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  • Data (15)
  • News (8)
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  • Events (8)
  • Documents (2)
  • Document - Newsletter

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    Earth Online Newsletter - 08 March 2024

    This issue of the Earth Online Newsletter covers a selection of the latest news and events from ESA.

  • News - Data Release news

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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.

  • News - Operational News

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    Temporary interruption to Envisat AATSR dissemination service

    A planned downtime will affect the access to the ftp dissemination server for the Envisat AATSR data during the period 13-15 February 2024.

  • News - Thematic area articles

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    Space data support Earth’s ecosystems

    ESA’s Earth observation (EO) missions are making a critical contribution to monitoring transformations in our planet’s ecosystems, helping track changes in the vegetation, soil, and ocean that affect these systems.

  • News - Thematic area articles

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    Global understanding of Earth's land surfaces greatly boosted by satellite data

    ESA perform land surface monitoring with a range of instruments onboard satellites acquiring optical and radar data. Collections of data from these missions are freely available for research purposes.

  • Event - Training

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    EO Summer School 5

    ESA's series of summer schools, on Monitoring of the Earth System, aims to promote the exploitation of Earth observation data.

  • News - Events and Proceedings

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    Data preservation takes centre stage at Living Planet Symposium

    Against the backdrop of the famed Rhine River, world-class scientists and Earth observation data-users are gathered this week in the historical city of Bonn, at the Living Planet Symposium (LPS).

  • News - Success Stories

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    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.

  • News - Thematic area articles

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    Satellite data boost global understanding of land surface

    Understanding our changing land surface is essential in the study of climate change. Satellites are used to monitor changes to the material that covers Earth’s surface, so-called land cover, such as vegetation and water.

  • Event - Workshop

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    Fringe 2003 Workshop

    The third ESA International Workshop on ERS SAR Interferometry and its first Workshop on ASAR interferometry: Advances in SAR interferometry from ERS and Envisat missions.

  • Event - Workshop

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    Envisat Validation Workshop 2002

    The workshop covered various aspects of validation of the Envisat instruments.

  • Data - Data Description

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    Envisat ASAR AP Co- and Cross-polar L0 [ASA_APC/APH/APV_0P]

    The ASAR Alternating Polarization Mode Level 0 (Co-polar and Cross-polar H and V) products contain time-ordered Annotated Instrument Source Packets (AISPs) corresponding to one of the three possible polarisation combinations: HH & HV, VV & VH and HH & VV, respectively. The echo samples in the AISPs have been compressed to 4 bits/sample using FBAQ. This is a high-rate, narrow swath mode, so data is only acquired for partial orbit segments. There are two co-registered images per acquisition and may be from one of seven different image swaths. The Level 0 product was produced systematically for all data acquired within this mode. Data Size: 56-100 km across track x 100 km along track. There are three AP Mode Level 0 products: ASA_APH_0P: The Cross-polar H Level 0 product corresponds to the polarisation combination HH/HV. ASA_APV_0P: The Cross-polar V Level 0 product corresponds to the polarisation combination VV/VH. ASA_APC_0P: The Co-polar Level 0 product corresponds to the polarisation combination HH/VV= H and H received/V transmit and V received.

  • News - Infographics

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    Envisat - ESA's versatile Earth observation satellite

    Learn more about ESA's Envisat mission - the largest Earth observation satellite ever built - in a new infographic.

  • Data - Fast Registration with immediate access (Open)

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    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.

  • Data - EO Sign In Authentication (Open)

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    ERS-1/2 SAR IM Precision L1 [SAR_IMP_1P]

    The SAR Precision product is a multi-look (speckle-reduced), ground range image acquired in Image Mode. This product type is most applicable to users interested in remote sensing applications, but is also suitable for calibration purposes. The products are calibrated and corrected for the SAR antenna pattern and range-spreading loss. Radar backscatter can be derived from the products for geophysical modelling, but no correction is applied for terrain-induced radiometric effects. The images are not geocoded, and terrain distortion (foreshortening and layover) has not been removed. The numbering sequence relates to the satellite position and therefore differs between Ascending and Descending scenes. Product characteristics: Pixel size: 12.5 m (range - across track) x 12.5 m (azimuth - along track) Scene area: 100 km (range) x at least 102.5 km (azimuth) Scene size: 8000 pixels range x at least 8200 lines (azimuth) Pixel depth: 16 bits unsigned integer Total product volume: 125 MB Projection: Ground-range Number of looks: 3.

