News - Data Release news

Updated Precise Orbit data (POD) for the full ERS-1 and ERS-2 mission available

The Precise Orbit files (ERS.ORB.POD) for the entire ERS-1 and ERS-2 mission periods have been reprocessed with up-to-date standards.

News - Thematic area articles

Transforming space data into climate action

ESA’s Earth observation activities are playing a key role in the revitalised global drive to combat climate change.

Document - General Reference

Taking-the-Measure-of-Earth-Fifteen-Years-of-Progress-in-Radar-Altimetry.pdf

This article is extracted from ESA Bulletin Nr. 128.

Data - EO Sign In Authentication (Open)

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.

Document - Proceedings

PolInSAR-2007-Proceedings-of-the-3rd-International-Workshop-on-Science-and-Applications-of-SAR-Polarimetry-and-Polarimetric-Interferometry.pdf

Proceedings of PolInSAR 2007 held in Frascati, Italy on from 22-26 January 2007.

Data - EO Sign In Authentication (Open)

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.

Data - EO Sign In Authentication (Open)

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.

Document - General Reference

Monitoring-Marine-Life-from-Space-Envisat-Experience-in-Chile.pdf

This article was published in the ESA Bulletin Nr. 126 and describes the use of satellite data for monitoring the environmental conditions of coastal waters and the health of southern oceans.

News - Spotlight on EO community

Introducing Mirko Albani

In this short introduction, ESA's Heritage Missions Programme Manager describes what he likes most about ESA's long term archive of satellite mission data and his role in the programme.

News - Success Stories

How Envisat helped to shape global understanding of Earth’s systems

Twenty years have passed since a ground-breaking European spacecraft designed to deliver unprecedented insight into the planet’s changing environment was lofted into orbit.

Document - General Reference

Highlights-of-the-ERS-Envisat-Symposium.pdf

This article was published in the ESA Bulletin Nr. 105 and providesdetails on the achievements of the ESA's Earth ObservationProgramme following the Gothenburg's symposium.

Tools - Apps

Heritage Missions app for iOS

Download the Heritage Missions application to discover what the missions were about, how it worked and what the elements of the space and ground segment that make these missions unique.

Tools - Apps

Heritage Missions app for Android

Download the Heritage Missions application to discover what the missions were about, how it worked and what the elements of the space and ground segment that make these missions unique.

Document - General Reference

GLOBCOVER-The-most-detailed-portrait-of-Earth.pdf

This is an article extracted from the ESA Bulletin Nr. 136.

News - Data Release news

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.

Document - General Reference

Europe's ENVISAT Environment Satellite

Document - General Reference

ESA-Bulletin-Nr-106-Envisat-Special-Issue.pdf

This issue of the ESA Bulletin is fully dedicated to the ENVISAT mission.

News - General News

ESA's improved Earth system data records: what is in store for the future?

Fundamental Data Records (FDRs) are instrumental in advancing our understanding of Earth systems and for addressing societal challenges effectively. These long-term records contain uncertainty-quantified, calibrated and geo-located multi-instrument/multi-platform satellite sensor data spanning several decades to support climate-related applications.

Document - Proceedings

ERS-Envisat Symposium

Data - Fast Registration with immediate access (Open)

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.