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- Data (20)
- News (6)
- Missions (1)
- Events (12)
- Tools (1)
- Activities (1)
- Documents (3)
Document - General Reference
Envisat-ASAR-science-and-applications.pdf
This document describes the technical specifications of the Envisat ASAR instrument and its operations and objectives.
Document - Proceedings
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.
Event - Conference
3rd ERS Symposium
The ESA Directorate for Observation of the Earth and its Environment held the 3rd ERS Symposium, in 1997, where many of the results from the ERS-1 and ERS-2 missions were presented and discussed by the scientific community.
Event - Workshop
Applications of the ERS Along Track Scanning Radiometer Workshop 1999
The workshop on ERS mission's Along Track Scanning Radiometer (ATSR) instrument gathered researchers and specialists working on different applications of the mission.
Event - Conference
15 Years of Progress in Radar Altimetry Symposium
A Symposium on "15 Years of Progress in Radar Altimetry" and the annual meeting of the Ocean Surface Topography Science Team, the International Doris Service Workshop and the ARGO Workshop.
Event - Training
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.
Event - Conference
Living Planet Symposium 2019
ESA's Living Planet Symposia are amongst the biggest Earth observation conferences in the world. Scientists present their latest findings on Earth's environment and climate.
Event - Meeting
20th GHRSST Science Team Meeting
The 20th GHRSST International Science Team meeting in 2019 brought together sea surface temperature experts to look at future innovations.
Mission - Heritage Missions
ERS
The ERS programme was composed of two missions, ERS-1 and ERS-2, which together observed the Earth for 20 years, from 1991 to 2011.
Data - Fast Registration with approval (Restrained)
ERS-1/2 ATSR Averaged Surface Temperature [AT1/AT2_AR__2P]
The Averaged Surface Temperature Product (AST) contains averaged geophysical data at two different resolutions, and with respect to two different averaging schemes: measurement data sets at resolutions of 0.5 by 0.5 degrees and 10 by 10 arcmin with respect to a latitude/longitude grid; other data sets contain data averaged over equal area cells of 50 by 50 km and 17 by 17 km aligned with the satellite ground track. Both top-of-atmosphere and surface data sets are provided. The surface temperature data sets provide, for sea cells, nadir and dual view sea surface temperatures, and for land cells, land surface temperature (currently 11 micron BT) and NDVI. Cloud data is also included. No ADS are included in the AST product; auxiliary data is contained within the MDS. The data sets of the AST product are arranged by surface type and resolution. The 3rd reprocessing of ATSR data was performed in 2013; the processing updates that have been put in place and the scientific improvements are outlined in full in the User Summary Note for the Third ERS ATSR Reprocessing.
Data - Data Description
ERS-1/2 ATSR Meteo Product [AT1/AT2_MET_2P]
The data is a fast delivery Meteo product designed for use by meteorological offices, and contains averaged BT and SST at 10 arc minute resolution. The single MDS comprises the fields of MDS#3 (SST record, 10 arc min cell) of the AST product, with the addition of Average Brightness Temperature (ABT) fields (BT/TOA sea record, 10 arc min cell) to make it more self-contained. The 3rd reprocessing of ATSR data was performed in 2013; the processing updates that have been put in place and the scientific improvements are outlined in full in the User Summary Note for the Third ERS ATSR Reprocessing.
Data - Data Description
ERS-1/2 ATSR ARC L2P/L3U [UPA-L2P_GHRSST/L3U_GHRSST]
The L2P product contains full resolution dual-view Sea Surface Temperature (SST) values. These SST use the ARC SST retrieval and cloud screening which differ from the methods used to produce the Gridded Surface Temperature (ATS_NR__2P) products. In addition to SST, the L2P products contain the ATSR Saharan Dust Index (ASDI) and the clear-sky probability estimated by the ARC cloud detection algorithm. The L2P processor also generates L3U products; these are the L2P products averaged onto a regular grid at 0.1 degree resolution (they are therefore similar to the AR / Meteo Envisat-format products). The L2P and L3U products are provided in NetCDF-4 format following GHRSST Data Specifications (GDS) v2. The L2P/L3U archive has been reprocessed with a new processor based upon the ARC SST; the changes are outlined in full in the L2P Reprocessing User Note.
Data - Fast Registration with approval (Restrained)
ERS-1/2 ATSR Gridded Brightness Temperature/Reflectance [AT1/AT2_TOA_1P]
The Gridded Brightness Temperature/Reflectance (GBTR) product contains top of atmosphere (TOA) brightness temperature (BT) values for the infra-red channels and reflectance values for the visible channels. Values for each channel and for the nadir and forward views occupy separate measurement data sets. Additional MDS contain cloud and land/sea flags and confidence flags for each image pixel. The 3rd reprocessing of ATSR data was performed in 2013; the processing updates that have been put in place and the scientific improvements are outlined in full in the User Summary Note for the Third ERS ATSR Reprocessing.
Data - External Data (Restrained)
ERS-1/2 ATSR ARC Level 3 products [AT1/AT2_AVG_3PAARC]
The recommended ATSR Level 3 products for Sea Surface Temperature (SST) applications are the ARC (ATSR Re-processing for Climate) Level 3 products. ARC reprocesses the ATSR multi-mission archive using new cloud detection and SST retrievals to produce a homogenous record of sea surface temperature. The main ARC objective is to reduce regional biases in retrieved SST to less than 0.1 K for all global oceans while creating a very homogenous record with a stability (lack of drift in the observing system and analysis) of 0.05 K per decade. ARC products are available for ATSR-1, ATSR-2 and AATSR. ARC products are provided in netCDF format and contain data for both the skin SST and the SST estimated for depths of 0.2 and 1.0 m (corresponding approximately to drifter and moored buoy depths). The AATSR estimated depth SSTs are adjusted to a local equatorial crossing time of 10:30 (approximately half an hour after observation), to provide continuity with ATSR-1 and ATSR-2 data. The ARC project was led by Chris Merchant (University of Reading, formerly of the University of Edinburgh) and funded by NERC and the UK Government.
Data - Fast Registration with approval (Restrained)
ERS-1/2 ATSR Gridded Surface Temperature [AT1/AT2_NR__2P]
The Gridded Surface Temperature (GST) Product is the Level 2 full resolution geophysical product. The product contains gridded sea-surface temperature images using both nadir and dual view retrieval algorithms. The product includes pixel latitude/longitude positions, X/Y offset and the results of the cloud-clearing/land-flagging. It contains a single measurement data set the content of which is switchable, that is to say, the content of each pixel field will depend on the surface type. Specifically, the contents of the data fields will depend on the setting of the forward and nadir cloud flags and the land flag. The 3rd reprocessing of ATSR data was performed in 2013; the processing updates that have been put in place and the scientific improvements are outlined in full in the User Summary Note for the Third ERS ATSR Reprocessing.
Data - EO Sign In Authentication (Open)
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 - EO Sign In Authentication (Open)
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 - EO Sign In Authentication (Open)
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 - Fast Registration with immediate access (Open)
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 - Data Service Request (Restrained)
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.