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  • FDR4ALT - ESA unveils new cutting-edge ERS/Envisat Altimeter and Microwave Radiometer Datasets

    The European Space Agency (ESA) has developed a comprehensive suite of innovative Earth system data records as part of the Fundamental Data Records for Altimetry project - FDR4ALT.

  • 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.

  • ERS-1/2 Radar Altimeter REAPER Geophysical Data Record - GDR [ERS_ALT_2]

    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 1 Hz and a high rate of 20 Hz. Most 1 Hz data is also represented at 20 Hz, 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.

  • ERS-1/2 Radar Altimeter REAPER Sensor Geophysical Data Record - SGDR [ERS_ALT_2S]

    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 1 Hz and a high rate of 20 Hz. Most 1 Hz data is also represented at 20 Hz, 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.

  • ERS-1/2 Radar Altimeter REAPER METEO Product - [ERS_ALT_2M]

    This is a RA Meteo product containing only the 1 Hz parameters for altimeter (surface range, satellite altitude, wind speed and significant wave height at nadir) and ATSR/MWR data (brightness temperature at 23.8 GHz and 36.5 GHz, water vapour content, liquid water content) used to correct altimeter measurements. It also contains the full geophysical corrections. This product corresponds to a subset of the REAPER GDR product (ERS_ALT_2_). 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 only the low rate of 1 Hz data. The REAPER Meteo (ERS_ALT_2M) 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.

  • ERS PRARE Precise Orbit Product (ERS.ORB.POD/ERS.ORB/PRC)

    The precise orbit results from a data reduction process in which all available tracking data (Single-Lens Reflex, radar altimeter crossovers, PRARE range and Doppler data) and most accurate correction, transformation and dynamical models are taken into account and in which high level numerical procedures are applied. These orbits are "optimal" achievable representations of the real orbital motion under the circumstances of tracking situation and the "state of the art" model situation. The precise orbit product for the ERS satellites are the satellite ephemeris (position and velocity vector) including time tag, given in a well-defined reference frame, together with the nominal satellite attitude information and a radial orbit correction. Several orbit solutions are currently distributed: A new set of ORB POD (Precise Orbit Determination - REAPER v2) computed with the most updated model standards for the complete ERS-1 and ERS-2 mission. A previous set of ORB POD (REAPER v1) data already available on the ESA dissemination site since 2014, covering the ERS-1 full mission and the ERS-2 mission up to July 2003. ORB PRC which is the original Precise Orbit dataset computed during the ERS mission operations for ERS-1 and ERS-2. In the new POD dataset (REAPER v2) for the ERS-1 and ERS-2 missions, two different orbit solutions are provided together with the combined solution to be used for processing of the radar altimeter measurements and the determination of geodetic/geophysical products: those computed by DEOS (Delft Institute of Earth Observation and Space Systems), and those generated by ESOC (European Space Operations Centre) using different software (GEODYN and NAPEOS respectively). Careful evaluation of the various solutions of REAPER v2 has shown that the DEOS solution for both ERS-1 and ERS-2 has the best performance and is recommended to be used as reference. See the ERS Orbit Validation Report. For the previous version of the POD data set (REAPER v1), with ERS-2 mission data only up to 2003, three different orbit solutions together with the combined solution are available. These precise orbits for ERS-1 and ERS-2 have been computed at DEOS, ESOC, and GFZ (Deutschen GeoForschungsZentrums) using different software and different altimeter databases. Combined solutions have been created using three individual solutions for each satellite. All orbits were derived using consistent models in the same LPOD2005 terrestrial reference frame. These new orbit solutions show notable improvement with respect to DGME04 orbits (Scharroo and Visser, 1998). Thus, RMS crossover differences of new orbits improved by 4-9 mm. Careful evaluation of the various solutions has shown that the combined solution for both ERS-1 and ERS-2 has the best performance. All POD orbit files (REAPER v1/v2) are available in SP3c format.

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 14 Apr 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 07 Apr 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 28 Apr 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 12 May 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 05 May 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 21 Apr 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 01 Sep 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 09 Jun 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 23 Jun 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 19 May 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 05 Jul 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 08 Jul 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 30 Jun 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report

  • ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report 02 Jun 2002

    ERS-2 AMI-SAR/AMI-Scatterometer Weekly Report