BROWSE RESULTS BY CATEGORY
All categories
New stories on change detection and ERS-2 re-entry in HEDAVI
Two new stories are now available in ESA’s HEDAVI (HEritage DAta VIsualisation) tool. HEDAVI visualises Earth observation data from satellites in ESA’s Heritage and Third Party Missions programme, and includes some data from the Copernicus Sentinel satellites.
Petermann Glacier (Greenland), 2010
View the journey of a ice island that calved from Greenland's Petermann Glacier in August 2010.
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.
Trailblazing ERS-2 mission enables climate change applications
As ESA’s ERS-2 satellite approaches Earth’s atmosphere for reentry, it’s time to reflect on the mission’s great achievements in powering climate-related applications.
Space helps monitor Earth’s changing biosphere
Earth’s biosphere is continually changing. Through its pioneering Earth observation missions, ESA is making critical contributions to monitor these changes and their impacts on Earth’s water and carbon cycles.
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.
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).
Interviewing Mirko Albani
ESA’s Heritage Space Programme Manager describes the goals of the programme, some of the challenges involved in preserving and improving 40 years of historical Earth observation data, and his passion for curating this long-term archive.
Satellite data central to ocean monitoring
Over 95% of Earth’s water is found in our oceans, and yet sadly, oceans are under stress from climate change and pollution. Monitoring our oceans is vital for Earth’s survival and satellites are the primary means of long-term and independent observation of our vast ocean bodies and their associated coastal zones.
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.
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.
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.
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.
Mission continuity
Long-term availability of Earth observation data from a given instrument is crucial to many data users and their research—but just how does it work?
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.
Envisat ASAR Global Monitoring L1 [ASA_GM1_1P]
This product has been generated from Level 0 data collected when the instrument was in Global Monitoring Mode. One product covers a full orbit. The product includes slant range to ground range corrections. This strip-line product is the standard for ASAR Global Monitoring Mode. It is processed to approximately 1 km resolution using the SPECAN algorithm. The swath width is approximately 400 km. The ASAR GM L0 full mission data archive has been bulk processed to Level 1 (ASA_GM1_1P) in Envisat format with the IPF-ASAR processor Version 6.03. Spatial Resolution: 1 km ground range x 1 km azimuth.
Envisat ASAR IM Single Look Complex L1 [ASA_IMS_1P]
This data product represents a single-look, complex, slant-range, digital image generated from Level 0 ASAR data collected when the instrument is in Image Mode. Seven possible swaths in HH or VV polarisation are available. The product is primarily intended for use in SAR quality assessment and calibration or applications requiring complex SAR images such as interferometry, and can be used to derive higher level products. The spatial coverage is about 100 km along track per 56 - 100 km across track, and the radiometric resolution is 1 look in azimuth, 1 look in range. The file size is 741 Mbytes. It is worth highlighting that Azimuth pixel spacing depends on Earth-Satellite relative velocity and actual PRF and slant range pixel spacing is given by ASAR sampling frequency (19.208 Mhz). Auxiliary data include: Orbit state vector, Time correlation parameters, Main Processing parameters ADS, Doppler Centroid ADS, Chirp ADS, Antenna Elevation Pattern ADS, Geolocation Grid ADS, SQ ADS. Spatial Resolution: Approximately 8m slant range x approximately 4m azimuth.
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.
Envisat ASAR IM Medium Resolution L1 [ASA_IMM_1P]
This ASAR Medium Resolution strip-line product has been generated from Level 0 data collected when the instrument was in Image Mode. This product has lower resolution but higher radiometric resolution than the ASA_IMP. It is intended to perform applications-oriented analysis on large scale phenomena and multi-temporal imaging. This product provides a continuation of the ERS-SAR Image Mode data. The ASAR IM L0 full mission data archive has been bulk processed to Level 1 (ASA_IMM_1P) in Envisat format with the IPF-ASAR processor Version 6.03. Spatial Resolution: 150 m ground range x 150 m azimuth.
Envisat ASAR IM Precision L1 [ASA_IMP_1P]
This is a multi-look, ground range, digital Precision Image generated from Level 0 data collected when the instrument was in Image Mode (7 possible swaths HH or VV polarisation). The product includes slant range to ground range correction. It is for users wishing to perform applications-oriented analysis and applies to multi-temporal imaging and to derive backscattering coefficients. The stand-alone image is generated using the Range/Doppler algorithm. The processing uses up to date (at time of processing) auxiliary parameters corrected for antenna elevation gain, and range spreading loss. Engineering corrections and relative calibration are applied to compensate for well-understood sources of system variability. Absolute calibration parameters, when available (depending on external calibration activities) are provided in the product annotations. This product provides a continuation of the ERS-SAR_PRI product. Spatial Resolution: 30 m ground range x 30 m azimuth.