TY - JOUR
T1 - Simulating Global Dynamic Surface Reflectances for Imaging Spectroscopy Spaceborne Missions
T2 - LPJ-PROSAIL
AU - Poulter, Benjamin
AU - Currey, Bryce
AU - Calle, Leonardo
AU - Shiklomanov, Alexey N.
AU - Amaral, Cibele H.
AU - Brookshire, E. N.Jack
AU - Campbell, Petya
AU - Chlus, Adam
AU - Cawse-Nicholson, Kerry
AU - Huemmrich, Fred
AU - Miller, Charles E.
AU - Miner, Kimberley
AU - Pierrat, Zoe
AU - Raiho, Ann M.
AU - Schimel, David
AU - Serbin, Shawn
AU - Smith, William K.
AU - Stavros, Natasha
AU - Stutz, Jochen
AU - Townsend, Phil
AU - Thompson, David R.
AU - Zhang, Zhen
N1 - Publisher Copyright:
© 2023 The Authors. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.
PY - 2023/1
Y1 - 2023/1
N2 - Spectroscopic reflectance data provide novel information on the properties of the Earth's terrestrial and aquatic surfaces. Until recently, imaging spectroscopy missions were dependent mainly on airborne instruments, such as the Next Generation Airborne Visible InfraRed Imaging Spectrometer (AVIRIS-NG), providing limited spatial and temporal observations. Currently, there is an emergence of spaceborne imaging spectroscopy missions, which require advances in end-to-end model support for traceability studies. To provide this support, the LPJ-wsl dynamic global vegetation model is coupled with the canopy radiative transfer model, PROSAIL, to generate global, gridded, daily visible to shortwave infrared (VSWIR) spectra (400–2,500 nm). LPJ-wsl variables are cross-walked to meet required PROSAIL parameters, which include leaf structure, chlorophyll a + b, brown pigment, equivalent water thickness, and dry matter content. Simulated spectra are compared to a boreal forest site, a temperate forest, managed grassland, a dryland and a tropical forest site using reflectance data from tower-mounted, aircraft, and spaceborne imagers. We find that canopy nitrogen and leaf-area index are the most uncertain variables in translating LPJ-wsl to PROSAIL parameters but at first order, LPJ-PROSAIL successfully simulates surface reflectance dynamics. Future work will optimize functional relationships required for improving PROSAIL parameters and include the development of the LPJ-model to represent improvements in leaf water content and canopy nitrogen. The LPJ-PROSAIL model is intended to support missions such as NASA's Surface Biology and Geology and subsequent modeled products related to the carbon cycle and hydrology.
AB - Spectroscopic reflectance data provide novel information on the properties of the Earth's terrestrial and aquatic surfaces. Until recently, imaging spectroscopy missions were dependent mainly on airborne instruments, such as the Next Generation Airborne Visible InfraRed Imaging Spectrometer (AVIRIS-NG), providing limited spatial and temporal observations. Currently, there is an emergence of spaceborne imaging spectroscopy missions, which require advances in end-to-end model support for traceability studies. To provide this support, the LPJ-wsl dynamic global vegetation model is coupled with the canopy radiative transfer model, PROSAIL, to generate global, gridded, daily visible to shortwave infrared (VSWIR) spectra (400–2,500 nm). LPJ-wsl variables are cross-walked to meet required PROSAIL parameters, which include leaf structure, chlorophyll a + b, brown pigment, equivalent water thickness, and dry matter content. Simulated spectra are compared to a boreal forest site, a temperate forest, managed grassland, a dryland and a tropical forest site using reflectance data from tower-mounted, aircraft, and spaceborne imagers. We find that canopy nitrogen and leaf-area index are the most uncertain variables in translating LPJ-wsl to PROSAIL parameters but at first order, LPJ-PROSAIL successfully simulates surface reflectance dynamics. Future work will optimize functional relationships required for improving PROSAIL parameters and include the development of the LPJ-model to represent improvements in leaf water content and canopy nitrogen. The LPJ-PROSAIL model is intended to support missions such as NASA's Surface Biology and Geology and subsequent modeled products related to the carbon cycle and hydrology.
KW - Surface Biology and Geology (SBG)
KW - dynamic global vegetation model
KW - imaging spectroscopy
KW - radiative transfer model
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U2 - 10.1029/2022JG006935
DO - 10.1029/2022JG006935
M3 - Article
AN - SCOPUS:85147148841
SN - 2169-8953
VL - 128
JO - Journal of Geophysical Research: Biogeosciences
JF - Journal of Geophysical Research: Biogeosciences
IS - 1
M1 - e2022JG006935
ER -