2027-L16 Seeing Stress Before It Shows: From Low-Cost In-Situ Sensors for Agriculture Optimisation to Next-Generation Thermal Satellites

PROJECT HIGHLIGHTS

  • Detect vegetation stress from drought and heatwaves before visible symptoms appear using low-cost thermal and optical sensors. 
  • Improve understanding of plant temperature, transpiration and ecosystem responses to climate extremes. 
  • Link ground observations with LSTM and TRISHNA satellites to enhance vegetation monitoring across scales. 

Overview

Vegetation stress caused by drought, heatwaves, soil moisture deficits and disease is becoming an increasingly important environmental and societal challenge. Stress often manifests through changes in plant temperature before visible symptoms appear, making land surface temperature (LST) a powerful indicator of vegetation condition. Thermal observations provide direct information on plant energy balance and transpiration, while optical measurements offer complementary information on canopy structure, chlorophyll content and vegetation vigour. 

Current commercial monitoring solutions are often expensive, limiting their deployment across agricultural landscapes, ecological observatories and citizen science networks. Advances in low-cost thermal radiometry, multispectral imaging and embedded computing now create opportunities for cost-effective monitoring stations that can operate autonomously and support both local decision-making and satellite validation activities. 

Recent and forthcoming thermal infrared satellite missions, including the European Space Agency’s Land Surface Temperature Monitoring (LSTM) mission and the CNES/ISRO Thermal Infrared Imaging Satellite for High-resolution Natural Resource Assessment (TRISHNA), are expected to transform environmental monitoring by delivering unprecedented observations of land surface temperature at high spatial resolution. However, the successful exploitation of these observations requires reliable ground-based measurements capable of capturing vegetation dynamics at high temporal frequency and linking field-scale processes with satellite observations. 

This PhD project will develop an integrated low-cost in-situ vegetation monitoring station combining thermal radiometry and optical imaging to detect vegetation stress and provide a bridge between in-situ observations and satellite products. The project will investigate how thermal and optical measurements can be combined to identify early stress signals and how information from the ground station can be scaled and transferred to current and future satellite missions. 

This PhD will demonstrate an innovative and fully characterised thermal-optical monitoring tools to detect vegetation stress caused by heatwaves and drought. The project will deliver a low-cost monitoring station, new insights into vegetation temperature measurements, advanced stress-detection techniques, and a framework linking field observations with next-generation thermal satellite missions (LSTM and TRISHNA). By combining ground and satellite data, it will demonstrate an early warning system to support climate-resilient agriculture, improve drought monitoring, and enhance decision-making for farmers, researchers, and the Earth observation community. 

Figure 1:From in-situ vegetation monitoring to the satellite operational uptake. In-situ stations help develop a baseline for vegetation reactions to heat stress that can be used to calibrate and validate satellite image products. Source: own work. 

Schematic shows ground-based thermal and optical sensors monitoring plant canopy temperature and vegetation stress.

Case Projects

This project does not offer a CASE studentship

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How to apply

Each host has a slightly different application process.
Find out how to apply for this studentship.

All applications must include the CENTA application form.
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The methodology will initially focus on designing of an autonomous monitoring system for continuous vegetation stress detection. This will comprise of laboratory testing and calibration and the eventual field deployment of: 1) Thermal-infrared radiometers measuring upwelling and downwelling radiation, and 2) A low-cost multispectral optical camera optimised for vegetation monitoring. 

As this project investigates combining thermal and optical measurements for plant stress detection before visible deterioration occurs, you will: 

  • Develop algorithms for the time series of vegetation observations for automatic detection of vegetation stress.  
  • Establish methodologies linking ground-station observations with satellite-derived products, including aspects such as directionality effects and scale effects in thermal imagery. 
  • Develop a method for field validation of vegetation stress, interpretation and future exploitation of observations from thermal Earth observation missions, particularly TRISHNA and LSTM. 
  • Identify the mechanisms for transferability across spatial scales and investigate the potential for an operational early warning system for vegetation stress. 

