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- Data (15)
- News (8)
- Missions (1)
- Events (5)
- Documents (2)
Document - Newsletter
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
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
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
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
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
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
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
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
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
Envisat Validation Workshop 2002
The workshop covered various aspects of validation of the Envisat instruments.
Data - Data Description
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
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 - Data Description
GRACE-A and GRACE-B Level 1B, Level 1B combined and Level 2 Data Products
Level-1A Data Products are the result of a non-destructive processing applied to the Level-0 data at NASA/JPL. The sensor calibration factors are applied in order to convert the binary encoded measurements to engineering units. Where necessary, time tag integer second ambiguity is resolved and data are time tagged to the respective satellite receiver clock time. Editing and quality control flags are added, and the data is reformatted for further processing. The Level-1A data are reversible to Level-0, except for the bad data packets. This level also includes the ancillary data products needed for processing to the next data level. The Level-1B Data Products are the result of a possibly destructive, or irreversible, processing applied to both the Level-1A and Level-0 data at NASA/JPL. The data are correctly time-tagged, and data sample rate is reduced from the higher rates of the previous levels. Collectively, the processing from Level-0 to Level-1B is called the Level-1 Processing. This level also includes the ancillary data products generated during this processing, and the additional data needed for further processing. The Level-2 data products include the static and time-variable (monthly) gravity field and related data products derived from the application of Level-2 processing at GFZ, UTCSR and JPL to the previous level data products. This level also includes the ancillary data products such as GFZ's Level-1B short-term atmosphere and ocean de-aliasing product (AOD1B) generated during this processing. GRACE-A and GRACE-B Level-1B Data Product: Satellite clock solution [GA-OG-1B-CLKDAT, GB-OG-1B-CLKDAT, GRACE CLKDAT]: Offset of the satellite receiver clock relative to GPS time, obtained by linear fit to raw on-board clock offset estimates GPS flight data [GA-OG-1B-GPSDAT, GB-OG-1B-GPSDAT, GRACE GPSDAT]: Preprocessed and calibrated GPS code and phase tracking data edited and decimated from instrument high-rate (10 s (code) or 1 s (phase)) to low-rate (10 s) samples for science use (1 file per day, level-1 format) Accelerometer Housekeeping data [GA-OG-1B-ACCHKP, GB-OG-1B-ACCHKP, GRACE ACCHKP]: Accelerometer proof-mass bias voltages, capacitive sensor outputs, instrument control unit (ICU) and sensor unit (SU) temperatures, reference voltages, primary and secondary power supply voltages (1 file per day, level-1 format) Accelerometer data [GA-OG-1B-ACCDAT, GB-OG-1B-ACCDAT, GRACE ACCDAT]: Preprocessed and calibrated Level-1B accelerometer data edited and decimated from instrument high-rate (0.1 s) to low-rate (1s) samples for science use (1 file per day, level-1 format) Intermediate clock solution [GA-OG-1B-INTCLK, GB-OG-1B-INTCLK, GRACE INTCLK]: derived with GIPSY POD software (300 s sample rate) (1 file per day, GIPSY format) Instrument processing unit (IPU) Housekeeping data [GA-OG-1B-IPUHKP, GB-OG-1B-IPUHKP, GRACE IPUHKP]: edited and decimated from high-rate (TBD s) to low-rate (TBD s) samples for science use (1 file per day, level-1 format) Spacecraft Mass Housekeeping data [GA-OG-1B-MASDAT, GB-OG-1B-MASDAT, GRACE MASDAT]: Level 1B Data as a function of time GPS navigation solution data [GA-OG-1B-NAVSOL, GB-OG-1B-NAVSOL, GRACE NAVSOL]: edited and decimated from instrument high-rate (60 s) to low-rate (30 s) samples for science use (1 file per day, level-1 format) OBDH time mapping to GPS time Housekeeping data [GA-OG-1B-OBDHTM, GB-OG-1B-OBDHTM, GRACE OBDHTM]: On-board data handling (OBDH) time mapping data (OBDH time to receiver time Star camera data [GA-OG-1B-SCAATT, GB-OG-1B-SCAATT, GRACE SCAATT]: Preprocessed and calibrated star camera quaternion data edited and decimated from instrument high-rate (1 s) to low-rate (5 s) samples for science use (1 file per day, level-1 format) Thruster activation Housekeeping data [GA-OG-1B-THRDAT, GB-OG-1B-THRDAT, GRACE THRDAT]: GN2 thruster data used for attitude (10 mN) and orbit (40 mN) control GN2 tank temperature and pressure Housekeeping data [GA-OG-1B-TNKDAT, GB-OG-1B-TNKDAT, GRACE TNKDAT]: GN2 tank temperature and pressure data Oscillator frequency data [GA-OG-1B-USODAT, GB-OG-1B-USODAT, GRACE USODAT]: derived from POD product GRACE-A and GRACE-B Combined Level-1B Data Product Preprocessed and calibrated k-band ranging data [GA-OG-1B-KBRDAT, GB-OG-1B-KBRDAT, GRACE KBRDAT]: range, range-rate and range-acceleration data edited and decimated from instrument high-rate (0.1 s) to low-rate (5 s) samples for science use (1 file per day, level-1 format) Atmosphere and Ocean De-aliasing Product [GA-OG-1B-ATMOCN, GB-OG-1B-ATMOCN, GRACE ATMOCN]: GRACE Atmosphere and Ocean De-aliasing Product. GRACE Level-2 Data Product: GAC [GA-OG-_2-GAC, GB-OG-_2-GAC, GRACE GAC]: Combination of non-tidal atmosphere and ocean spherical harmonic coefficients provided as average over certain time span (same as corresponding GSM product) based on level-1 AOD1B product (1file per time span, level-2 format) GCM [GA-OG-_2-GCM, GB-OG-_2-GCM, GRACE GCM]: Spherical harmonic coefficients and standard deviations of the long-term static gravity field estimated by combination of GRACE satellite instrument data and other information for a dedicated time span (multiple years) and spatial resolution (1 file per time span, level-2 format) GAB [GA-OG-_2-GAB, GB-OG-_2-GAB, GRACE GAB]: Non-tidal ocean spherical harmonic coefficients provided as average over certain time span (same as corresponding GSM product) based on level-1 AOD1B product (1file per time span, level-2 format) GAD [GA-OG-_2-GAD, GB-OG-_2-GAD, GRACE GAD]: bottom pressure product - combination of surface pressure and ocean (over the oceans, and zero over land). Spherical harmonic coefficients provided as average over certain time span (same as corresponding GSM product) based on level-1 AOD1B product (1file per time span, level-2 format) GSM [GA-OG-_2-GSM, GB-OG-_2-GSM, GRACE GSM]: Spherical harmonic coefficients and standard deviations of the static gravity field estimated from GRACE satellite instrument data only for a dedicated time span (e.g. weekly, monthly, multiple years) and spatial resolution (1 file per time span, level-2 format).
Data - EO Sign In Authentication (Open)
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)
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)
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)
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)
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)
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.