The fluorescence box (FloX) is an unique instrument, enabling the continous observation of chlorophyll fluorescence. It measures spectral data of extremely high resolution, yet is built to withstand the hazards of a permanent outdoor installation.

Flyer Manual


The fluorescence box (FloX) is an unique instrument, enabling the continous observation of chlorophyll fluorescence. It measures spectral data of extremely high resolution, yet is built to withstand the hazards of a permanent outdoor installation.

It represents the evolution of prototypes such as the Multiplexer Radiometer Irradiometer (MRI), SFLUOR box and SIF-System developed from a collaboration between Jülich Research Center and the Remote Sensing of Environmental Dynamics Laboratory of the University Milano Bicocca. The basic routines of the FloX are based on SPECY (Forschungszentrum Jülich, IBG-2: Plant Sciences).

The FloX is specifically designed to passively measure chlorophyll fluorescence under natural light conditions. Therefore the design is optimized to achieve maximum efficiency in terms of: Signal to Noise Ratio, Spectral Resolution and quick acquisition time. The core of the system is the QEPro spectrometer from Ocean Optics covering the Red/Near Infrared region (650 – 800 nm). This is the spectral range where chlorophyll fluorescence is emitted and where the two atmospheric oxygen absorption bands (O2B and O2A, at 689 nm and 760 nm respectively) are used to measure it. Upward and downward channels of the FloX allow to measure the solar irradiance and the reflected radiance from the canopy. In order to keep a stable level of dark current the spectrometers are embedded in a temperature controlled housing. The signal-to-noise is maximized thanks to accurate automatic optimization of the signal of both channels and a high performance optical light throughput.


OPTIC Spec 1

Wavelength range

650—800 nm

Spectral Sampling Interval (SSI)

0.17 nm

Spectral resolution (FWHM)

0.3 nm

Signal to Noise Ratio (SNR)


Field Of View (FOV)

Dual FOV. Upwelling radiance 25°. Downwelling radiance 180°

OPTIC Spec 2

Wavelength range

~ 400–950 mn

Spectral Sampling Interval (SSI)

~ 0.65 nm

Spectral resolution (FWHM)

~ 1.5 nm

Field Of View (FOV)

Dual FOV. Upwelling radiance 25°. Downwelling radiance 180°


Signal Optimization

Automatic adaption to varying light conditions

Dark current

Accurate dark current determination at each measurement cycle

Manual acquisition

Interface software for manual measurement and calibration

Automatic acquisition

Fully autonomous measurement mode for unattended data acquisition

Quick measurements

20 seconds under bright sunshine 60 seconds in overcast condition


Reference system stability check and uncertainty estimates

Simultaneous metadata

Spectrometer temperature, Outside temperature, GPS position, GPS time

Data Display

Live assessment of the systems status

Data storage

SD card up to 32 GB (12 months of measurements)


Robust and Waterproof housing based on the 1510 Pelicase


Small form factor (50 × 30 × 20 cm)

Power supply

12 Volt. From battery or solar panels

Power consumption

Average consumption of 60 Watt. (20/100 Watt, cooling on/off)

Energy saver

Day/night switch for energy saving


RS232 via cable and wireless


Dust Protection

Additional dust protection for Cosine Receptors

Fiber optics

Flexible length of fiber optics according to user needs

Power supply

Solar panel and battery


Addon for LAN/WLAN/Mobile Network Remote access




How do I process the FloX data?

To calculate fluorescence, radiance, reflectance and a variety of vegetation indices, an open source R package was made in collaboration with Max Planck Institute and University of Milano Bicocca and is available in github. The package is wrapped with a graphical user interface to allow processing of years of data with a few clicks.

How can the FloX be integrated for remote access and live datastream

The basic FloX is equipped with an USB interface to stream data directly to a connected computer.  SDI-12 is also available to stream real time up to 9 variables (VIs, SIF and vital data). The Optional embedded PC if coonected to internet allows the daily data transfer of the full daily data.

Can the FloX be used on a drone?

Don´t even think of it. The FloX is a rugged and pretty heavy instrument and absolutely not designed for airborne use. But you may get in touch with us for a glimpse on some secret projects.

Can the FloX be used in a mobile way?

Yes. Checkout the FloX2Go option but be aware that fluorescence measurements require very stable measurement setups and work best in a fixed position.

