BROWSE RESULTS BY CATEGORY
DATA
Fundamental Data Records for Radiometry [MWR_FDR___]
This dataset is a Fundamental Data Record (FDR) resulting from the ESA FDR4ALT project. The Fundamental Data Record for Radiometry V1 products contain intercalibrated Top of the Atmosphere brightness temperatures at 23.8 and 36.5 GHz. The collection covers data for the ERS-1, ERS-2 and Envisat missions, and is built upon a new processing of Level 0 data, incorporating numerous improvements in terms of algorithms, flagging procedures, and corrections. Compared to existing datasets, the Radiometry FDR demonstrates notable improvements in several aspects: New solutions for instrumental effects (ERS Reflector loss, Skyhorn, and Sidelobe corrections) Native sampling rate of 7Hz with enhanced coverage The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Fundamental Data Records for Altimetry [ALT_FDR___]
This dataset is a Fundamental Data Record (FDR) resulting from the ESA FDR4ALT project. The Fundamental Data Record for Altimetry V1 products contain Level 0 and Level 1 altimeter-related parameters including calibrated radar waveforms and supplementary instrumental parameters describing the altimeter operating status and configuration through the satellite lifetime. The data record consists of data for the ERS-1, ERS-2 and Envisat missions for the period ranging from 1991 to 2012, and bases on the Level 1 data obtained from previous ERS REAPER and ENVISAT V3.0 reprocessing efforts incorporating new algorithms, flags, and corrections to enhance the accuracy and reliability of the data. For many aspects, the Altimetry FDR product has improved compared to the existing individual mission datasets: New neural-network waveform classification, surface type classification, distance to shoreline and surface flag based on GSHHG Instrumental calibration information directly available in the product Improved Orbit solutions Correction of REAPER drawbacks (i.e., time jumps and negative waveforms) The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Land Ice Thematic Data Product [ALT_TDP_LI]
This is the Land Ice Thematic Data Product (TDP) V1 resulting from the ESA FDR4ALT project and containing estimates of ice sheet surface elevation and associated uncertainties. The collection covers data for three different missions: ERS-1, ERS-2 and Envisat, and based on Level 1 data coming from previous reprocessing (ERS REAPER and the Envisat V3.0) but taking into account the improvements made at Level 0/Level 1 in the frame of FDR4ALT (ALT FDR). The Land Ice TDP focuses specifically on the ice sheets of Greenland and Antarctica, providing these data in different files. For many aspects, the Land Ice Level 2 and Level 2+ processing is very innovative: Improved relocation approach correcting for topographic effects within the beam footprint to identify the Point of Closest Approach Homogeneous timeseries of surface elevation measurements at regular along-track reference nodes. The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Sea Ice Thematic Data Product [ALT_TDP_SI]
This is the Sea Ice Thematic Data Product (TDP) V1 resulting from the ESA FDR4ALT project and containing the sea ice related geophysical parameters, along with associated uncertainties: snow depth, radar and sea-ice freeboard, sea ice thickness and concentration. The collection covers data for the ERS-1, ERS-2 and Envisat missions, and bases on Level 1 data coming from previous reprocessing (ERS REAPER and the Envisat V3.0) but taking into account the improvements made at Level 0/Level 1 in the frame of FDR4ALT (ALT FDR). The Sea Ice TDP provides data from the northern or southern hemisphere in two files corresponding to the Arctic and Antarctic regions respectively for the winter periods only, i.e., October to June for the Arctic, and May to November for the Antarctic. For many aspects, the Sea Ice TDP is very innovative: First time series of sea-ice thickness estimates for ERS Homogeneous calibration, allowing the first Arctic radar freeboard time series from ERS-1 (1991) to CryoSat-2 (2021) Uncertainties estimated along-track with a bottom-up approach based on dominant sources ERS pulse blurring error corrected using literature procedure [Peacock, 2004] The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Inland Waters Thematic Data Product [ALT_TDP_IW]
This is the Inland Waters Thematic Data Product (TDP) V1 resulting from the ESA FDR4ALT project and containing improved Water Surface Height (WSH) data record from the ERS-1, ERS-2 and Envisat missions estimated using the ICE1 retracking range for its better performance on the hydro targets. The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Ocean and Coastal Topography Thematic Data Product [ALT_TDP_OC]
This is the Ocean and Coastal Topography Thematic Data Product (TDP) V1 resulting from the ESA FDR4ALT project and containing improved sea surface height anomaly data records both at 1 Hz and 20 Hz resolution to address climate and/or coastal areas studies. The collection covers data for the ERS-1, ERS-2 and Envisat missions. Note that a dedicated processing to coastal zones has been applied for coastal distances below 200 km. Compared to existing datasets, the Ocean and Coastal Topography TDP demonstrates notable improvements in several aspects: Up-to-date orbit and geophysical corrections applied Adaptive retracker for Envisat The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Ocean Waves Thematic Data Product [ALT_TDP_WA]
This is the Ocean Waves Thematic Data Product (TDP) V1 resulting from the ESA FDR4ALT project and containing Significant Wave Height estimates for the ERS-1, ERS-2 and Envisat missions. Compared to existing datasets, the Ocean Waves TDP demonstrates notable improvements in several aspects: Great improvements for Envisat due to noise reduction from Adaptive retracker and High-Frequency Adjustment (HFA) All variables are given at 5 Hz The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Atmospheric Thematic Data Product [MWR_TDPATM]
This is the Atmospheric Thematic Data Product (TDP) V1 resulting from the ESA FDR4ALT project and containing Total Column Water Vapour (TCWV), Cloud Liquid Water Path (LWP), Atmospheric Attenuation of the altimeter backscattering coefficient at Ku-band (AttKu), and Wet Tropospheric Correction (WTC), retrieved from observations of the Microwave Radiometer (MWR) instruments flown on-board the ERS-1, and ERS-2, and Envisat satellites. Compared to existing datasets, the Atmospheric TDP demonstrates notable improvements in several aspects: Improved temporal coverage, especially for ERS-2 Improved L0 -> 1 processing Two different corrections are provided based on a neural network retrieval or on a 1D-VAR approach The FDR4ALT products are available in NetCDF format. Free standard tools for reading NetCDF data can be used. Information for expert altimetry users is also available in a dedicated NetCDF group within the products. Please consult the FDR4ALT Product User Guide before using the data. The FDR4ALT datasets represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are strongly encouraged to make use of these datasets for optimal results.
