Data of the Advanced Very High Resolution Radiometer (AVHRR) onboard of many NOAA- and since 2006 on EUMETSAT MetOp-satellites is the only source to provide long time series based on an almost unchanged sensor of the last 40 years with daily availability and 1.1km spatial resolution. This long period fulfills the requirements of the World Meteorological Organization for a statistical sound analysis to study climate change induced shifts of Essential Climate Variables (ECV). Beside the central NOAA CLASS archive exist many local archives, which are partly not accessible or the data holdings are not well maintained to be used by research teams. A few archives in Europe have data holdings covering Europe on a daily basis but are not homogenized and consolidated. In the frame of ESA’s Long Term Data Preservation (LTDP) program the data holdings of University of Bern (Switzerland), European Space Agency and Dundee Satellite Receiving Station (UK) are combined, redundancy removed and validated to proof readability of the AVHRR LAC level 1b data. In a final step, metafiles and quicklooks are generated to be included in a data container (EO-SIP). The metafiles include some quality indicators to guarantee the usability of the data set. This may help the user to select the needed files for their own investigations. Finally, the homogenized data set was transferred to ESA to keep the unique AVHRR images alive for the next +50 years and make it accessible for all interested parties via ESA web interfaces. The whole process for consolidation of the AVHRR data was in-line with the recommendations of the CEOS Working Group on Information Systems and Services (WGISS) to fulfill the needs for data management and stewardship maturity.
The presentation will give some details about the consolidation process to build one of the largest AVHRR archive in Europe, which are a valuable source to retrieve ECVs. The second part will show some examples of ECVs (snow cover of the European Alps; Lake Surface Water Temperature and Albedo) for a time period of more than 35 years to highlight the value of this exceptional data set. Due to the open and free accessibility of the AVHRR LAC data via ESA interfaces the data set will be also used for projects recently started in the frame of ESA Climate Change Initiative (CCI).

The ESA Fundamental Data Record for ALTimetry (FDR4ALT) project is part of the ESA Long Term Data Preservation Programme (LTDP) aimed at the preservation of ESA’s assets in science data from space, which patently embraces the Earth Observation (EO) data. The ESA LTDP programme funds the data preservation, the data valorization and data accessibility of ESA and Third Party Missions (TPM) EO “Heritage Missions”, starting 5 years after the end of the satellite nominal operations.
Following the successful decades of ERS and Envisat Altimetry mission operations and data exploitation, the FDR4ALT project shall revisit the long-standing series of Altimetry observations (i.e. associated Level 1 and Level 2 processing, data set validation and traceability according to the QA4EO standards, provision of uncertainties, generation of Fundamental Data Record time series and Thematic Data Products, etc.) with the objective of improving the performance of the ESA heritage data sets and their continuity with current (e.g. CryoSat-2, Sentinel-3, Jason) and future missions for multi-disciplinary applications and broader data use.
This paper aims at presenting the status and progress of the ESA FDR4ALT project, issued as an ESA Intention To Tender (ITT) in the 4th quarter of 2018, as well as the objectives of the Fundamental Data Record for ATMOSpheric Composition (FDR4ATMOS) project to be issued in the 1st quarter of 2019, covering generation of FDRs from the atmospheric sensors GOME/ERS-2 and MIPAS, SCIAMACHY on ENVISAT.

