scholarly journals Assimilation of reprocessed ERS scatterometer data into ECMWF weather analysis on the Mediterranean Sea

2005 ◽  
Vol 2 ◽  
pp. 327-329 ◽  
Author(s):  
R. Crapolicchio ◽  
P. Lecomte ◽  
H. Hersbach

Abstract. Since the launch of ERS-1 in 1991 and ERS-2 in 1995, carrying a C-band Scatterometer, a data set of more than thirteen years of backscattered signal from the Earth surface is available for exploitation. With its global coverage, day or night and all-weather operation, ERS Scatterometer data offer unique opportunity for long-term studies and research. To fulfill the needs of the scientific community, the European Space Agency (ESA) has developed the project: Advanced Scatterometer Processing System (ASPS). Main scope of the project is to provide with state-of-the-art algorithm, high quality and homogenous Scatterometer measurements (sigma nought) of the Earth surface and high quality wind field over the Oceans by re-processing the entire ERS mission. Additional scope is to provide on experimental basis scientific products in high resolution tailored for the emerging Scatterometer application on Ice and Land. The ASPS project is now in a pre-operational phase and the scope of the paper is to give to the scientific community an overview of the ASPS data and show the assimilation of the data into the ECMWF weather analysis system. ASPS data hopefully will help the scientific community to better understand and monitor the Earth's climate changes and to protect our environment.

2019 ◽  
Vol 9 (1) ◽  
pp. 111-126
Author(s):  
A. F. Purkhauser ◽  
J. A. Koch ◽  
R. Pail

Abstract The GRACE mission has demonstrated a tremendous potential for observing mass changes in the Earth system from space for climate research and the observation of climate change. Future mission should on the one hand extend the already existing time series and also provide higher spatial and temporal resolution that is required to fulfil all needs placed on a future mission. To analyse the applicability of such a Next Generation Gravity Mission (NGGM) concept regarding hydrological applications, two GRACE-FO-type pairs in Bender formation are analysed. The numerical closed loop simulations with a realistic noise assumption are based on the short arc approach and make use of the Wiese approach, enabling a self-de-aliasing of high-frequency atmospheric and oceanic signals, and a NRT approach for a short latency. Numerical simulations for future gravity mission concepts are based on geophysical models, representing the time-variable gravity field. First tests regarding the usability of the hydrology component contained in the Earth System Model (ESM) by the European Space Agency (ESA) for the analysis regarding a possible flood monitoring and detection showed a clear signal in a third of the analysed flood cases. Our analysis of selected cases found that detection of floods was clearly possible with the reconstructed AOHIS/HIS signal in 20% of the tested examples, while in 40% of the cases a peak was visible but not clearly recognisable.


2021 ◽  
Vol 217 (1) ◽  
Author(s):  
Valeria Mangano ◽  
Melinda Dósa ◽  
Markus Fränz ◽  
Anna Milillo ◽  
Joana S. Oliveira ◽  
...  

AbstractThe dual spacecraft mission BepiColombo is the first joint mission between the European Space Agency (ESA) and the Japanese Aerospace Exploration Agency (JAXA) to explore the planet Mercury. BepiColombo was launched from Kourou (French Guiana) on October 20th, 2018, in its packed configuration including two spacecraft, a transfer module, and a sunshield. BepiColombo cruise trajectory is a long journey into the inner heliosphere, and it includes one flyby of the Earth (in April 2020), two of Venus (in October 2020 and August 2021), and six of Mercury (starting from 2021), before orbit insertion in December 2025. A big part of the mission instruments will be fully operational during the mission cruise phase, allowing unprecedented investigation of the different environments that will encounter during the 7-years long cruise. The present paper reviews all the planetary flybys and some interesting cruise configurations. Additional scientific research that will emerge in the coming years is also discussed, including the instruments that can contribute.


2009 ◽  
Vol 2 (1) ◽  
pp. 87-98 ◽  
Author(s):  
C. Lerot ◽  
M. Van Roozendael ◽  
J. van Geffen ◽  
J. van Gent ◽  
C. Fayt ◽  
...  

Abstract. Total O3 columns have been retrieved from six years of SCIAMACHY nadir UV radiance measurements using SDOAS, an adaptation of the GDOAS algorithm previously developed at BIRA-IASB for the GOME instrument. GDOAS and SDOAS have been implemented by the German Aerospace Center (DLR) in the version 4 of the GOME Data Processor (GDP) and in version 3 of the SCIAMACHY Ground Processor (SGP), respectively. The processors are being run at the DLR processing centre on behalf of the European Space Agency (ESA). We first focus on the description of the SDOAS algorithm with particular attention to the impact of uncertainties on the reference O3 absorption cross-sections. Second, the resulting SCIAMACHY total ozone data set is globally evaluated through large-scale comparisons with results from GOME and OMI as well as with ground-based correlative measurements. The various total ozone data sets are found to agree within 2% on average. However, a negative trend of 0.2–0.4%/year has been identified in the SCIAMACHY O3 columns; this probably originates from instrumental degradation effects that have not yet been fully characterized.


