Aston University develops lidar for crop monitoring

15 May 2024

Funding from UK Royal Society will support improved polarimetric lidar platform.

A project at the UK's Aston University has received financial support for its work on enhancing lidar for crop monitoring applications.

The award of a Royal Society Industry Fellowship grant worth £174,000 will be used to further develop a polarimetic lidar, funding work underway at the Aston Institute of Photonic Technologies (AIPT) in the lab of Sergey Sergeyev.

"My project's motivation is driven by the global and UK agenda on increased food production, requiring novel remote sensing approaches towards ICT - information and communication technology - in farming," commented Sergeyev.

"As declared at the World Summit on Food Security in 2017, the growth in the world's population requires increased and more efficient agricultural production."

Optics technologies are already at the forefront of these efforts, being applied in several different ways. A 2022 project at AIPT developed a sensor designed to analyze low levels of volatile organic compounds (VOCs) emitted by plants, as an indication of their health.

Lidar is a particularly attractive technology for remote sensing in agriculture and farming, potentially able to capture 3D images of plants and deliver information about their chemical composition and that of the environment. But there is room for improvement in the performance of lidar platforms used for this purpose, according to the Aston team.

The new research project, christened POLIDAR and scheduled to run through 2024 and 2025, will build on existing research at AIPT into polarimetric lidar and a patented instrumental platform developed at the institute.

The challenging task of agricultural efficiency

The principle behind polarimetric lidar combines polarimetry and non-coherent optical ranging, with the polarization signatures of the target plants adding valuable information to that available from direct imaging.

"Aston University's patented technique will be modified by using a laser emitting four time-delayed pulse trains with different states of polarization," said Sergeyev. "By comparing the input states of polarization and states of polarization of light reflected from plants, it will reveal information about the distance to plants and plants' leaf texture, such as water stress and pathogen infection."

POLIDAR also envisages an all-fiber design with a minimum number of bulk components, in order to reduce an instrument's footprint, cost and weight.

Salford-based digital and AI farming company Fotenix will act as project partner. Founded in 2018 as a University of Manchester spin-out, Fotenix already markets a crop monitoring platform named DELTA combining bespoke illumination sources, high-resolution image sensors and data analysis.

DELTA is "the first 3D multispectral imaging system tailored for plant tissue," according to Fotenix.

POLIDAR intends to make its enhanced polarimetric lidar platform affordable for farmers in the UK and worldwide, as a cost-effective solution to check if their plants are adequately watered and disease-free.

"Remote sensing is an essential tool to systematically address the challenging task of enhanced agricultural efficiency by providing real-time information about crop traits for yield estimation," said Sergey Sergeyev.