Testing the performance of a novel spectral reflectance sensor, built with light emitting diodes (LEDs), to monitor ecosystem metabolism, structure and function

Ryu, Youngryel; Baldocchi, Dennis; Verfaillie, Joseph; Ma, Siyan; Falk, Matthias; Ruiz-Mercado, Ilse; Hehn, Ted; Sonnentag, Oliver

doi:10.1016/j.agrformet.2010.08.009

Cited by 86 publications

(74 citation statements)

References 52 publications

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“…The interference filters have a bandpass of 10 nm at full width at half maximum (FWHM). Following Ryu et al (2010), prototype NDVI sensors used light emitting diodes (LEDs). LEDs had peak sensitivity at 630 and 800 nm with bandpass widths of 50 and 40 nm, respectively.…”

Section: Optical Measurementsmentioning

confidence: 99%

“…Furthermore, automated sensors typically require dual-view configurations with up-and down-facing detectors that must be well matched spectrally and radiometrically if they are to be comparable (Harris et al, 2014). To address the need for automated field measurements, new small and inexpensive optical sensors are emerging that can monitor dynamic vegetation indices such as PRI and NDVI (Garrity et al, 2010;Ryu et al, 2010;Eklundh et al, 2011;Harris et al, 2014). These automated sensors need to be tested and evaluated against field spectrometers, particularly if data are to be compared across sites and research deployments employing different instruments.…”

Section: Introductionmentioning

confidence: 99%

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Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

et al. 2015

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Abstract. The vegetation indices normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI) provide indicators of pigmentation and photosynthetic activity that can be used to model photosynthesis from remote sensing with the light-use-efficiency model. To help develop and validate this approach, reliable proximal NDVI and PRI sensors have been needed. We tested new NDVI and PRI sensors, "spectral reflectance sensors" (SRS sensors; recently developed by Decagon Devices, during spring activation of photosynthetic activity in evergreen and deciduous stands. We also evaluated two methods of sensor cross-calibration -one that considered sky conditions (cloud cover) at midday only, and another that also considered diurnal sun angle effects. Cross-calibration clearly affected sensor agreement with independent measurements, with the best method dependent upon the study aim and time frame (seasonal vs. diurnal). The seasonal patterns of NDVI and PRI differed for evergreen and deciduous species, demonstrating the complementary nature of these two indices. Over the spring season, PRI was most strongly influenced by changing chlorophyll : carotenoid pool sizes, while over the diurnal timescale, PRI was most affected by the xanthophyll cycle epoxidation state. This finding demonstrates that the SRS PRI sensors can resolve different processes affecting PRI over different timescales. The advent of small, inexpensive, automated PRI and NDVI sensors offers new ways to explore environmental and physiological constraints on photosynthesis, and may be particularly well suited for use at flux tower sites. Wider application of automated sensors could lead to improved integration of flux and remote sensing approaches for studying photosynthetic carbon uptake, and could help define the concept of contrasting vegetation optical types.

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Section: Optical Measurementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

et al. 2015

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“…To calculate this broadband NDVI four-component net radiometers (e.g., CNR-1/CNR-4, Kipp&Zonen, NL, Europe; LP NET14, Delta-OMH, IT, Europe; NR01/RA01, Hukseflux, NL, Europe) together with PAR sensors can be used. Several groups have adopted this approach and have developed their own sensors centered on these NDVI bands [19,20] while recently Ruy et al [21] showed the possibility to use light emitting diodes (LEDs) for monitoring vegetation reflectance in narrow spectral bands.…”

Section: Introduction: the Need For A Standardized Spectral Measuringmentioning

confidence: 99%

Ground-Based Optical Measurements at European Flux Sites: A Review of Methods, Instruments and Current Controversies