2018 ◽  
Vol 616 ◽  
pp. A13 ◽  
Author(s):  
◽  
F. Spoto ◽  
P. Tanga ◽  
F. Mignard ◽  
J. Berthier ◽  
...  

Context. The Gaia spacecraft of the European Space Agency (ESA) has been securing observations of solar system objects (SSOs) since the beginning of its operations. Data Release 2 (DR2) contains the observations of a selected sample of 14,099 SSOs. These asteroids have been already identified and have been numbered by the Minor Planet Center repository. Positions are provided for each Gaia observation at CCD level. As additional information, complementary to astrometry, the apparent brightness of SSOs in the unfiltered G band is also provided for selected observations. Aims. We explain the processing of SSO data, and describe the criteria we used to select the sample published in Gaia DR2. We then explore the data set to assess its quality. Methods. To exploit the main data product for the solar system in Gaia DR2, which is the epoch astrometry of asteroids, it is necessary to take into account the unusual properties of the uncertainty, as the position information is nearly one-dimensional. When this aspect is handled appropriately, an orbit fit can be obtained with post-fit residuals that are overall consistent with the a-priori error model that was used to define individual values of the astrometric uncertainty. The role of both random and systematic errors is described. The distribution of residuals allowed us to identify possible contaminants in the data set (such as stars). Photometry in the G band was compared to computed values from reference asteroid shapes and to the flux registered at the corresponding epochs by the red and blue photometers (RP and BP). Results. The overall astrometric performance is close to the expectations, with an optimal range of brightness G ~ 12 − 17. In this range, the typical transit-level accuracy is well below 1 mas. For fainter asteroids, the growing photon noise deteriorates the performance. Asteroids brighter than G ~ 12 are affected by a lower performance of the processing of their signals. The dramatic improvement brought by Gaia DR2 astrometry of SSOs is demonstrated by comparisons to the archive data and by preliminary tests on the detection of subtle non-gravitational effects.


2009 ◽  
Vol 4 (3) ◽  
pp. 4-16 ◽  
Author(s):  
Sergio Albani ◽  
David Giaretta

ESA-ESRIN, the European Space Agency Centre for Earth Observation (EO), is the largest European EO data provider and operates as the reference European centre for EO payload data exploitation. EO Space Missions provide global coverage of the Earth across both space and time generating on a routine continuous basis huge amounts of data (from a variety of sensors) that need to be acquired, processed, elaborated, appraised and archived by dedicated systems. Long-term Preservation of these data and of the ability to discover, access and process them is a fundamental issue and a major challenge at programmatic, technological and operational levels.Moreover these data are essential for scientists needing broad series of data covering long time periods and from many sources. They are used for many types of investigations including ones of international importance such as the study of the Global Change and the Global Monitoring for Environment and Security (GMES) Program. Therefore it is of primary importance not only to guarantee easy accessibility of historical data but also to ensure users are able to understand and use them; in fact data interpretation can be even more complicated given the fact that scientists may not have (or may not have access to) the right knowledge to interpret these data correctly.To satisfy these requirements, the European Space Agency (ESA), in addition to other internal initiatives, is participating in several EU-funded projects such as CASPAR (Cultural, Artistic, and Scientific knowledge for Preservation, Access and Retrieval), which is building a framework to support the end-to-end preservation lifecycle for digital information, based on the OAIS reference model, with a strong focus on the preservation of the knowledge associated with data.In the CASPAR Project ESA plays the role of both user and infrastructure provider for one of the scientific testbeds, putting into effect dedicated scenarios with the aim of validating the CASPAR solutions in the Earth Science domain. The other testbeds are in the domains of Cultural Heritage and of Contemporary Performing Arts; together they provide a severe test of preservation tools and techniques.In the context of the current ESA overall strategies carried out in collaboration with European EO data owners/providers, entities and institutions which have the objective of guaranteeing long-term preservation of EO data and knowledge, this paper will focus on the ESA participation and contribution to the CASPAR Project, describing in detail the implementation of the ESA scientific testbed.


2021 ◽  
Author(s):  
Wouter Dorigo ◽  
Irene Himmelbauer ◽  
Daniel Aberer ◽  
Lukas Schremmer ◽  
Ivana Petrakovic ◽  
...  