The 4th MERIS data reprocessing is in the process to be finalised and the products should be available in the near future. It is focused on the alignment, as far as possible, of the MERIS and Sentinel-3/OLCI data processing chains in order to ensure a continuity of the products derived from these two instruments.
A major evolution of this reprocessing is related to the data formatting: the Envisat data format (.N1) is given up in favour to the Sentinel-3 SAFE format based on a folder of netCDF files including a xml manifest file.
Moreover, following recommendations by the MERIS QWG, a number of algorithm and auxiliary data evolutions have been implemented.
The source of the meteo data included in the L1 and L2 products is now ECMWF Era-Interim.
At level 1,
• The L1 calibration is updated based on a reanalysis of the complete mission in-flight calibration dataset. It includes in particular a revised diffuser ageing methodology accounting also for the ageing of the reference diffuser.
• The geolocation is improved: parallax and orographic corrected latitude, longitude and altitude are given per pixel.
• The a priori surface classification masks (land/sea, tidal areas and in-land-waters) are significantly upgraded and are in line with those used by the OLCI data processing.
At level 2, a large number of algorithms evolutions have also been implemented:
• The computation of the surface pressure over land and inland waters is improved taking into account the per-pixel altitude and an improved relationship of barometric pressure with the altitude.
• The computations of H2O, O2 and O3 transmissions have been revised and the NO2 absorption has been added in the total gaseous atmospheric transmittance;
• The smile correction is performed through the pressure adjustment by using an equivalent Rayleigh optical thickness shift.
• The radiometric land/water reclassification has been revised following upgrades of the a priori masks: (1) Reclassified pixels outside the tidal areas remain in their original branch; (2) The Flood and Dry Fallen masks have been added.
• Cloud screening is improved thanks to the used of NN derived from the ESA Climate Change Initiative (CCI) programme, and enriched with semi-transparent cirrus clouds detection using O2 absorption;
• The Water Vapour retrieval has been upgraded through the use of the 1D-var algorithm;
• Handling of molecular scattering is improved for both Marine and Land processing by the use of accurate pixel elevation, better modelling of the relationship between pressure and elevation, better modelling of the Rayleigh optical thickness (Bodhaine et al., 1999) and improved correction of meteorological variation of atmospheric pressure.
• For the Marine processing, (1) The atmospheric correction over coastal waters is better handled thanks to the improvement of the Bright Pixel Atmospheric Correction (BPAC); (2) New aerosols models (Ahmad et al., 2010) have been implemented in the LUTs that now have been extended to several pressure levels for use over in-land as well as oceanic waters; (3) Vicarious gains in the VIS have been recomputed to account for modified L1 calibration, atmospheric correction upgrades and updated in-situ measurement datasets and Vicarious adjustment in the NIR (relative to one band) is discarded because the new BPAC is more robust to errors in the NIR and spectrally aligns the path reflectance for each pixel; (4) The Kd_490 product (Morel, 2007) has been added; (5) The Case 2 Ocean Colour algorithm has been upgraded taking into account a new bio-optical model derived from NOMAD data set and extended for Case 2 water with 5 components and an atmospheric correction based on the atmosphere model of CoastColour which includes a variable ground pressure.
• For the Land processing, aerosols retrieval over land has been improved with a better modelling of the surface BRDF; the aerosol Angstrom exponent climatology has been updated and a new product is introduced (T442_ALPHA) and a quality index Q as well.
• Uncertainties have been added to ocean and land products.
The presentation will review the evolutions of the 4th MERIS data reprocessing and present a set of validation results.

New orbit solutions for the ERS-1 and ERS-2 satellites are provided as an update to the solutions generated in the framework of the REAPER project (Reprocessing of Altimeter Products for ERS, funded by the European Space Agency - ESA). The new solutions are consistent with the POE-F standards adopted for current altimeter satellites. In addition, the new solutions cover the full mission period for ERS-2, i.e. the period from June 2003 to July 2011 is taken into account as well. The latter results in ERS-1 and ERS-2 orbit solutions that cover, respectively, August 1991 - July 1996 and May 1995 - July 2011. The initial orbit solutions are a combination of two orbit solutions by ESA/ESOC (Germany) and Delft University of Technology (The Netherlands), using a combination of Satellite Laser Tracking (SLR) and altimeter crossover observations, augmented with Precise Range and Range-Rate Equipment (PRARE) tracking observations when available. In a second step, a final combination is generated that includes the DGFI-TUM solution as well which has been kindly made available to the REAPER project to be included in the combination process (in the case of the DGFI solution for ERS-2 the end date is February 2006). The quality of the orbit solutions is assessed by comparing the individual orbit solutions with each other, orbit overlap analysis, fit of tracking and altimeter crossover observations, and sea level records.

SPOT 1-5 satellites have collected more than 25 million images all over the word during the last 30 years from 1986 to 2015 which represents a unique historical dataset.
Spot World Heritage (SWH) is the CNES initiative to preserve and promote this SPOT archive by providing new enhanced products to users.
A first step has begun in 2015 with the start of the repatriation of the SPOT data hosted in the Direct Receiving Stations spread across the world.

The SPOT images are stored as level 0 products under the dedicated GERALD (Generic Exchange for raw Archive Level Data) format. It is a long-term format, totally independent from exchange media, self-contained (it contains all the auxiliary
and ancillary data to elaborate final products towards users) and without loss on information.
The main drawback of the current GERALD archive format is that it is not directly useable: it is a proprietary format with the image data stored in a raw format, and with onboard characteristics. The level 0 data is not “despatialized”.

In order to facilitate the use of SPOT products, three new SWH products have been defined: L1A, L1B and L1C.
L1A product will be the first image product (GeoTIFF) including basic radiometric corrections and preliminary cloud cover estimation;

L1B product will be in segment format and will provide geometric corrections in line with Sentinel-2 L1B product.
L1C product will be the orthorectified product in Top Of Atmosphere reflectance, still in line with Sentinel-2 L1C
product with a specific split in 20km x 20km tiles (sub-tiling of 100 km x 100 km S2 L1C tiles).

SWH processing will take place on CNES High Performance Computing Centre to take advantage of SPOT archive proximity and will use Big Data technologies to manage this volume of data, such as Docker for deployment and Elastic Stack for cataloguing and supervision.

Access will be free and controlled as defined in SWH license agreement.