What is the delivery time of the instrument?

Delivery time ranges from one to a maximum of three month

Can JB provide assistance for instrument installation?

Yes. Just get in touch with us to request our installation service.


Deriving photosystem-level red chlorophyll fluorescence emission by combining leaf chlorophyll content and canopy far-red solar-induced fluorescence: Possibilities and challenges. Remote Sensing of Environment 2024.

Linsheng Wu, Yongguang Zhang, Zhaoying Zhang, Xiaokang Zhang, Yunfei Wu, Jing M. Chen


Towards a standardized, ground-based network of hyperspectral measurements: Combining time series from autonomous field spectrometers with Sentinel-2. Remote Sensing of Environment. 2024

Paul Naethe, Andrea De Sanctis, Andreas Burkart, Petya K.E. Campbell, Roberto Colombo, Biagio Di Mauro, Alexander Damm, Tarek El-Madany, Francesco Fava, John A. Gamon, Karl F. Huemmrich, Mirco Migliavacca, Eugenie Paul-Limoges, Uwe Rascher, Micol Rossini, Dirk Schüttemeyer, Giulia Tagliabue, Yongguang Zhang, Tommaso Julitta


The relationship between wheat yield and sun-induced chlorophyll fluorescence from continuous measurements over the growing season. Remote Sensing of Environment 2023.

Jie Zhu, Yuming Yin, Jingshan Lu, Timothy A. Warner, Xinwen Xu, Mingyu Lyu, Xue Wang, Caili Guo, Tao Cheng, Yan Zhu, Weixing Cao, Xia Yao, Yongguang Zhang, Liangyun Liu


WAFER: A new method to retrieve sun-induced fluorescence based on spectral wavelet decompositions. Remote Sensing of Environment 2023.

Veronika Oehl,Alexander Damm


The northernmost hyperspectral FLoX sensor dataset for monitoring of high-Arctic tundra vegetation phenology and Sun-Induced Fluorescence (SIF)

Hans Tømmervik, Tommaso Julitta, Lennart Nilsen, Taejin Park, Andreas Burkart, Katarzyna Ostapowicz, Stein Rune Karlsen, Frans-Jan Parmentier, Norbert Pirk, Jarle W. Bjerke


Empirical insights on the use of sun-induced chlorophyll fluorescence to estimate short-term changes in crop transpiration under controlled water limitation. ISPRS Journal of Photogrammetry and Remote Sensing. 2023

Kazi Rifat Ahmed, Eugenie Paul-Limoges, Uwe Rascher, Jan Hanus, Franco Miglietta, Roberto Colombo, Alessandro Peressotti, Andrea Genangeli, Alexander Damm


Simulating Global Dynamic Surface Reflectances for Imaging Spectroscopy Spaceborne Missions: LPJ-PROSAIL. Journal of Geophysical Research: Biogeosciences 2023.

Benjamin Poulter, Bryce Currey, Leonardo Calle, Alexey N. Shiklomanov, Cibele H. Amaral, E. N. Jack Brookshire, Petya Campbell, Adam Chlus, Kerry Cawse-Nicholson, Fred Huemmrich, Charles E. Miller, Kimberley Miner, Zoe Pierrat, Ann M. Raiho, David Schimel, Shawn Serbin, William K. Smith, Natasha Stavros, Jochen Stutz, Phil Townsend, David R. Thompson, Zhen Zhang


Contributions of the understory and midstory to total canopy solar-induced chlorophyll fluorescence in a ground-based study in conjunction with seasonal gross primary productivity in a cool-temperate deciduous broadleaf forest. Remote sensing of Environment 2023.

Tomoki Morozumi, Tomomichi Kato, Hideki Kobayashi, Yuma Sakai, Naohisa Nakashima, Kanokrat Buareal, Kenlo Nishida Nasahara, Tomoko Kawaguchi Akitsu, Shohei Murayama, Hibiki M. Noda, Hiroyuki Muraoka


Iterative design of a high light throughput cosine receptor fore optic for unattended proximal remote sensing. Journal of Applied Remote Sensing. 2022.

Andreas Burkart, Mitchell Kennedy, Paul Näthe, Tommaso Julitta


Retrieval of chlorophyll fluorescence from a large distance using oxygen absorption bands. Remote Sensing of Environment 2023.

Christiaan van der Tol, Tommaso Julitta, Peiqi Yang, Neus Sabater, Ilja Reiter, Marin Tudoroiu, Dirk Schuettemeyer, Matthias Drusch


A precise method unaffected by atmospheric reabsorption for ground-based retrieval of red and far-red sun-induced chlorophyll fluorescence. Agricultural and Forest Meteorology 2022.

Paul Naethe, Tommaso Julitta, Christine Yao-Yun Chang, Andreas Burkart, Mirco Migliavacca, Luis Guanter, Uwe Rascher


Harmonizing solar induced fluorescence across spatial scales, instruments, and extraction methods using proximal and airborne remote sensing: A multi-scale study in a soybean field. Remote Sensing of Environment 2022.

Ran Wang, John A. Gamon, Gabriel Hmimina, Sergio Cogliati, Arthur I. Zygielbaum, Timothy J. Arkebauer, Andrew Suyker


A novel hybrid machine learning phasor-based approach to retrieve a full set of solar-induced fluorescence metrics and biophysical parameters. Remote Sensing of Environment 2022.

R. Scodellaro, I. Cesana, L. D'Alfonso, M. Bouzin, M. Collini, G. Chirico, R.Colombo, F. Miglietta, M. Celesti, D. Schuettemeyer, S. Cogliati, L. Sironi


Physiological dynamics dominate the response of canopy far-red solar-induced fluorescence to herbicide treatment. Agricultural and Forest Meteorology 2022.

Linsheng Wu, XiaokangZhang, Micol Rossini, Yunfei Wu, Zhaoying Zhang, Yongguang Zhang


Towards consistent assessments of in situ radiometric measurements for the validation of fluorescence satellite missions. Remote Sensing of Environment 2022.

Bastian Buman, Andreas Hueni, Roberto Colombo, Sergio Cogliati, Marco Celesti, Tommaso Julitta, Andreas Burkart, Bastian Siegmann, Uwe Rascher, Matthias Drusch, Alexander Damm


Remote sensing of sun-induced chlorophyll-a fluorescence in inland and coastal waters: Current state and future prospects. Remote Sensing of Environment 2022.

Remika S.Gupana, Daniel Odermatt, Ilaria Cesana, Claudia Giardino, Ladislav Nedbal, Alexander Damm


Response times of remote sensing measured sun-induced chlorophyll fluorescence, surface temperature and vegetation indices to evolving soil water limitation in a crop canopy. Remote Sensing of Environment 2022.

A.Damm, S.Cogliati, R.Colombo, L.Fritsche, A.Genangeli, L.Genesio, J.Hanus, A.Peressotti, P.Rademske, U.Rascher, D.Schuettemeyer, B.Siegmann, J.Sturm, F.Miglietta


Heatwave breaks down the linearity between sun-induced fluorescence and gross primary production. New Phytologist 2021.

David Martini,Karolina Sakowska, Georg Wohlfahrt, Javier Pacheco-Labrador, Christiaan van der Tol, Albert Porcar-Castell, Troy S. Magney, Arnaud Carrara, Roberto Colombo, Tarek S. El-Madany, Rosario Gonzalez-Cascon, María Pilar Martín, Tommaso Julitta, Gerardo Moreno, Uwe Rascher, Markus Reichstein, Micol Rossini, Mirco Migliavacca


NIRVP: A robust structural proxy for sun-induced chlorophyll fluorescence and photosynthesis across scales. Remote Sensing of Environment 2022.

Benjamin Dechant, Youngryel Ryu, Grayson Badgle, Philipp Köhler, Uwe Rascher, Mirco Migliavacca, Yongguang Zhang, Giulia Tagliabue, Kaiyu Guan, Micol Rossini, Yves Goulas, Yelu Zeng, Christian Frankenberg, Joseph A.Berry


Constraining water limitation of photosynthesis in a crop growth model with sun-induced chlorophyll fluorescence. Remote Sensing of Environment, 2021

S.De Cannière, M.Herbst, H.Vereecken, P.Defourny, F.Jonard


Downscaling of far-red solar-induced chlorophyll fluorescence of different crops from canopy to leaf level using a diurnal data set acquired by the airborne imaging spectrometer HyPlant. Remote sensing of environment 2021.

Bastian Siegmann, Maria Pilar Cendrero-Mateo, Sergio Cogliati, Alexander Damm, John Gamon, David Herrera, Christoph Jedmowski, Laura Verena Junker-Frohn, Thorsten Kraska, Onno Muller, Patrick Rademske, Christiaan van der Tol, Juan Quiros-Vargas, Peiqi Yang, Uwe Rascher.


Practical approaches for normalizing directional solar-induced fluorescence to a standard viewing geometry. Remote Sensing of Environment, 2021

Dalei Hao,Yelu Zeng, Han Qiu, Khelvi Biriukova, Marco Celesti, Mirco Migliavacca, Micol Rossini, Ghassem R. Asrar, Min Chen


Differential responses in a Mediterranean citrus orchard to two heatwave intensities is identified by combining measurements of fluorescence, carbonyl sulfide (COS), and CO2 uptake. New Phytologist 2021.

Amnon Cochavi, Madi Amer, Rafael Stern, Fyodor Tatarinov, Mirco Migliavacca, Dan Yakir


Assessing the contribution of understory sun-induced chlorophyll fluorescence through 3-D radiative transfer modelling and field data. Remote Sensing of Environment. 2021

A. Hornero, P.R.J. North, P.J. Zarco-Tejada, U. Rascher, M.P. Martín, M. Migliavacca, R. Hernandez-Clemente


Concepts and Applications of Chlorophyll Fluorescence: A Remote Sensing Perspective. Geospatial Technologies for Crops and Soils. Springer 2021.

Choudhary K.K., Chakraborty A., Kumari M.


Diurnal dynamics of non-photochemical quenching in Arabidopsis npq mutants assessed by solar-induced fluorescence and reflectance measurements in the field. New Phytologist. 2020

K. Acebron,S. Matsubara,C. Jedmowski,D. Emin, O. Muller and U. Rascher


CloudRoots: integration of advanced instrumental techniques and process modelling of sub-hourly and sub-kilometre land–atmosphere interactions, Biogeosciences. 2020

Vilà-Guerau de Arellano, J., Ney, P., Hartogensis, O., de Boer, H., van Diepen, K., Emin, D., de Groot, G., Klosterhalfen, A., Langensiepen, M., Matveeva, M., Miranda-García, G., Moene, A. F., Rascher, U., Röckmann, T., Adnew, G., Brüggemann, N., Rothfuss, Y., and Graf, A.


Fluorescence Correction Vegetation Index (FCVI): A physically based reflectance index to separate physiological and non-physiological information in far-red sun-induced chlorophyll fluorescence. Remote Sensing of Environment, 2020

Peiqi Yang, Christiaan van der Tol, Petya K.E.Campbell, Elizabeth M.Middleton


Reduction of structural impacts and distinction of photosynthetic pathways in a global estimation of GPP from space-borne solar-induced chlorophyll fluorescence. Remote Sensing of Environment. 2020

Zhaoying Zhanga, Yongguang Zhanga, Albert Porcar-Castell, Joanna Joiner, Luis Guanter, Xi Yang, Mirco Migliavacca, Weimin Ju, Zhigang Sun, Shiping Chen, David Martini, Qian Zhang, Zhaohui Li, James Cleverly, Hezhou Wang, Yves Goulas


Unmanned Aerial Systems (UAS)-Based Methods for Solar Induced Chlorophyll Fluorescence (SIF) Retrieval with Non-Imaging Spectrometers: State of the Art. Remote Sensing 2020

Juan Quirós Vargas,Juliane Bendig,Alasdair Mac Arthur,Andreas Burkart,Tommaso Julitta,Kadmiel Maseyk,Rick Thomas 7,Bastian Siegmann,Micol Rossini, Marco Celesti, Dirk Schüttemeyer, Thorsten Kraska, Onno Muller and Uwe Rascher


Effects of varying solar-view geometry and canopy structure on solar-induced chlorophyll fluorescence and PRI

K. Biriukova, M. Celesti, A. Evdokimova, J. Pacheco-Labrador, T. Julitta, M. Migliavacca, C. Giardino, F. Miglietta, R. Colombo, C. Panigada, M. Rossini


Remote sensing of solar-induced chlorophyll fluorescence (SIF) in vegetation: 50 years of progress

G. H.Mohammed, R. Colombo, E. M.Middleton, U. Rascher, C. van der Tol, L. Nedbald, Y. Goulas, O. Pérez-Priego, A. Damm, M. Meroni, J. Joiner, S. Cogliati, W. Verhoef, Z. Malenovskýk, J. Gastellu-Etchegorry, J. R. Miller, L. Guantern, J. Moreno … P.J.Zarco-Tejada.


