earth online
  • All Categories (18)
  • Data (9)
  • News (2)
  • Events (4)
  • Tools (1)
  • Documents (2)
  • News - Success Stories

    prompt photo

    10 years of Envisat data help to illuminate ocean processes

    A decade after Envisat beamed its final image to the planet, the pioneering ESA mission is continuing to foster improved understanding of Earth’s systems.

  • Event - Workshop

    prompt photo

    SEASAR 2006

    ESA organised it's first SAR oceanography workshop, SEASAR 2006, entitled "Advances in SAR Oceanography from Envisat and ERS missions"

  • Event - Training

    prompt photo

    2nd Advanced Training Course on Ocean Remote Sensing 2009

    This advanced training course focused on ocean remote sensing theory and applications.

  • Tools - Apps

    prompt photo

    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.

  • News - Data Release news

    prompt photo

    ESA's (A)SAR dissemination service enhanced with Envisat ASAR MR L1 data

    With integration of four additional Envisat ASAR Level 1 collections, ESA is now providing access to the complete Envisat and ERS (A)SAR imagery data archive via the ESA (A)SAR Online Dissemination service.

  • Data - Data Service Request (Restrained)

    prompt photo

    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.

  • Event - Workshop

    prompt photo

    SEASAR 2012

    The European Space Agency and the Norwegian Space Centre jointly organised the fourth SAR oceanography workshop, 'SEASAR 2012', entitled 'Advances in SAR Oceanography'.

  • Data - Fast Registration with immediate access (Open)

    prompt photo

    Envisat ASAR WM Ocean Wave Spectra L2 [ASA_WVW_2P]

    The ASAR Wave Mode product is created by inverting the cross-spectra which is computed from inter-look processing of the SLC wave imagettes in order to derive the directional ocean product ocean wave spectra. Auxiliary ADSs included with the product remains the same as for the ASAR Wave Mode Cross-Spectra product. The output follows the format of the Envisat ASAR Level 1B Wave Mode Imagette Cross-Spectra (ASA_WVS_1P) product. This is done in order to be compatible with the ground segment products of Envisat ASAR. This product provides a continuation of the ERS-SAR wave mode data. Output: Wavelength range from 20 to 1000 m in 24 logarithmic steps.

  • Data - Fast Registration with immediate access (Open)

    prompt photo

    Envisat ASAR Wave Imagette Cross Spectra L1 [ASA_WVS_1P]

    The ASAR Wave product is extracted from the combined SLC and Cross Spectra product, ASA_WVI_1P, which is generated from data collected when the instrument was in Wave Mode using the Cross Spectra methodology. The product is meant for Meteo users. The spatial coverage is up to 20 spectra acquired every 100 km, with a minimum coverage of 5km x 5km. The file size has a maximum of 0.2 Mbytes. Auxiliary data include Orbit state vector, Time correlation parameters, Wave Processing parameters ADS, Wave Geolocation ADS, SQ ADS. The product provides a continuation of the ERS-SAR wave mode data. Output: Wavelength range from 20 to 1000 m in 24 logarithmic steps.

  • Data - EO Sign In Authentication (Open)

    prompt photo

    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.

  • Data - Fast Registration with immediate access (Open)

    prompt photo

    Envisat ASAR Wave SLC and Cross-Spectra Imagettes L1 [ASA_WVI_1P]

    This is the basic Level 1B ASAR Wave Mode product, including up to 400 single-look, complex, slant range, imagettes generated from Level 0 data and up to 400 imagette power spectra computed using the cross-spectra methodology. The auxiliary parameters used are the most up-to-date at the time of processing. A minimum number of corrections and interpolations are performed in order to allow the end-user maximum freedom to derive higher level products. Complex output data is retained to avoid loss of information. Absolute calibration parameters, when available (depending on external calibration activities), are provided in the product annotations. Imagette power spectrum is equivalent to the ERS UWA (Near Real Time) product with revisited algorithm (cross-spectra) taking into account the higher quality of the SLC imagette. Note that starting from an SLC imagette, the generation of an ERS UWA-type product might be ensured by a simple look detection and summation. This product provides a continuation of the ERS-SAR wave mode data. Imagette Spatial Resolution: 20 m ground range x 20 m azimuth. Cross Spectra Output: Wavelength range from 20 to 1000 m in 24 logarithmic steps.

