{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T17:35:32Z","timestamp":1776274532177,"version":"3.50.1"},"reference-count":57,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2021,5,9]],"date-time":"2021-05-09T00:00:00Z","timestamp":1620518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["J. Imaging"],"abstract":"<jats:p>Utilization of the Bidirectional Reflectance Distribution Function (BRDF) model parameters obtained from the multi-angular remote sensing is one of the approaches for the retrieval of vegetation structural information. In this research, the potential of multi-angular vegetation indices, formulated by the combination of multi-spectral reflectance from different view angles, for the retrieval of forest above-ground biomass was assessed in the New England region. The multi-angular vegetation indices were generated by the simulation of the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF\/Albedo Model Parameters Product (MCD43A1 Version 6)-based BRDF parameters. The effects of the seasonal (spring, summer, autumn, and winter) composites of the multi-angular vegetation indices on the above-ground biomass, the angular relationship of the spectral reflectance with above-ground biomass, and the interrelationships between the multi-angular vegetation indices were analyzed. Among the existing multi-angular vegetation indices, only the Nadir BRDF-adjusted NDVI and Hot-spot incorporated NDVI showed significant relationship (more than 50%) with the above-ground biomass. The Vegetation Structure Index (VSI), newly proposed in the research, performed in the most efficient way and explained 64% variation of the above-ground biomass, suggesting that the right choice of the spectral channel and observation geometry should be considered for improving the estimates of the above-ground biomass. In addition, the right choice of seasonal data (summer) was found to be important for estimating the forest biomass, while other seasonal data were either insensitive or pointless. The promising results shown by the VSI suggest that it could be an appropriate candidate for monitoring vegetation structure from the multi-angular satellite remote sensing.<\/jats:p>","DOI":"10.3390\/jimaging7050084","type":"journal-article","created":{"date-parts":[[2021,5,9]],"date-time":"2021-05-09T21:32:46Z","timestamp":1620595966000},"page":"84","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Vegetation Structure Index (VSI): Retrieving Vegetation Structural Information from Multi-Angular Satellite Remote Sensing"],"prefix":"10.3390","volume":"7","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5706-4417","authenticated-orcid":false,"given":"Ram C.","family":"Sharma","sequence":"first","affiliation":[{"name":"Department of Informatics, Tokyo University of Information Sciences, 4-1 Onaridai, Wakaba-ku, Chiba 265-8501, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Jenkins, J.C., Chojnacky, D.C., Heath, L.S., and Birdsey, R.A. (2004). Comprehensive Database of Diameter-Based Biomass Regressions for North American Tree Species, United States Department of Agriculture, Forest Service, Northeastern Research Station.","DOI":"10.2737\/NE-GTR-319"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"409","DOI":"10.1098\/rstb.2003.1425","article-title":"Error Propagation and Scaling for Tropical Forest Biomass Estimates","volume":"359","author":"Chave","year":"2004","journal-title":"Philos. Trans. R. Soc. Lond. Ser. B Biol. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1109\/TGRS.1986.289647","article-title":"Directional Reflectance Distributions of a Hardwood and Pine Forest Canopy","volume":"GE-24","author":"Kimes","year":"1986","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"276","DOI":"10.1109\/36.134078","article-title":"Geometric-Optical Bidirectional Reflectance Modeling of the Discrete Crown Vegetation Canopy: Effect of Crown Shape and Mutual Shadowing","volume":"30","author":"Li","year":"1992","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/S0034-4257(99)00032-2","article-title":"Structure Analysis and Classification of Boreal Forests Using Airborne Hyperspectral BRDF Data from ASAS","volume":"69","author":"Sandmeier","year":"1999","journal-title":"Remote Sens. Environ."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/S0034-4257(97)00070-9","article-title":"Analyzing the Effect of Structural Variability and Canopy Gaps on Forest BRDF Using a Geometric-Optical Model","volume":"62","author":"Gerard","year":"1997","journal-title":"Remote Sens. Environ."