Summary:
UCLA researchers in the Department of Atmospheric and Oceanic Sciences have developed a novel and compact device for direct, real-time measurement of solar-induced chlorophyll fluorescence, enabling accurate monitoring of plant photosynthetic activity without complex calibration or spectral retrieval procedures.
Background:
Accurate monitoring of plant photosynthesis is essential for assessing carbon uptake, growth dynamics, and plant responses to heat and water stress. Solar-Induced Chlorophyll Fluorescence (SIF) refers to the emission of photons in the red to far-red spectral region from chlorophyll molecules following excitation by absorbed solar radiation and can serve as a direct proxy for photosynthetic activity. Although SIF has strong potential as a photosynthetic indicator, existing measurement techniques are largely confined to specialized research instruments. These systems are complex, bulky, expensive, require sophisticated spectral retrieval algorithms, and are subject to significant uncertainties arising from atmospheric effects. Thus, there remains an unmet need for a simplified, compact, and cost-effective approach for SIF measurement providing accurate, real-time sensing without reliance on complex numerical retrieval methods.
Innovation:
Dr. Jonas Kuhn and Prof. Jochen Stutz have developed a fundamentally new approach to SIF proximal remote sensing that overcomes the core limitations of existing systems. The proposed device achieves a dramatically reduced form factor and power consumption while simultaneously delivering substantially higher measurement accuracy. The device integrates high spectral resolution with ultra-high contrast performance, enabling direct and absolute quantification of SIF. Consequently, there is no external reliance on complex spectral retrieval algorithms. Notably, the system isolates the SIF signal, suppressing light reflected by a plant canopy, providing unprecedented signal-to-noise performance. Collectively, this technology presents the potential to revolutionize current measurement systems by enabling a low-power, compact, and highly precise platform that can transform plant phenotyping, ecosystem monitoring, and global carbon cycle assessment. This combination of performance, robustness, and efficiency positions the technology as a foundational enabler for next-generation precision agriculture, ecosystem monitoring, and climate research.
Potential Applications:
● Crop monitoring, selection, irrigation, and fertilization
● Crop breeding and high-throughput phenotyping
● Ecosystem and climate change assessment
● Carbon flux and productivity monitoring sites
● Satellite, drone, and airborne remote sensing platform validation
Advantages:
● Direct, real-time SIF quantification
● Compact and low-power system design
● High accuracy and low noise
● Eliminates complex spectral retrieval models
State of Development:
Working prototype in testing; manuscript pre-print published.
Related Publications:
Direct quantification of solar-induced chlorophyll fluorescence using compact solar-blind optical radiometers
Reference:
UCLA Case No. 2024-183
Lead Inventors:
Jonas Kuhn and Jochen Peter Stutz, Professor, Department of Atmospheric and Oceanic Sciences