Balzarolo

Anderson

Nichol

et al. 2011

Sensors

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This paper reviews the currently available optical sensors, their limitations and opportunities for deployment at Eddy Covariance (EC) sites in Europe. This review is based on the results obtained from an online survey designed and disseminated by the Co-cooperation in Science and Technology (COST) Action ESO903-"Spectral Sampling Tools for Vegetation Biophysical Parameters and Flux Measurements in Europe" that provided a complete view on spectral sampling activities carried out within the different research teams in European countries. The results have highlighted that a wide variety of Sensors 2011, 11 7956 optical sensors are in use at flux sites across Europe, and responses further demonstrated that users were not always fully aware of the key issues underpinning repeatability and the reproducibility of their spectral measurements. The key findings of this survey point towards the need for greater awareness of the need for standardisation and development of a common protocol of optical sampling at the European EC sites.

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“…2). These sensors are typically manufactured using optical filters, light emitting diodes (LEDs) and photodiode detectors (Norton, 2010;Ryu et al, 2010). These sensors are characterized by relatively low cost (from a few hundred to a few thousand euros/dollars), ease of maintenance, weather-proof design, and low power consumption.…”

Section: Multispectral Vs Hyperspectral Sensorsmentioning

confidence: 99%

EUROSPEC: at the interface between remote-sensing and ecosystem CO<sub>2</sub> flux measurements in Europe

Porcar‐Castell

Arthur²,

Rossini

et al. 2015

Biogeosciences

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Abstract.Resolving the spatial and temporal dynamics of gross primary productivity (GPP) of terrestrial ecosystems across different scales remains a challenge. Remote sensing is regarded as the solution to upscale point observations conducted at the ecosystem level, using the eddy covariance (EC) technique, to the landscape and global levels. In addition to traditional vegetation indices, the photochemical reflectance index (PRI) and the emission of solarinduced chlorophyll fluorescence (SIF), now measurable from space, provide a new range of opportunities to monitor the global carbon cycle using remote sensing. However, the scale mismatch between EC observations and the much coarser satellite-derived data complicate the integration of the two sources of data. The solution is to establish a network of in situ spectral measurements that can act as a bridge between EC measurements and remote-sensing data. In situ spectral measurements have already been conducted for many years at EC sites, but using variable instrumentation, setups, and measurement standards. In Europe in particular, in situ spectral measurements remain highly heterogeneous. The goal of EUROSPEC Cost Action ES0930 was to promote the development of common measuring protocols and new instruments towards establishing best practices and standardization of these measurements. In this review we describe the background and main tradeoffs of in situ spectral measurements, review the main results of EUROSPEC Cost Action, and discuss the future challenges and opportunities Published by Copernicus Publications on behalf of the European Geosciences Union. 6104A. Porcar-Castell et al.: Linking remote-sensing and flux measurements of in situ spectral measurements for improved estimation of local and global estimates of GPP over terrestrial ecosystems.

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Testing the performance of a novel spectral reflectance sensor, built with light emitting diodes (LEDs), to monitor ecosystem metabolism, structure and function

Cited by 86 publications

References 52 publications

Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

Ground-Based Optical Measurements at European Flux Sites: A Review of Methods, Instruments and Current Controversies

EUROSPEC: at the interface between remote-sensing and ecosystem CO<sub>2</sub> flux measurements in Europe

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Testing the performance of a novel spectral reflectance sensor, built with light emitting diodes (LEDs), to monitor ecosystem metabolism, structure and function

Cited by 86 publications

References 52 publications

Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

Monitoring seasonal and diurnal changes in photosynthetic pigments with automated PRI and NDVI sensors

Ground-Based Optical Measurements at European Flux Sites: A Review of Methods, Instruments and Current Controversies

EUROSPEC: at the interface between remote-sensing and ecosystem CO&lt;sub&gt;2&lt;/sub&gt; flux measurements in Europe

Contact Info

Product

Resources

About

EUROSPEC: at the interface between remote-sensing and ecosystem CO<sub>2</sub> flux measurements in Europe