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"946","DOI":"10.1109\/36.508411","article-title":"Three-Dimensional Forest Light Interaction Model Using a Monte Carlo Method","volume":"34","author":"North","year":"1996","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/S0034-4257(96)00245-3","article-title":"A Study of Reflectance Anisotropy and Canopy Structure Using a Simple Empirical Model","volume":"61","author":"Walthall","year":"1997","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/0034-4257(94)90091-4","article-title":"Retrieval of Surface BRDF from Multiangle Remotely Sensed Data","volume":"50","author":"Liang","year":"1994","journal-title":"Remote Sens. Environ."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1109\/TGRS.1985.289389","article-title":"Geometric-Optical Modeling of a Conifer Forest Canopy","volume":"GE-23","author":"Li","year":"1985","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/0034-4257(91)90089-O","article-title":"A Hotspot Model for Leaf Canopies","volume":"38","author":"Jupp","year":"1991","journal-title":"Remote Sens. Environ."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"362","DOI":"10.1016\/j.rse.2006.05.021","article-title":"Application to MISR Land Products of an RPV Model Inversion Package Using Adjoint and Hessian Codes","volume":"107","author":"Lavergne","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"20455","DOI":"10.1029\/92JD01411","article-title":"A Bidirectional Reflectance Model of the Earth\u2019s Surface for the Correction of Remote Sensing Data","volume":"97","author":"Roujean","year":"1992","journal-title":"J. Geophys. Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1080\/02757250009532388","article-title":"Contributions of Multi-view Angle Remote Sensing to Land-surface and Biogeochemical Research","volume":"18","author":"Asner","year":"2000","journal-title":"Remote Sens. Rev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2943","DOI":"10.1016\/j.rse.2010.08.031","article-title":"Forest Structure and Aboveground Biomass in the Southwestern United States from MODIS and MISR","volume":"115","author":"Chopping","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"80","DOI":"10.1016\/j.rse.2005.06.008","article-title":"Variability of Biome Reflectance Directional Signatures as Seen by POLDER","volume":"98","author":"Bacour","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"2627","DOI":"10.1016\/j.rse.2007.12.005","article-title":"Multi-Angular Reflectance Properties of a Hemiboreal Forest: An Analysis Using CHRIS PROBA Data","volume":"112","author":"Rautiainen","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2184","DOI":"10.1016\/j.rse.2011.04.012","article-title":"Variability in Surface BRDF at Different Spatial Scales (30 m\u2013500 m) over a Mixed Agricultural Landscape as Retrieved from Airborne and Satellite Spectral Measurements","volume":"115","author":"Gatebe","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Sharma, R., and Hara, K. (2018). Characterization of Vegetation Physiognomic Types Using Bidirectional Reflectance Data. Geosciences, 8.","DOI":"10.3390\/geosciences8110394"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1016\/j.isprsjprs.2016.10.002","article-title":"Examining View Angle Effects on Leaf N Estimation in Wheat Using Field Reflectance Spectroscopy","volume":"122","author":"Song","year":"2016","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1782","DOI":"10.1080\/01431161.2017.1404165","article-title":"Influence of the Canopy BRDF Characteristics and Illumination Conditions on the Retrieval of Solar-Induced Chlorophyll Fluorescence","volume":"39","author":"Liu","year":"2018","journal-title":"Int. J. Remote Sens."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/0034-4257(90)90017-G","article-title":"Bidirectional Measurements of Surface Reflectance for View Angle Corrections of Oblique Imagery","volume":"32","author":"Jackson","year":"1990","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"684","DOI":"10.1109\/36.297985","article-title":"Sun and View Angle Corrections on Reflectances Derived from NOAA\/AVHRR Data","volume":"32","author":"Leroy","year":"1994","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2341","DOI":"10.1016\/j.rse.2007.11.001","article-title":"Angular Sensitivity Analysis of Vegetation Indices Derived from CHRIS\/PROBA Data","volume":"112","author":"Verrelst","year":"2008","journal-title":"Remote Sens. Environ."