This is a RA Geophysical Data Record (GDR) product containing radar range, orbital altitude, wind speed, wave height and water vapour from the ATSR/MWR as well as geophysical corrections. The REAPER (REprocessing of Altimeter Products for ERS) product is generated by applying a similar processing as for Envisat RA-2 on the Level 1b consolidated waveforms using 4 different re-trackers, RA calibration improvement, new precise orbit solution (POD), new ionospheric corrections (NICO09 until 1998 and GIM up to 2003), ECMWF ERA-interim model and updated SSB tables. This product contains two data rates: a low rate of 1Hz and a high rate of 20Hz. Most 1Hz data is also represented at 20Hz, while microwave radiometer (ATSR/MWR) data and the atmospheric and geophysical corrections are only given at 1 Hz. The REAPER GDR (ERS_ALT_2_) is a global product including data over ocean, ice and land. It should be noted that this product differs from the Envisat RA2 in the following ways: The product format; which is NetCDF (more details can be found in the Product Handbook, and not PDS The product is delivered based on orbit acquisition and not per pass (pole-to-pole). This product is extended through Envisat RA-2 data.
The creation of the Fundamental Data Records (FDR4ALT) datasets _$$released in March 2024$$ https://earth.esa.int/eogateway/news/fdr4alt-esa-unveils-new-cutting-edge-ers-envisat-altimeter-and-microwave-radiometer-dataset , 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:
1. _$$Fundamental Data Records for Altimetry$$ https://earth.esa.int/eogateway/catalog/fdr-for-altimetry
2. _$$Fundamental Data Records for Radiometry$$ https://earth.esa.int/eogateway/catalog/fdr-for-radiometry
3. _$$Atmospheric Thematic Data Product$$ https://earth.esa.int/eogateway/catalog/tdp-for-atmosphere
4. _$$Inland Waters Thematic Data Product$$ https://earth.esa.int/eogateway/catalog/tdp-for-inland-water
5. _$$Land Ice Thematic Data Product$$ https://earth.esa.int/eogateway/catalog/tdp-for-land-ice
6. _$$Ocean & Coastal Topography Thematic Data Product$$ https://earth.esa.int/eogateway/catalog/tdp-for-ocean-and-coastal-topography
7. _$$Ocean Waves Thematic Data Product$$ https://earth.esa.int/eogateway/catalog/tdp-for-ocean-waves
8. _$$Sea Ice Thematic Data Product$$ https://earth.esa.int/eogateway/catalog/tdp-for-sea-ice