based measurement using downward facing sensors to measure the height above ground of the crop canopy beneath it. The sensor will return simple height readings as well as canopy density estimates from the sonar sensor which might be interpreted to estimate biomass. Designed to be mounted on a scaffold tube using a standard “key clamp” style bracket it is quick and easy to assemble, robust and waterproof (IP65). Once the sensor has been mounted, the height above ground is measured and fed to the sensor which then returns the height above ground of the crop canopy beneath it. The sensor is designed for long term and low power deployment in both experimental and production agricultural environments and can be easily integrated with a microcontroller or host computer system via the asynchronous serial connection. Example applications and source code can be found below.

The sensor is intended for measurement of crops such as maize and cereals. Detection of the early stages of cereal growth requires careful placement of the sensor directly over a row and close to the ground (~500mm worked well in testing). Maize is detected rather better due to the larger leaf area presented, but for best results mount the sensor close to the ground initially and raise it after the crop has established.

Electrical connections:

  1. 5V power supply capable of supplying peak currents up to 500mA, 38mA typical (can be left unconnected if powered via raw power line).
  2. Ground.
  3. RX to which commands are issued in order to configure and trigger the sensor.
  4. TX from which data is read.
  5. Power down line to be used in conjunction with raw power line (can be left unconnected).
  6. Raw power line for 6-16V power supply capable of supplying peak currents ofup to 500mA (can be left unconnected if powered via 5V power supply).


Weight: 280g including mounting bracket, 165g excluding bracket

Dimensions: 175 x 115 x 85mm including bracket, 115 x 93 x 75mm excluding bracket

Maximum mounting height: 3000mm


User guide (includes description of the serial protocol) can be found here: