The Earth Photosynthesis Imaging Constellation: Measuring Photosynthesis with a cubesat platform

In response to NASA's Earth Venture Instrument-2 call, we proposed the Earth Photosynthesis Imaging Constellation (EPIC) mission. With EPIC, we will, for the first time, be able to provide the scientific community with global, spatially, and temporally explicit estimates of Photosynthesis, also known as Gross Primary Production (GPP) directly from satellite observations. Understanding the significance of terrestrial GPP for the global carbon, water, and energy balance, as well as its spatiotemporal dynamics is one of the key goals of Earth system science. Our proposed method is based on first principles of plant physiology and radiative transfer theory and has been demonstrated by the science team members in theoretical and experimental research. We expect EPIC to fundamentally change and improve our understanding of global photosynthesis and provide entirely new avenues for modeling and predicting Earth system behavior globally.The EPIC mission consists of four, 3-axis stabilized 6U CubeSats flown in pairs to enable multi-angle measurements. The two pairs may be launched on the same launch vehicle or on separate vehicles as necessitated by availability and destination orbits. If launched on the same vehicle, the two pairs can be spaced out via differential drag separation within a matter of months. To lower overall spacecraft costs, the CubeSats leverage existing off the shelf technologies as much as possible. Each EPIC spacecraft host an Integrated Vegetation Interferometer Spectrometer (IVIS) instrument. The highly compact IVIS consists of two primary sensors with separate, co-aligned optics: a spatial-heterodyne-spectrometer (IVIS/SHS) and hyperspectral imager (IVIS/HSI). The IVIS/HSI was specifically designed to implement a multi-angle measurement technique to determine the photosynthetic rate of vegetation (hereafter Hall-Hilker technique); the IVIS/SHS is designed to narrowly peer into a Fraunhofer line at high spectral resolution to obtain solar induced chlorophyll fluorescence (hereafter referred to as Joiner-Frankenberg technique). This paper will provide a description of the EPIC mission and science goals, details of the EPIC team, details of the science techniques to be implemented, and demonstrate how the design of the proposed EPIC CubeSat spacecraft and integrated IVIS instrument enable the proposed science at a fraction of the cost of larger systems.

[1]  R. Schnur,et al.  Climate-carbon cycle feedback analysis: Results from the C , 2006 .

[2]  T. A. Black,et al.  Separating physiologically and directionally induced changes in PRI using BRDF models , 2008 .

[3]  D. Sims,et al.  Relationships between leaf pigment content and spectral reflectance across a wide range of species, leaf structures and developmental stages , 2002 .

[4]  Jason Andrews,et al.  Spaceflight Networks – A New Paradigm for Cost Effective Satellite Communications , 2014 .

[5]  Lawrence A. Corp,et al.  Filling-In of Broad Far-Red Solar Lines by Terrestrial Fluorescence and Atmospheric Raman Scattering as Detected by SCIAMACHY Satellite Measurements , 2011 .

[6]  K Raschke,et al.  Topography of photosynthetic activity of leaves obtained from video images of chlorophyll fluorescence. , 1989, Plant physiology.

[7]  T. A. Black,et al.  The use of remote sensing in light use efficiency based models of gross primary production: a review of current status and future requirements. , 2008, The Science of the total environment.

[8]  E. Middleton,et al.  Filling-in of near-infrared solar lines by terrestrial fluorescence and other geophysical effects: simulations and space-based observations from SCIAMACHY and GOSAT , 2012 .

[9]  Corinne Le Quéré,et al.  Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks , 2007, Proceedings of the National Academy of Sciences.

[10]  B. Demmig‐Adams,et al.  Regulation of Photosynthetic Light Energy Capture, Conversion, and Dissipation in Leaves of Higher Plants , 1994 .

[11]  C. Tucker,et al.  Remote sensing of tropical ecosystems: Atmospheric correction and cloud masking matter , 2012 .

[12]  Corinne Le Quéré,et al.  Trends in the sources and sinks of carbon dioxide , 2009 .

[13]  C. Frankenberg,et al.  Forest productivity and water stress in Amazonia: observations from GOSAT chlorophyll fluorescence , 2013, Proceedings of the Royal Society B: Biological Sciences.

[14]  B. Demmig‐Adams,et al.  The role of xanthophyll cycle carotenoids in the protection of photosynthesis , 1996 .

[15]  Thomas Hilker,et al.  PHOTOSYNSAT, photosynthesis from space: Theoretical foundations of a satellite concept and validation from tower and spaceborne data , 2011 .

[16]  Thomas Hilker,et al.  Remote sensing of photosynthetic light-use efficiency across two forested biomes: Spatial scaling , 2010 .

[17]  R. DeFries,et al.  Effects of Land Cover Conversion on Surface Climate , 2002 .

[18]  N. Coops,et al.  Multi-Angle Remote Sensing of Forest Light Use Efficiency , 2007 .

[19]  Atul K. Jain,et al.  A model-data comparison of gross primary productivity: Results from the North American Carbon Program site synthesis , 2012 .

[20]  Joseph A. Berry,et al.  Quantum efficiency of Photosystem II in relation to ‘energy’-dependent quenching of chlorophyll fluorescence , 1987 .

[21]  T. A. Black,et al.  Inferring terrestrial photosynthetic light use efficiency of temperate ecosystems from space , 2011 .

[22]  Philip Lewis,et al.  Retrieval and global assessment of terrestrial chlorophyll fluorescence from GOSAT space measurements , 2012 .

[23]  Thomas Hilker,et al.  An assessment of photosynthetic light use efficiency from space: Modeling the atmospheric and directional impacts on PRI reflectance , 2009 .

[24]  B. Demmig‐Adams,et al.  Photoprotection and Other Responses of Plants to High Light Stress , 1992 .

[25]  Gary Crum,et al.  Expanding CubeSat Capabilities with a Low Cost Transceiver , 2014 .

[26]  Christian Frankenberg,et al.  Disentangling chlorophyll fluorescence from atmospheric scattering effects in O2 A‐band spectra of reflected sun‐light , 2011 .

[27]  C. Field,et al.  A narrow-waveband spectral index that tracks diurnal changes in photosynthetic efficiency , 1992 .

[28]  Luis Alonso,et al.  Remote sensing of solar-induced chlorophyll fluorescence: Review of methods and applications , 2009 .

[29]  D. Randall,et al.  A Revised Land Surface Parameterization (SiB2) for Atmospheric GCMS. Part I: Model Formulation , 1996 .

[30]  E. Middleton,et al.  First observations of global and seasonal terrestrial chlorophyll fluorescence from space , 2010 .