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1109\/36.841980","article-title":"An Algorithm for the Retrieval of Albedo from Space Using Semiempirical BRDF Models","volume":"38","author":"Lucht","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1016\/j.rse.2013.10.017","article-title":"An Anisotropic Flat Index (AFX) to Derive BRDF Archetypes from MODIS","volume":"141","author":"Jiao","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1016\/S0034-4257(03)00100-7","article-title":"Detecting Vegetation Structure Using a Kernel-Based BRDF Model","volume":"86","author":"Gao","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"736","DOI":"10.1016\/j.jqsrt.2010.06.004","article-title":"Canopy Spectral Invariants, Part 2: Application to Classification of Forest Types from Hyperspectral Data","volume":"112","author":"Schull","year":"2011","journal-title":"J. Quant. Spectrosc. Radiat. Transf."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"196","DOI":"10.1016\/j.rse.2006.12.015","article-title":"Spectral Invariants and Scattering across Multiple Scales from Within-Leaf to Canopy","volume":"109","author":"Lewis","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"6229","DOI":"10.1029\/1998JD200104","article-title":"Retrieval of Red Spectral Albedo and Bidirectional Reflectance Using AVHRR HRPT and GOES Satellite Observations of the New England Region","volume":"104","author":"Schaaf","year":"1999","journal-title":"J. Geophys. Res. Atmos."},{"key":"ref_31","unstructured":"Doll, C.N.H., Muller, J.-P., Schaaf, C., and Strahler, A.H. (2001, January 9\u20133). Feng Gao Mapping Urban Landcover Using the Bidirectional Reflectance Distribution Function BRDF\/Albedo Product from the Moderate Resolution Imaging Spectroradiometer (MODIS). Proceedings of the IGARSS 2001. Scanning the Present and Resolving the Future. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217), Sydney, NSW, Australia."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"21077","DOI":"10.1029\/95JD02371","article-title":"On the Derivation of Kernels for Kernel-Driven Models of Bidirectional Reflectance","volume":"100","author":"Wanner","year":"1995","journal-title":"J. Geophys. Res."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/S0034-4257(02)00091-3","article-title":"First Operational BRDF, Albedo Nadir Reflectance Products from MODIS","volume":"83","author":"Schaaf","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1016\/S0034-4257(98)00060-1","article-title":"Physical Mechanisms in Hyperspectral BRDF Data of Grass and Watercress","volume":"66","author":"Sandmeier","year":"1998","journal-title":"Remote Sens. Environ."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1016\/S0034-4257(01)00241-3","article-title":"Retrieval of Vegetation Clumping Index Using Hot Spot Signatures Measured by POLDER Instrument","volume":"79","author":"Lacaze","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1016\/j.rse.2005.05.003","article-title":"Global Mapping of Foliage Clumping Index Using Multi-Angular Satellite Data","volume":"97","author":"Chen","year":"2005","journal-title":"Remote Sens. Environ."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"322","DOI":"10.1016\/j.rse.2006.06.019","article-title":"View Angle Effects on Relationships between MISR Vegetation Indices and Leaf Area Index in a Recently Burned Ponderosa Pine Forest","volume":"107","author":"Pocewicz","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Cook, B., Dubayah, R., Griffith, P., Hall, F.G., Nelson, R., Ranson, J., Simard, M., Siqueira, P., and Strahler, A.H. (2011). NACP New England and Sierra National Forests Biophysical Measurements: 2008\u20132010. ORNL DAAC.","DOI":"10.3334\/ORNLDAAC\/1046"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"675","DOI":"10.1007\/s00468-012-0822-4","article-title":"Automated Extraction of Canopy Shadow Fraction Using Unmanned Helicopter-Based Color Vegetation Indices","volume":"27","author":"Sharma","year":"2013","journal-title":"Trees"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.isprsjprs.2012.12.006","article-title":"Estimation of Forest Canopy Structural Parameters Using Kernel-Driven Bi-Directional Reflectance Model Based Multi-Angular Vegetation Indices","volume":"78","author":"Sharma","year":"2013","journal-title":"Isprs J. Photogramm. Remote Sens."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"16315","DOI":"10.3390\/rs71215830","article-title":"Estimation of Alpine Forest Structural Variables from Imaging Spectrometer Data","volume":"7","author":"Fatehi","year":"2015","journal-title":"Remote Sens."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"208","DOI":"10.1016\/j.rse.2016.04.020","article-title":"Canopy Structural Attributes Derived from AVIRIS Imaging Spectroscopy Data in a Mixed Broadleaf\/Conifer Forest","volume":"182","author":"Huesca","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"281","DOI":"10.1016\/j.rse.2005.10.006","article-title":"Inversion of a Forest Reflectance Model to Estimate Structural Canopy Variables from Hyperspectral Remote Sensing Data","volume":"100","author":"Schlerf","year":"2006","journal-title":"Remote Sens. Environ."