Project Funding: 2008 - 2014

NRA: 2009 NASA: The Science of Terra and Aqua   

Funded by NASA

Abstract:
2011 Abstract: The goal of this proposal is to use data from the Multiangle Imaging SpectroRadiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) to map changes in aboveground standing live dry biomass in trees and shrubs in the southwestern United States for the period 2000-2009. It will leverage an innovative approach developed in previous Earth Observing System projects that exploits structural rather than spectral signals in bidirectional reflectance factor (BRF) data: this has demonstrated success in both estimating shrub abundance and primary forest canopy parameters at ~250 m with good accuracy. The method is predicated on the strong structural signal available in MISR and MODIS BRF data: both instruments view far from nadir, introducing reflectance anisotropy that can be exploited to predict understory density and invert geometric-optical (GO) models for crown cover and mean canopy height. Aboveground standing live dry biomass estimated using both parameters is likely to be more accurate than estimates based on spectral measures because canopy height is taken into account. The proposed project builds on advances in GO model inversion behavior stemming from recent efforts to assess retrievals against high resolution discrete return lidar data and orthophotography - rather than against moderate or medium resolution data products - and on a new and efficient automated method for obtaining high resolution validation data: the Canopy Analysis with Panchromatic Imagery (CANAPI) algorithm. This is able to delineate crowns using only high resolution panchromatic imagery and provide accurate measures of crown cover for the large (>250 m^2) areas needed for validation of moderate resolution products. Crown cover estimates are also needed to improve background sub-model calibration that is critical to the accuracy and precision of cover and height retrievals obtained via GO model inversion. Reference data will also include ground survey data for a number of well-characterized sites and lidar canopy heights where available. The approach has several advantages: MISR and MODIS cover large areas efficiently, allowing evaluation of trajectories through time from 2000; MISR views away from the solar principal plane allowing the background and upper canopy contributions to be isolated; explicitly acknowledging and exploiting structural effects provides potentially less ambiguous measures than spectral indices; and output maps include shrubs as well as trees. The ability to map understory density at large scales using multiangle imagery has been identified by other research groups and points towards the realization of synergies with data from lidar and radar sensors (e.g., between the DESDyNI and ACE missions that will fly active instruments and a multiangle polarimeter, respectively). This research is important because disturbances that are likely to be related to changing climatic conditions - owing to global warming - appear to be playing increasingly prominent roles in defining aboveground carbon stocks in the southwestern US. These include unusually extensive and severe losses in forest cover from a modified fire regime; unusually extensive and severe insect outbreaks (pine and spruce beetle); and continued woody encroachment into former desert grasslands. Increasing shrub abundance in desert grasslands has already reduced the ability of the land to support a viable livestock economy in many places and is also important in terms of ecosystem structure and function and feedbacks to climate. As well as leveraging recent advances in exploiting EOS data using this novel modeling framework, this research also addresses imperatives within NASA's Carbon Cycle and Ecosystems and Terrestrial Ecology programs to further research quantifying changes in aboveground standing biomass from disturbance and recovery, and to address measurement uncertainty in low biomass regions. 2008-2011 Title: A new approach for mapping woody plants in the southwestern United States using NASA Earth Observing System Data Update 2008: the project 'A new approach for mapping woody plants in the southwestern United States using NASA Earth Observing System Data' extends the advances made in the earlier project. We are making significant progress in the mapping of forest and desert grassland woody canopies by interpreting multiangle data from MISR and MODIS through a hybrid geometric-optical model. Findings from both projects are described at: http://csam.montclair.edu/~chopping/wood/ This work is important because moderate resolution (250m²) maps of woody plant canopy crown shape, fractional cover, and mean canopy height can be obtained at the regional scale, more reliable estimates of biomass losses from wildfire and other disturbance processes will be available, since the canopy 3-D structure is taken into account . These products may be useful for the decade 2000-2010 during which maps from lidar instruments were not available; and thereafter in tandem with products from active instruments. Previously (2007): In tandem with the ongoing world-wide increase in the abundance of woody plants within former grasslands, desert grasslands throughout the southwestern U.S. have experienced a dramatic increase in the abundance of shrubs since the end of the 19th century. The region thus provides an adequate subject for the development of remote sensing and modeling methods which will be useful at global scales and in other regions. We propose to estimate carbon pools in this region using remotely-sensed inputs from the NASA Earth Observing System satellites Terra and Aqua. We are working to refine mapping of vegetation through improved plant community type differentiation, estimating contributions from soil, shrub and grass components and provision of structural measures. This addresses three aspects of the problem of estimating C pools: large differences in total C storage in different plant communities; the need to reliably estimate the areal proportions of soil, grass and shrubs; and the need to obtain measures of canopy structure over large areas. We are working towards these goals using multi-angle spectral reflectance data and derived parameters and metrics from the MISR and MODIS instruments. The approach is based on the premise that incorporating multi-angle measures in plant community type mapping results in substantial improvements in classification and mapping; that canopy heterogeneity is reflected in these data; and that useful canopy structure measures are available in the angular domain. From 2006, we began working at the regional scale and included maps of forest canopy parameters from MISR.