DRs will be awarded CENTA Training Credits (CTCs) for participation in CENTA-provided and ‘free choice’ external training. One CTC can be earned per 3 hours training, and DRs must accrue 100 CTCs across the three and a half years of their PhD.  

The candidate will work with the science team lead for the future ESA LSTM mission, part of the Earth Observation Science group based at Space Park Leicester.  

The student will develop computational expertise in satellite data processing and coding/programming skills in Python whilst working on the High-Performance Computing Linux environment.  

The student will learn how to work in a professional experimental laboratory and receive instrumentation calibration/validation training and learn how to plan and execute fieldwork and experiments. 

Finally, the student will be trained in scientific communication (presentation to scientists and general public, report and scientific writing).  

Year 1 will establish project foundations through a review of state-of-the-art vegetation monitoring methods, evaluation of low-cost thermal-optical stations for vegetation stress detection, assess the benefits of combining thermal and multispectral observations, and develop methodologies supporting operational early warning systems. 

Year 2 will refine and finalise the approach by identifying optical measurements for surface emissivity estimation to improve in-situ land surface temperature retrievals and determine reliable time-series indicators of vegetation stress. 

Year 3 will assess the transferability of station-derived indicators to LSTM and TRISHNA satellite observations and quantify the impacts of observation geometry and directional effects on vegetation temperature and stress detection. 

Journal: 

Dash, S. K., Sembhi, H., & Sinha, R., 2026. Integrating UAV thermal imagery and in-situ data for high-resolution crop water stress–soil moisture dynamics over India’s agricultural hotspot. International Journal of Remote Sensing, 47(1), 1–26. https://doi.org/10.1080/01431161.2025.2593684  

Lausch, A., Bastian, O., Klotz, S., Leitão, P.J., Jung, A., Rocchini, D., Schaepman, M.E., Skidmore, A.K., Tischendorf, L. and Knapp, S., 2018. Understanding and assessing vegetation health by in situ species and remote‐sensing approaches. Methods in ecology and evolution, 9(8), pp.1799-1809. https://doi.org/10.1111/2041-210X.13025  

Göttsche, F.M., Olesen, F.S., Trigo, I.F., Bork-Unkelbach, A. and Martin, M.A., 2016. Long term validation of land surface temperature retrieved from MSG/SEVIRI with continuous in-situ measurements in Africa. Remote Sensing, 8(5), p.410. https://doi.org/10.3390/rs8050410 

 

Web page with an author: 

Spengler, D., Schmidt, R., Soszynska, A. Revolutionizing Agriculture through Thermal Satellite Insights https://thermal-rs.earsel.org/?page_id=632  

Siggs, Ch. Interviewed in the Thermal Lens, Those Space People podcast “Monitoring Plant Health from Space” https://thermal-rs.earsel.org/?page_id=669  

Langsdale, M., interviewed in the Thermal Lens, Those Space People podcast “The impact of directionality on Land Surface Temperature” https://thermal-rs.earsel.org/?page_id=692  

Web page with an institutional author: 

Special Interest Group on Thermal Remote Sensing, slides and recordings from a workshop in 2024, including various videos e.g., Introduction to retrieving surface temperature, future missions LSTM and TRISHNA, Evapotranspiration using TIR data https://thermal-rs.earsel.org/?page_id=1122  

Further details and How to Apply

Interested candidates are encouraged to contact Dr Harjinder Sembhi ([email protected]), Dr Darren Ghent ([email protected]) or Dr Agnieszka Soszynska ([email protected]) to discuss the project before applying.  

To apply to this project:  

  • You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.  
  • Please submit your application and complete the host institution application process via: CENTA PhD Studentships | Postgraduate research | University of Leicester.  Please scroll to the bottom of the page and click on the “Apply Now” button.  The “How to apply” tab at the bottom of the page gives instructions on how to submit your completed CENTA Studentship Application Form 2027,  your CV and your other supporting documents to your University of Leicester application. Please quote CENTA 2027-L16 when completing the application form.  

 Applications must be submitted by 23:59 GMT on Wednesday 6th January 2027.   

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