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Miraglio, T., Adeline, K., Huesca, M., Ustin, S., and Briottet, X. (2020). Joint Use of PROSAIL and DART for Fast LUT Building: Application to Gap Fraction and Leaf Biochemistry Estimations over Sparse Oak Stands. Remote Sens., 12.","DOI":"10.3390\/rs12182925"},{"key":"ref_45","first-page":"271","article-title":"Spectrodirectional Remote Sensing for the Improved Estimation of Biophysical and -Chemical Variables: Two Case Studies","volume":"6","author":"Schaepman","year":"2005","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1016\/j.rse.2008.10.003","article-title":"Detection of Foliage Conditions and Disturbance from Multi-Angular High Spectral Resolution Remote Sensing","volume":"113","author":"Hilker","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1505\/146554812802646602","article-title":"Review of Forestry Oriented Multi-Angular Remote Sensing Techniques","volume":"14","author":"Fassnachta","year":"2012","journal-title":"Int. Forest. Rev."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1016\/j.isprsjprs.2010.03.002","article-title":"Expanding Global Mapping of the Foliage Clumping Index with Multi-Angular POLDER Three Measurements: Evaluation and Topographic Compensation","volume":"65","author":"Pisek","year":"2010","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1007\/s00442-010-1901-0","article-title":"Tracking Plant Physiological Properties from Multi-Angular Tower-Based Remote Sensing","volume":"165","author":"Hilker","year":"2011","journal-title":"Oecologia"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"118","DOI":"10.1016\/j.rse.2011.12.008","article-title":"Global Clumping Index Map Derived from the MODIS BRDF Product","volume":"119","author":"He","year":"2012","journal-title":"Remote Sens. Environ."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"516","DOI":"10.1016\/S0034-4257(02)00150-5","article-title":"Multi-Angular Optical Remote Sensing for Assessing Vegetation Structure and Carbon Absorption","volume":"84","author":"Chen","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"301","DOI":"10.5589\/m10-050","article-title":"Predicting Leaf Area Index in Wheat Using Angular Vegetation Indices Derived from in Situ Canopy Measurements","volume":"36","author":"Wu","year":"2010","journal-title":"Can. J. Remote Sens."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Wang, Q., Pang, Y., Li, Z., Sun, G., Chen, E., and Ni-Meister, W. (2016). The Potential of Forest Biomass Inversion Based on Vegetation Indices Using Multi-Angle CHRIS\/PROBA Data. Remote Sens., 8.","DOI":"10.3390\/rs8110891"},{"key":"ref_54","doi-asserted-by":"crossref","unstructured":"Cui, L., Jiao, Z., Dong, Y., Sun, M., Zhang, X., Yin, S., Ding, A., Chang, Y., Guo, J., and Xie, R. (2019). Estimating Forest Canopy Height Using MODIS BRDF Data Emphasizing Typical-Angle Reflectances. Remote Sens., 11.","DOI":"10.3390\/rs11192239"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"202","DOI":"10.3390\/rs5010202","article-title":"Allometric Scaling and Resource Limitations Model of Tree Heights: Part 2. Site Based Testing of the Model","volume":"5","author":"Choi","year":"2013","journal-title":"Remote Sens."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"6566","DOI":"10.3390\/rs6076566","article-title":"Application of Physically-Based Slope Correction for Maximum Forest Canopy Height Estimation Using Waveform Lidar across Different Footprint Sizes and Locations: Tests on LVIS and GLAS","volume":"6","author":"Park","year":"2014","journal-title":"Remote Sens."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.rse.2015.12.005","article-title":"A Combined GLAS and MODIS Estimation of the Global Distribution of Mean Forest Canopy Height","volume":"174","author":"Wang","year":"2016","journal-title":"Remote Sens. Environ."}],"container-title":["Journal of Imaging"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2313-433X\/7\/5\/84\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:58:29Z","timestamp":1760162309000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2313-433X\/7\/5\/84"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,9]]},"references-count":57,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2021,5]]}},"alternative-id":["jimaging7050084"],"URL":"https:\/\/doi.org\/10.3390\/jimaging7050084","relation":{"has-preprint":[{"id-type":"doi","id":"10.20944\/preprints202102.0467.v1","asserted-by":"object"}]},"ISSN":["2313-433X"],"issn-type":[{"value":"2313-433X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,9]]}}}