Publications:

Chopping, M., Moisen, G. G., Su, L., Laliberte, A., Rango, A., Martonchik, J. V., Peters, D. P. 2008. Large area mapping of southwestern forest crown cover, canopy height, and biomass using the NASA Multiangle Imaging Spectro-Radiometer. Remote Sensing of Environment. 112(5), 2051-2063. DOI: 10.1016/j.rse.2007.07.024

CHOPPING, M., SU, L., RANGO, A., MARTONCHIK, J., PETERS, D., LALIBERTE, A. 2008. Remote sensing of woody shrub cover in desert grasslands using MISR with a geometric-optical canopy reflectance model. Remote Sensing of Environment. 112(1), 19-34. DOI: 10.1016/j.rse.2006.04.023

Chopping, M. (2008), Terrestrial Applications of Multiangle Remote Sensing, in Advances in Land Remote Sensing: System, Modeling, Inversion and Applications, S. Liang, ed., Springer- Verlag, 95-144. ISBN 978-1-4020-6450-0

Su, L., Chopping, M. J., Rango, A., Martonchik, J. V., Peters, D. P. 2007. Support vector machines for recognition of semi-arid vegetation types using MISR multi-angle imagery. Remote Sensing of Environment. 107(1-2), 299-311. DOI: 10.1016/j.rse.2006.05.023

Su, L., Chopping, M. J., Rango, A., Martonchik, J. V., Peters, D. P. C. 2007. Differentiation of semi-arid vegetation types based on multi-angular observations from MISR and MODIS. International Journal of Remote Sensing. 28(6), 1419-1424. DOI: 10.1080/01431160601085995

Chopping, M. J., Su, L., Laliberte, A., Rango, A., Peters, D. P. C., Martonchik, J. V. 2006. Mapping woody plant cover in desert grasslands using canopy reflectance modeling and MISR data. Geophysical Research Letters. 33(17). DOI: 10.1029/2006GL027148

Chopping, M., Su, L., Laliberte, A., Rango, A., Peters, D. P., Kollikkathara, N. 2006. Mapping shrub abundance in desert grasslands using geometric-optical modeling and multi-angle remote sensing with CHRIS/Proba. Remote Sensing of Environment. 104(1), 62-73. DOI: 10.1016/j.rse.2006.04.022

2015 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• Mapping Aboveground Biomass in the Western US with the Multiangle Imaging Spectro-Radiometer   --   (Mark James Chopping, Zhuosen Wang, Michael Bull, Rocio Duchesne)   [abstract]   [poster]

2011 NASA Carbon Cycle & Ecosystems Joint Science Workshop Poster(s)

• Forest Cover and Height in Topographically Complex Landscapes from MISR Assessed with High Quality Reference Data   --   (Mark James Chopping, Malcolm North, Jiquan Chen, Crystal Schaaf, John V Martonchik, Michael Bull, Bryan Blair, Michelle Hofton)   [abstract]   [poster]

2010 NASA Terrestrial Ecology Science Team Meeting Poster(s)

• CANAPI: Canopy Analysis with Panchromatic Imagery for Validation of Moderate Resolution Canopy Structure Products   --   (Mark James Chopping, Xiaoyuan Yang, Crystal Schaaf, Alan Strahler)   [abstract]   [poster]
• Canopy Height, Crown Cover, and Aboveground Standing Live Biomass in the Southwestern United States from MISR, 2000 and 2009.   --   (Mark James Chopping, Sawahiko Shimada, Michael Bull, John Martonchik)   [abstract]   [poster]

2008 NASA Carbon Cycle & Ecosystems Joint Science Workshop Posters

• Using MISR to Map Woody Plant Canopy Crown Cover, Height, and Biomass   --   (Mark Chopping, John Martonchik, Michael Bull, Gretchen Moisen, Barry Wilson, Albert Rango)   [abstract]   [poster]

More details may be found in the following project profile(s):

• NASA Terrestrial Ecology (TE) Project Profile
• North American Carbon Program (NACP) Project Profile