{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T04:15:20Z","timestamp":1783570520255,"version":"3.55.0"},"reference-count":98,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,21]],"date-time":"2021-11-21T00:00:00Z","timestamp":1637452800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"German Federal Ministry of Economic Affairs and Energy","award":["50EE1923"],"award-info":[{"award-number":["50EE1923"]}]},{"name":"European Research Council (ERC)","award":["ERC-2017-STG SENTIFLEX"],"award-info":[{"award-number":["ERC-2017-STG SENTIFLEX"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Non-photosynthetic vegetation (NPV) biomass has been identified as a priority variable for upcoming spaceborne imaging spectroscopy missions, calling for a quantitative estimation of lignocellulosic plant material as opposed to the sole indication of surface coverage. Therefore, we propose a hybrid model for the retrieval of non-photosynthetic cropland biomass. The workflow included coupling the leaf optical model PROSPECT-PRO with the canopy reflectance model 4SAIL, which allowed us to simulate NPV biomass from carbon-based constituents (CBC) and leaf area index (LAI). PROSAIL-PRO provided a training database for a Gaussian process regression (GPR) algorithm, simulating a wide range of non-photosynthetic vegetation states. Active learning was employed to reduce and optimize the training data set. In addition, we applied spectral dimensionality reduction to condense essential information of non-photosynthetic signals. The resulting NPV-GPR model was successfully validated against soybean field data with normalized root mean square error (nRMSE) of 13.4% and a coefficient of determination (R2) of 0.85. To demonstrate mapping capability, the NPV-GPR model was tested on a PRISMA hyperspectral image acquired over agricultural areas in the North of Munich, Germany. Reliable estimates were mainly achieved over senescent vegetation areas as suggested by model uncertainties. The proposed workflow is the first step towards the quantification of non-photosynthetic cropland biomass as a next-generation product from near-term operational missions, such as CHIME.<\/jats:p>","DOI":"10.3390\/rs13224711","type":"journal-article","created":{"date-parts":[[2021,11,21]],"date-time":"2021-11-21T21:00:50Z","timestamp":1637528450000},"page":"4711","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":40,"title":["Assessing Non-Photosynthetic Cropland Biomass from Spaceborne Hyperspectral Imagery"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0784-7717","authenticated-orcid":false,"given":"Katja","family":"Berger","sequence":"first","affiliation":[{"name":"Department of Geography, Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen (LMU), Luisenstr. 37, 80333 Munich, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7491-0291","authenticated-orcid":false,"given":"Tobias","family":"Hank","sequence":"additional","affiliation":[{"name":"Department of Geography, Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen (LMU), Luisenstr. 37, 80333 Munich, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9055-8563","authenticated-orcid":false,"given":"Andrej","family":"Halabuk","sequence":"additional","affiliation":[{"name":"Institute of Landscape Ecology, Slovak Academy of Sciences, Branch Nitra, 949 01 Nitra, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3188-1448","authenticated-orcid":false,"given":"Juan Pablo","family":"Rivera-Caicedo","sequence":"additional","affiliation":[{"name":"Secretary of Research and Postgraduate, CONACYT-UAN, Tepic 63155, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7180-2356","authenticated-orcid":false,"given":"Matthias","family":"Wocher","sequence":"additional","affiliation":[{"name":"Department of Geography, Ludwig-Maximilians-Universit\u00e4t M\u00fcnchen (LMU), Luisenstr. 37, 80333 Munich, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matej","family":"Mojses","sequence":"additional","affiliation":[{"name":"Institute of Landscape Ecology, Slovak Academy of Sciences, Branch Nitra, 949 01 Nitra, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katarina","family":"Gerh\u00e1tov\u00e1","sequence":"additional","affiliation":[{"name":"Institute of Landscape Ecology, Slovak Academy of Sciences, Branch Nitra, 949 01 Nitra, Slovakia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9725-9956","authenticated-orcid":false,"given":"Giulia","family":"Tagliabue","sequence":"additional","affiliation":[{"name":"Remote Sensing of Environmental Dynamics Lab, University Milano-Bicocca, 20126 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0537-6803","authenticated-orcid":false,"given":"Miguel Morata","family":"Dolz","sequence":"additional","affiliation":[{"name":"Image Processing Laboratory (IPL), Parc Cient\u00edfic, Universitat de Val\u00e8ncia, 46980 Paterna, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9303-4557","authenticated-orcid":false,"given":"Ana Belen Pascual","family":"Venteo","sequence":"additional","affiliation":[{"name":"Image Processing Laboratory (IPL), Parc Cient\u00edfic, Universitat de Val\u00e8ncia, 46980 Paterna, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6313-2081","authenticated-orcid":false,"given":"Jochem","family":"Verrelst","sequence":"additional","affiliation":[{"name":"Image Processing Laboratory (IPL), Parc Cient\u00edfic, Universitat de Val\u00e8ncia, 46980 Paterna, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"743","DOI":"10.1890\/09-0302.1","article-title":"The contribution of brown vegetation to vegetation dynamics","volume":"91","author":"Okin","year":"2010","journal-title":"Ecology"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"928","DOI":"10.1016\/j.rse.2009.01.006","article-title":"Estimating fractional cover of photosynthetic vegetation, non-photosynthetic vegetation and bare soil in the Australian tropical savanna region upscaling the EO-1 Hyperion and MODIS sensors","volume":"113","author":"Guerschman","year":"2009","journal-title":"Remote Sens. 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