Diurnal and Seasonal Variations in Chlorophyll Fluorescence Associated with Photosynthesis at Leaf and Canopy Scales. Remote Sensing. 2019

Petya K. E. Campbell, Karl F. Huemmrich, Elizabeth M. Middleton, Lauren A. Ward, Tommaso Julitta, Craig S. T. Daughtry, Andreas Burkart, Andrew L. Russ and William P. Kustas


Sun-induced fluorescence and gross primary productivity during a heat wave. Scientific Reports. volume 8, Article number: 14169 (2018)

G. Wohlfahrt, K. Gerdel, M. Migliavacca, E. Rotenberg, F. Tatarinov, J. Müller, A. Hammerle, T. Julitta, F. M. Spielmann & D. Yakir


A Spectral Fitting Algorithm to Retrieve the Fluorescence Spectrum from Canopy Radiance

Sergio Cogliati, Marco Celesti, Ilaria Cesana, Franco Miglietta, Lorenzo Genesio, Tommaso Julitta, Dirk Schuettemeyer, Matthias Drusch, Uwe Rascher, Pedro Jurado and Roberto Colombo


Sun-Induced Chlorophyll Fluorescence I: Instrumental Considerations for Proximal Spectroradiometers

Javier Pacheco-Labrador, Andreas Hueni, Laura Mihai, Karolina Sakowska, Tommaso Julitta, Joel Kuusk, Dan Sporea, Luis Alonso, Andreas Burkart, M. Pilar Cendrero-Mateo, Helge Aasen, Yves Goulas , Alasdair Mac Arthur


Sun-Induced Chlorophyll Fluorescence II: Review of Passive Measurement Setups, Protocols, and Their Application at the Leaf to Canopy Level

H. Aasen, S. Van Wittenberghe, N. Sabater Medina, A. Damm, Y. Goulas, S. Wieneke, A. Hueni, Z. Malenovský, L. Alonso, J. Pacheco-Labrador, M. Pilar Cendrero-Mateo, E. Tomelleri, A. Burkart, S. Cogliati, U. Rascher, A. Mac Arthur


Sun-Induced Chlorophyll Fluorescence III: Benchmarking Retrieval Methods and Sensor Characteristics for Proximal Sensing

M. Pilar Cendrero-Mateo, Sebastian Wieneke, Alexander Damm, Luis Alonso, Francisco Pinto, Jose Moreno, Luis Guanter, Marco Celesti, Micol Rossini, Neus Sabater, Sergio Cogliati, Tommaso Julitta, Uwe Rascher, Yves Goulas, Helge Aasen, Javier Pacheco-Labrador, Alasdair Mac Arthur


An R Package for Field Spectroscopy: From System Characterization to Sun-Induced Chlorophyll Fluorescence Retrieval. 17-19 January 2017, ESA ESRIN, Frascati (Rome), Italy.

Julitta T. Wutzler T. Rossini M. Colombo R. Cogliati S. Meroni M., Burkart A. Migliavacca M.

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Characterisation of reflectance and chlorophyll fluorescence anisotropy – defining requirements for an experimental setup. Geophysical Research Abstracts, vol. 20, EGU2018-16936, 2018. EGU General Assembly 2018

Biriukova K. Julitta T. Celesti M. Panigada C. Evdokimov A. Migliavacca M. Rossini M

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Accurate measurements of fluorescence in the O2A and O2B band using the FloX spectroscopy system – results and prospects. Potsdam Greenhouse Gas Workshop, From Photosystems to Ecosystems 24 – 26 October 2017.

Julitta T. Burkart A. Colombo R. Rossini M. Schickling A. Migliavacca M. Cogliati S. Wutzler T. Rascher U.

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Exploiting top of Canopy Sun Induced Chlorophyll Fluorescence by the FloX. From Instrument performance to data processing. OPTIMISE COST Action Final Meeting. 21-23 February 2018, Sofia (Bulgaria)

Julitta T. Burkart A. Colombo R. Rossini M. Schickling A. Migliavacca M. Cogliati S. Wutzler T. Näthe P. Rascher U.

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