  • Data - EO Sign In Authentication (Open)

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    ERS-1/2 SAR IM Single Look Complex L1 [SAR_IMS_1P]

    The SAR SLC product is a single look complex acquired in Image Mode. It is a digital image, with slant range and phase preserved, generated from raw SAR data using up-to-date auxiliary parameters. The products are intended for use in SAR quality assessment, calibration and interferometric applications. A minimum number of corrections and interpolations are performed on the data. Absolute calibration parameters (when available) are provided in the product annotation. Product characteristics: Pixel size: 8 m (range - across track) x 4 m (azimuth - along track – varying slightly depending on acquisition Pulse Repetition Frequency) Scene area: 100 km (range) x at least 102.5 km (azimuth) Scene size: 5000 samples (range) x at least 30000 lines (azimuth) Pixel depth: 32 bits signed integer (16 bits I, 16 bits Q) Total product volume: 575 MB Projection: Slant range- Number of looks: 1.

  • Data - Data Service Request (Restrained)

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    ERS-1/2 SAR IM L0 [SAR_IM__0P]

    This SAR Level 0 product is acquired in Image Mode. The products consist of the SAR telemetry data and are supplied as standard scenes. It also contains all the required auxiliary data necessary for data processing. The product serves two main purposes: For testing ERS SAR processors independently from the HDDR system For users interested in full SAR data processing. Product characteristics: Scene area: 100 km (range - across track) x full segment length (azimuth - along track) Scene size: 5616 samples (range) x full segment length (azimuth) Pixel depth: 10 bits signed integer (5 bits I, 5 bits Q) Projection: Slant range.

  • Data - EO Sign In Authentication (Open)

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    ERS-1/2 SAR IM Medium Resolution L1 [SAR_IMM_1P]

    This ERS Medium Resolution stripline product is generated from the Image Mode Level 0 Product. Stripline image products contain image data for an entire segment, up to a maximum size of 10 minutes per product for IM mode. The processor concatenates together several sub-images called "slices" that were processed separately on a dataset-by-dataset basis in order to form the entire stripline image. The product is processed to an approximately 150 m x 150 m resolution and has a radiometric resolution that is good enough for ice applications. This product has a lower spatial resolution than the SAR_IMP_1P and SAR_IMS_1P products. Product Characteristics: Pixel size: 5 m (ground range – across track) x 75 m (azimuth – along track) Scene area: 100 km (range) x at least 102.5 km Scene Size: 1300 pixels (range) x at least 1350 lines (azimuth) Pixel depth: 16 bits unsigned integer- Total product volume: at least 3.5 MB Projection: Ground-range Number of looks: 8 (azimuth) x 7 (range).

  • Data - EO Sign In Authentication (Open)

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    Envisat ASAR WS Medium Resolution L1 [ASA_WSM_1P]

    The strip-line product has been generated from Level 0 data collected when the instrument was in Wide Swath Mode. The product includes slant range to ground range corrections and covers a continuous area along the imaging swath. It is intended to perform application oriented analysis on large scale phenomena over a wide region and for multi-temporal imaging. This is the standard product for ASAR Wide Swath Mode. The ASAR WS L0 full mission data archive has been bulk processed to Level 1 (ASA_WSM_1P) in Envisat format with the IPF-ASAR processor Version 6.03. Spatial Resolution: 150 m slant range x 150 m azimuth.

  • Data - EO Sign In Authentication (Open)

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    Envisat ASAR AP Medium Resolution L1 [ASA_APM_1P]

    This ASAR Alternating Polarization Medium Resolution Image product has been generated from Level 0 data collected when the instrument was in Alternating Polarisation Mode. The product has lower geometric resolution but higher radiometric resolution than ASA_APP and contains one or two co-registered images corresponding to one of the three polarisation combination sub modes (HH and VV, HH and HV, VV and VH). This product has been processed using the SPECAN algorithm and contains radiometric resolution good enough for ice applications and covers a continuous area along the imaging swath. The ASAR AP L0 full mission data archive has been bulk processed to Level 1 (ASA_APM_1P) in Envisat format with the IPF-ASAR processor Version 6.03. Spatial Resolution: 150 m ground range x 150 m azimuth.