  • Data - EO Sign In Authentication (Open)

    prompt photo

    Envisat ASAR AP Single-Look Complex L1 [ASA_APS_1P]

    This product is a complex, slant-range, digital image generated from Level 0 data collected when the instrument is in Alternating Polarisation mode. (7 possible swaths). It contains two CO-registered images corresponding to one of the three polarisation combination submodes (HH and VV, HH and HV, VV and VH). In addition, the product uses the Range Doppler algorithm and the most up to date processing parameters available at the time of processing. It can be used to derive higher level products for SAR image quality assessment, calibration and interferometric applications, if allowed by the instrument acquisition. A minimum number of corrections and interpolations are performed on the data in order to allow the end-user maximum freedom to derive higher level products. Complex output data is retained to avoid loss of information. Absolute calibration parameters are available depending on external calibration activities and are provided in the product annotations. Spatial Resolution: Approximately 8m slant range x approximately 4m azimuth.

  • Data - Data Service Request (Restrained)

    prompt photo

    Envisat ASAR WS L0 [ASA_WS__0P]

    The WS Mode Level 0 product consists of time-ordered AISPs collected while the instrument was is in Wide Swath Mode. The echo samples in the AISPs have been compressed to 4 bits per sample using FBAQ. This is a high-rate, wide swath (ScanSAR) mode so data is only acquired for partial orbit segments and is composed from five image swaths (SS1 to SS5). The Level 0 product is produced systematically for all data acquired within this mode. The objective of this product is to offer Level 0 data for possible image processing on another processing site. It includes mandatory information for SAR processing. Data Size: 400 km across track x 400 km along track.

  • Data - EO Sign In Authentication (Open)

    prompt photo

    Envisat ASAR AP Precision L1 [ASA_APP_1P]

    This ASAR Alternating Polarisation Mode Precision product is generated from Level 0 data collected when the instrument is in Alternating Polarisation Mode (7 possible swaths). The product contains two CO-registered images corresponding to one of the three polarisation combination submodes (HH and VV, HH and HV, VV and VH). This is a stand-alone multi-look, ground range, narrow swath digital image generated using the SPECAN algorithm and the most up to date auxiliary information available at the time of processing. Engineering corrections and relative calibration (antenna elevation gain, range spreading loss) are applied to compensate for well-understood sources of system variability. Generation of this product uses a technique to allow half the looks of an image to be acquired in horizontal polarisation and the other half in vertical polarisation and processed to 30-m resolution (with the exception of IS1). Absolute calibration parameters are available depending on external calibration activities and are provided in the product annotations. Spatial Resolution: 30 m ground range x 30 m azimuth.

  • Data - Data Service Request (Restrained)

    prompt photo

    Envisat ASAR IM L0 [ASA_IM__0P]

    The ASAR Image Mode source packets Level 0 data product offers Level 0 data for possible images processing on an other processing site. It includes some mandatory information for SAR processing. The Image Mode Level 0 product consists of time-ordered Annotated Instrument Source Packets (AISPs) collected by the instrument in Image Mode. The echo samples contained in the AISPs are compressed to 4 bits/sample using Flexible Block Adaptive Quantisation (FBAQ). This is a high-rate, narrow swath mode so data is only acquired for partial orbit segments and may be from one of seven possible image swaths. The Level 0 product is produced systematically for all data acquired within this mode. This product provides a continuation of the ERS-SAR_RAW product.

  • Event - Training

    prompt photo

    Advanced Training Course on Ocean Remote Sensing 2006

    The objective of the course was to provide first-hand information on a broad range of ocean research topics including key principles of SAR, Radar Altimetry, Ocean Colour and Sea Surface Temperature measurements, processing algorithms, data products and their use in oceanographic applications.

  • Document - General Reference

    prompt photo

    Envisat-ASAR-science-and-applications.pdf

    This document describes the technical specifications of the Envisat ASAR instrument and its operations and objectives.

  • Document - Proceedings

    prompt photo

    SEASAR-2012-sessions-summaries-seed-questions-recommendations.pdf

    This document gathers together the sessions summaries with seed questions discussion and recommendations of the SEASAR 2012 workshop.