Dataset
QA4ECV DHR-FAPAR level 3 (1982-2006)
Status: Completed
Online Status: ONLINE
Publication State: Working
Publication Date:
Download Stats: last 12 months
Dataset Size: 1.2K Files | 121GB
Abstract
Directional Hemispherical Reflectance (DHR) - Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) products derived from daily spectral measurements acquired by Advanced Very High Resolution Radiometer (AVHRR) onboard a series of National Oceanic and Atmospheric Administration (NOAA) platforms. This work is done in the framework of the Quality Assurance For Essential Climate Variable (QA4ECV) project. The input data are the surface reflectance provided by the Land Long Term Data Record (LTDR) project.
These data are provided as time composite products of 10 days and monthly time periods at 0.05 degree resolution.
Citable as: Kharbouche, S.; Muller, J.-P. (9999): QA4ECV DHR-FAPAR level 3 (1982-2006). Centre for Environmental Data Analysis, date of citation. https://catalogue.ceda.ac.uk/uuid/c1091e99ca2d41fc846ec9bd71b4d09b/
Abbreviation: Not defined
Keywords: FAPAR
Details
| Previous Info: |
No news update for this record
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| Previously used record identifiers: |
No related previous identifiers.
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| Access rules: |
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence(s): http://creativecommons.org/licenses/by/4.0/ When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record. |
| Data lineage: |
Data are provided by the QA4ECV project for archival with CEDA. Data are in NetCDF format. |
| Data Quality: |
Data as provided by the QA4ECV project, archived at CEDA
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| File Format: |
These data are gzipped netCDF products.
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Related Documents
| User guide |
| Deliverable report |
| QA4ECV FAPAR ATBD |
| QA4ECV Land user guide. |
Process overview
This dataset was generated by a combination of instruments deployed on platforms
and computations as detailed below.
Instrument/Platform pairings
| Advanced Very High Resolution Radiometer (AVHRR) | Deployed on: NOAA-7 |
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: NOAA-7 |
Instrument/Platform pairings
| Advanced Very High Resolution Radiometer (AVHRR) | Deployed on: NOAA-9 |
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: NOAA-9 |
Instrument/Platform pairings
| Advanced Very High Resolution Radiometer (AVHRR) | Deployed on: NOAA-11 |
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: NOAA-11 |
Instrument/Platform pairings
| Advanced Very High Resolution Radiometer 2 (AVHRR/2) | Deployed on: NOAA-14 |
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: NOAA-14 |
Instrument/Platform pairings
| Advanced Very High Resolution Radiometer 3 (AVHRR/3) | Deployed on: NOAA-16 |
Mobile platform operations
| Mobile Platform Operation 1 | Mobile Platform Operation for: NOAA-16 |
Computation Element: 1
| Title | JRC-TOC FAPAR Computation |
| Abstract | Look Up Table (LUT) of bidirectional reflectance factors (BRF) representing the AVHRR NOAA like data are created using the physically-based semi-discrete model of Gobron et 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. The sampling of the vegetation parameters and angular values were chosen to cover a wide range of environmental conditions. These simulations constitute the basic information used to optimise the formulae. The sampling selected to generate the LUT has been chosen so as to generate a robust global FAPAR algorithm. Once 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 the variable of interest (here, FAPAR) on the basis of (simulated) measurements, while minimising the effect of perturbing factors such as angular effects. In the case of bare soil simulations, the Hapke modified soil model of Pinty et al. (1989) is used with a fixed hot-spot parameter equal to 0.2 and an asymmetry factor equal to -0.1. The soil data required to specify the lower boundary condition in this model were taken from Price (1995). The value of single albedo, for each spectral bands, have been inverted to obtain the same albedo value as the lambertian assumption is made. |
| Input Description | None |
| Output Description | None |
| Software Reference | None |
| Output Description | None |
| Output Description | None |
| Output Description | None |
| Output Description | None |
| Output Description | None |
No variables found.
Coverage
Temporal Range
Start time:
1982-01-01T00:00:00
End time:
2006-12-31T23:59:59
Geographic Extent
90.0000° |
||
-180.0000° |
180.0000° |
|
-90.0000° |
Related parties