PT Journal AU Schepaschenko, D Chave, J Phillips, O Lewis, S Davies, S Réjou-Méchain, M Sist, P Scipal, K Perger, C Herault, B Labrière, N Hofhansl, F Affum-Baffoe, K Aleinikov, A Alonso, A Amani, C Araujo-Murakami, A Armston, J Arroyo, L Ascarrunz, N Azevedo, C Baker, T Bałazy, R Bedeau, C Berry, N Bilous, A Bilous, S Bissiengou, P Blanc, L Bobkova, K Braslavskaya, T Brienen, R Burslem, D Condit, R Cuni-Sanchez, A Danilina, D Del Castillo Torres, D Derroire, G Descroix, L Sotta, E d'Oliveira, M Dresel, C Erwin, T Evdokimenko, M Falck, J Feldpausch, T Foli, E Foster, R Fritz, S Garcia-Abril, A Gornov, A Gornova, M Gothard-Bassébé, E Gourlet-Fleury, S Guedes, M Hamer, K Susanty, F Higuchi, N Coronado, E Hubau, W Hubbell, S Ilstedt, U Ivanov, V Kanashiro, M Karlsson, A Karminov, V Killeen, T Koffi, J Konovalova, M Kraxner, F Krejza, J Krisnawati, H Krivobokov, L Kuznetsov, M Lakyda, I Lakyda, P Licona, J Lucas, R Lukina, N Lussetti, D Malhi, Y Manzanera, J Marimon, B Junior, B Martinez, R Martynenko, O Matsala, M Matyashuk, R Mazzei, L Memiaghe, H Mendoza, C Mendoza, A Moroziuk, O Mukhortova, L Musa, S Nazimova, D Okuda, T Oliveira, L Ontikov, P Osipov, A Pietsch, S Playfair, M Poulsen, J Radchenko, V Rodney, K Rozak, A Ruschel, A Rutishauser, E See, L Shchepashchenko, M Shevchenko, N Shvidenko, A Silveira, M Singh, J Sonké, B Souza, C Stereńczak, K Stonozhenko, L Sullivan, M Szatniewska, J Taedoumg, H Ter Steege, H Tikhonova, E Toledo, M Trefilova, O Valbuena, R Gamarra, L Vasiliev, S Vedrova, E Verhovets, S Vidal, E Vladimirova, N Vleminckx, J Vos, V Vozmitel, F Wanek, W West, T Woell, H Woods, J Wortel, V Yamada, T Nur Hajar, Z Zo-Bi, I TI The Forest Observation System, building a global reference dataset for remote sensing of forest biomass SO Scientific data PY 2019 VL 6 IS 198 DI 10.1038/s41597-019-0196-1 AB Forest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (AGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. AGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. All plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities. ER