{"ob_id":40641,"computationComponent":[{"ob_id":40640,"uuid":"361d0f25744840e5bfec5838e2787ace","title":"JRC-TOC FAPAR Computation","abstract":"Look Up Table (LUT) of bidirectional reflectance factors (BRF) representing the AVHRR\r\nNOAA like data are created using the physically-based semi-discrete model of Gobron\r\net al. (1997) to represent the spectral and directional reflectance of horizontally homogeneous plant canopies, as well as to compute the values of FAPAR in each of them.\r\nThe sampling of the vegetation parameters and angular values were chosen to cover a\r\nwide range of environmental conditions. These simulations constitute the basic information used to optimise the formulae. The sampling selected to generate the LUT has\r\nbeen chosen so as to generate a robust global FAPAR algorithm.\r\nOnce this LUT was created, the design of the algorithm consisted in defining the mathematical combination of spectral bands which will best account for the variations of\r\nthe variable of interest (here, FAPAR) on the basis of (simulated) measurements, while\r\nminimising the effect of perturbing factors such as angular effects.\r\nIn the case of bare soil simulations, the Hapke modified soil model of Pinty et al. (1989)\r\nis used with a fixed hot-spot parameter equal to 0.2 and an asymmetry factor equal to\r\n-0.1. The soil data required to specify the lower boundary condition in this model were\r\ntaken from Price (1995). The value of single albedo, for each spectral bands, have been\r\ninverted to obtain the same albedo value as the lambertian assumption is made.","keywords":"","inputDescription":null,"outputDescription":null,"softwareReference":null,"identifier_set":[]}],"acquisitionComponent":[{"ob_id":1667,"independentInstrument":[],"instrumentplatformpair_set":[{"ob_id":689,"platform":"https://catalogue.ceda.ac.uk/api/v2/platforms/1664/?format=json","instrument":"https://catalogue.ceda.ac.uk/api/v2/instruments/1665/?format=json","relatedTo":{"ob_id":1667,"uuid":"4c43f22544cd42f9bb50a7cca0f34dc3","short_code":"acq"}}]},{"ob_id":1681,"independentInstrument":[],"instrumentplatformpair_set":[{"ob_id":4730,"platform":"https://catalogue.ceda.ac.uk/api/v2/platforms/1679/?format=json","instrument":"https://catalogue.ceda.ac.uk/api/v2/instruments/1665/?format=json","relatedTo":{"ob_id":1681,"uuid":"810deaaa6e464bf090d402c88cc584a2","short_code":"acq"}}]},{"ob_id":1695,"independentInstrument":[],"instrumentplatformpair_set":[{"ob_id":4734,"platform":"https://catalogue.ceda.ac.uk/api/v2/platforms/1693/?format=json","instrument":"https://catalogue.ceda.ac.uk/api/v2/instruments/1665/?format=json","relatedTo":{"ob_id":1695,"uuid":"5388228bda17496eabd2b9566d296d58","short_code":"acq"}}]},{"ob_id":1811,"independentInstrument":[],"instrumentplatformpair_set":[{"ob_id":709,"platform":"https://catalogue.ceda.ac.uk/api/v2/platforms/1809/?format=json","instrument":"https://catalogue.ceda.ac.uk/api/v2/instruments/1802/?format=json","relatedTo":{"ob_id":1811,"uuid":"15390f2f1f4e4b70bb05335ac7d8ea87","short_code":"acq"}}]},{"ob_id":1826,"independentInstrument":[],"instrumentplatformpair_set":[{"ob_id":711,"platform":"https://catalogue.ceda.ac.uk/api/v2/platforms/1824/?format=json","instrument":"https://catalogue.ceda.ac.uk/api/v2/instruments/1817/?format=json","relatedTo":{"ob_id":1826,"uuid":"a4e2d6b37bea4e4e87b48d731fce6e35","short_code":"acq"}}]}],"identifier_set":[],"responsiblepartyinfo_set":["https://catalogue.ceda.ac.uk/api/v2/rpis/197735/?format=json"]}