Abstract. In 2009, the International Soil Moisture Network (ISMN) was initiated as a community effort, funded by the European Space Agency, to serve as a centralised data hosting facility for globally available in situ soil moisture measurements (Dorigo et al., 2011a, b). The ISMN brings together in situ soil moisture measurements collected and freely shared by a multitude of organisations, harmonizes them in terms of units and sampling rates, applies advanced quality control, and stores them in a database. Users can freely retrieve the data from this database through an online web portal (https://ismn.earth). Meanwhile, the ISMN has evolved into the primary in situ soil moisture reference database worldwide, as evidenced by more than 3000 active users and over 1000 scientific publications referencing the data sets provided by the network. As of December 2020, the ISMN now contains data of 65 networks and 2678 stations located all over the globe, with a time period spanning from 1952 to present.The number of networks and stations covered by the ISMN is still growing and many of the data sets contained in the database continue to be updated. The main scope of this paper is to inform readers about the evolution of the ISMN over the past decade,including a description of network and data set updates and quality control procedures. A comprehensive review of existing literature making use of ISMN data is also provided in order to identify current limitations in functionality and data usage, and to shape priorities for the next decade of operations of this unique community-based data repository.


Author(s):  
B. Sánchez-Cano ◽  
O. Witasse ◽  
M. Herraiz ◽  
S. M. Radicella ◽  
J. Bauer ◽  
...  

Abstract. Since 2005 the Mars Advanced Radar and Ionospheric Sounding experiment (MARSIS) aboard Mars Express has acquired a unique data set on the ionosphere of Mars made up of ionospheric soundings taken by the instrument working in its Active Ionospheric Sounding (AIS) mode. These soundings play a role similar to those of modern Terrestrial digisondes in the analysis of our planet ionosphere and have allowed us to dramatically improve our knowledge about the Martian ionosphere. This paper describes this kind of data, which are available from the public Planetary Science Archive, and introduces the MAISDAT tool developed by the European Space Agency to analyze and derive the vertical profile of electron density. Comparisons with radio-occultation profiles obtained from Mars Express Radio Science instrument are performed to validate the procedure used in this study.


2021 ◽  
Vol 13 (24) ◽  
pp. 5069
Author(s):  
Jose-Luis Bueso-Bello ◽  
Michele Martone ◽  
Carolina González ◽  
Francescopaolo Sica ◽  
Paolo Valdo ◽  
...  

The interferometric synthetic aperture radar (InSAR) data set, acquired by the TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) mission (TDM), represents a unique data source to derive geo-information products at a global scale. The complete Earth’s landmasses have been surveyed at least twice during the mission bistatic operation, which started at the end of 2010. Examples of the delivered global products are the TanDEM-X digital elevation model (DEM) (at a final independent posting of 12 m × 12 m) or the TanDEM-X global Forest/Non-Forest (FNF) map. The need for a reliable water product from TanDEM-X data was dictated by the limited accuracy and difficulty of use of the TDX Water Indication Mask (WAM), delivered as by-product of the global DEM, which jeopardizes its use for scientific applications, as well. Similarly as it has been done for the generation of the FNF map; in this work, we utilize the global data set of TanDEM-X quicklook images at 50 m × 50 m resolution, acquired between 2011 and 2016, to derive a new global water body layer (WBL), covering a range from −60∘ to +90∘ latitudes. The bistatic interferometric coherence is used as the primary input feature for performing water detection. We classify water surfaces in single TanDEM-X images, by considering the system’s geometric configuration and exploiting a watershed-based segmentation algorithm. Subsequently, single overlapping acquisitions are mosaicked together in a two-step logically weighting process to derive the global TDM WBL product, which comprises a binary averaged water/non-water layer as well as a permanent/temporary water indication layer. The accuracy of the new TDM WBL has been assessed over Europe, through a comparison with the Copernicus water and wetness layer, provided by the European Space Agency (ESA), at a 20 m × 20 m resolution. The F-score ranges from 83%, when considering all geocells (of 1∘ latitudes × 1∘ longitudes) over Europe, up to 93%, when considering only the geocells with a water content higher than 1%. At global scale, the quality of the product has been evaluated, by intercomparison, with other existing global water maps, resulting in an overall agreement that often exceeds 85% (F-score) when the content in the geocell is higher than 1%. The global TDM WBL presented in this study will be made available to the scientific community for free download and usage.


Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 103
Author(s):  
Giacomo Tommei

The Impact Monitoring (IM) of Near-Earth Objects (NEOs) is a young field of research, considering that 22 years ago precise algorithms to compute an impact probability with the Earth did not exist. On the other hand, the year 2020 just passed saw the increase of IM operational systems: in addition to the two historical systems, CLOMON2 (University of Pisa/SpaceDyS) and Sentry (JPL/NASA), the European Space Agency (ESA) started its own system AstOD. Moreover, in the last five years three systems for the detection of imminent impactors (small asteroidal objects detected a few days before the possible impact with the Earth) have been developed: SCOUT (at JPL/NASA), NEORANGER (at University of Helsinki) and NEOScan (at University of Pisa/SpaceDyS). The IM science, in addition to being useful for the planetary protection, is a very fascinating field of research because it involves astronomy, physics, mathematics and computer science. In this paper I am going to review the mathematical tools and algorithms of the IM science, highlighting the historical evolution and the challenges to be faced in the future.


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