Envisat RA-2 Geophysical Data Record - GDR [RA2_GDR__2P]
This is a RA-2 Geophysical Data Record (GDR) Full Mission Reprocessing (FMR) V3 product containing radar range and orbital altitude, wind speed, wave height, water vapour from the MWR and geophysical corrections. This FMR follows the first Envisat Altimetry reprocessing Version (V2.1) completed in 2012. The GDR and S-GDR data products were reprocessed for all cycles from 6 to 113 (May 2002 to April 2012) into a homogeneous standard in NetCDF format (close to Sentinel-3). For many aspects, the V3.0 reprocessed data are better than the previous dataset: In terms of available and valid data, the coverage is better, notably thanks to a better availability of MWR data at the beginning of the mission In terms of performance at cross-overs, the quality is improved: the annual signal and average of Mean SSH is decreased, as well as the standard deviation The new MWR characteristics were shown to improve largely the global quality of data. As well as the new tide model, the new MSS and the new orbit standard The Global and regional Mean Sea Level trend is very weakly impacted though the effort was put, this time, on the mesoscale restitution, rather than long term drift, as during V2.1 reprocessing. Please consult the Envisat RA-2/MWR Product Quality Readme file PDF before using the data. The creation of the Fundamental Data Records (FDR4ALT) datasets released in March 2024, represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are therefore strongly encouraged to make use of these new datasets for optimal results. The records are aimed at different user communities and include the following datasets: Fundamental Data Records for Altimetry Fundamental Data Records for Radiometry Atmospheric Thematic Data Product Inland Waters Thematic Data Product Land Ice Thematic Data Product Ocean & Coastal Topography Thematic Data Product Ocean Waves Thematic Data Product Sea Ice Thematic Data Product
Envisat RA-2 Sensor and Geophysical Data Record - SGDR [RA2_MWS__2P]
This is a RA-2 Sensor and Geophysical Data Record (SGDR) Full Mission Reprocessing (FMR) V3 product. This FMR follows the first Envisat Altimetry reprocessing Version (V2.1) completed in 2012. The GDR and S-GDR data products were reprocessed for all cycles from 6 to 113 (May 2002 to April 2012) into a homogeneous standard in NetCDF format (close to Sentinel-3). The Sensor Data Record (SGDR) Product from RA-2/MWR includes the data in the GDR product (RA-2 geophysical data, MWR data) and also RA-2 averaged waveforms (18Hz) and RA-2 individual waveforms (1800Hz). This product is a continuation of ERS RA data. This data product has a coverage of 1 pass and pole to pole, a spatial sampling of about 390 m along track and a size of 31 to 40 MB, depending on presence of individual waveforms. The radiometric accuracy is 0.2 dB and auxiliary data include: Orbit state vectors (DORIS, FOS), RA2 and MWR characterisation data, Platform attitude, Gain calibration, USO frequency, ECMWF data, time relation, leap second, Ionospheric corrections, geoid, mean sea surface, slope data, and tide model (ocean, earth, loading, pole). Please consult the Envisat RA-2/MWR Product Quality Readme file before using the data. The creation of the Fundamental Data Records (FDR4ALT) datasets released in March 2024, represent the new reference data for the ERS/Envisat altimetry missions, superseding any previous mission data. Users are therefore strongly encouraged to make use of these new datasets for optimal results. The records are aimed at different user communities and include the following datasets: Fundamental Data Records for Altimetry Fundamental Data Records for Radiometry Atmospheric Thematic Data Product Inland Waters Thematic Data Product Land Ice Thematic Data Product Ocean & Coastal Topography Thematic Data Product Ocean Waves Thematic Data Product Sea Ice Thematic Data Product