scholarly journals The impact of the ozone effective temperature on satellite validation using the Dobson spectrophotometer network

2016 ◽  
Author(s):  
M. E. Koukouli ◽  
M. Zara ◽  
C. Lerot ◽  
K. Fragkos ◽  
D. S. Balis ◽  
...  
Keyword(s):  
Effective Temperature ◽  
Scale Validation ◽  
European Space Agency ◽  
Correlation Coefficients ◽  
Global Scale ◽  
Post Process ◽  
Space Agency ◽  
The World ◽  
Effective Temperatures ◽  
The Impact

Abstract. The main aim of the paper is to demonstrate an approach for post-processing of the Dobson spectrophotometers total ozone columns [TOCs] in order to compensate for their known stratospheric effective temperature (Teff) dependency and its resulting effect on the usage of the Dobson TOCs for satellite TOCs validation. The Dobson observations employed are those routinely submitted to the World Ozone and UV Data Centre (WOUDC) of the World Meteorological Organization whereas the effective temperatures have been extracted from two sources: the European Space Agency, ESA, Ozone Climate Change Initiative, Ozone-CCI, GODFIT version 3 (GOME-type Direct FITting) algorithm applied to the GOME2/MetopA, GOME2A, observations as well as the one derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) outputs. Both temperature sources are evaluated utilizing co-located Ozonesonde measurements also retrieved from the WOUDC database. Both GODFIT_v3 and ECMWF Teffs are found to be unbiased against the ozonesonde observations and to agree with high correlation coefficients, especially for latitudes characterized by high seasonal variability in Teff. The validation analysis shows that, when applying the GODFIT_v3 effective temperatures in order to post-process the Dobson TOC, the mean difference between Dobson and GOME2A GODFIT_v3 TOCs moves from 0.63 ± 0.66 to 0.26 ± 0.46 % in the Northern Hemisphere and from 1.25 ± 1.20 to 0.80 ± 0.71 % in the Southern Hemisphere. The existing solar zenith angle dependency of the differences has been smoothed out, with near-zero dependency up to the 60 to 65° bin and the highest deviation decreasing from 2.38 ± 6.6 to 1.37 ± 6.4 % for the 80 to 85° bin. We conclude that the global scale validation of satellite TOCs against collocated Dobson measurements benefits from a post-correction using suitably estimated Teffs.

scholarly journals The impact of the ozone effective temperature on satellite validation using the Dobson spectrophotometer network

2016 ◽  
Vol 9 (5) ◽  
pp. 2055-2065 ◽  
Author(s):  
Maria Elissavet Koukouli ◽  
Marina Zara ◽  
Christophe Lerot ◽  
Konstantinos Fragkos ◽  
Dimitris Balis ◽  
...  
Keyword(s):  
Effective Temperature ◽  
Scale Validation ◽  
European Space Agency ◽  
Correlation Coefficients ◽  
Global Scale ◽  
Post Process ◽  
Space Agency ◽  
The World ◽  
Effective Temperatures ◽  
The Impact

Abstract. The main aim of the paper is to demonstrate an approach for post-processing of the Dobson spectrophotometers' total ozone columns (TOCs) in order to compensate for their known stratospheric effective temperature (Teff) dependency and its resulting effect on the usage of the Dobson TOCs for satellite TOCs' validation. The Dobson observations employed are those routinely submitted to the World Ozone and Ultraviolet Data Centre (WOUDC) of the World Meteorological Organization, whereas the effective temperatures have been extracted from two sources: the European Space Agency, ESA, Ozone Climate Change Initiative, Ozone-CCI, GODFIT version 3 (GOME-type Direct FITting) algorithm applied to the GOME2/MetopA, GOME2A, observations as well as the one derived from the European Centre for Medium-Range Weather Forecasts (ECMWF) outputs. Both temperature sources are evaluated utilizing co-located ozonesonde measurements also retrieved from the WOUDC database. Both GODFIT_v3 and ECMWF Teffs are found to be unbiased against the ozonesonde observations and to agree with high correlation coefficients, especially for latitudes characterized by high seasonal variability in Teff. The validation analysis shows that, when applying the GODFIT_v3 effective temperatures in order to post-process the Dobson TOC, the mean difference between Dobson and GOME2A GODFIT_v3 TOCs moves from 0.63 ± 0.66 to 0.26 ± 0.46 % in the Northern Hemisphere and from 1.25 ± 1.20 to 0.80 ± 0.71 % in the Southern Hemisphere. The existing solar zenith angle dependency of the differences has been smoothed out, with near-zero dependency up to the 60–65° bin and the highest deviation decreasing from 2.38 ± 6.6 to 1.37 ± 6.4 % for the 80–85° bin. We conclude that the global-scale validation of satellite TOCs against collocated Dobson measurements benefits from a post-correction using suitably estimated Teffs.

scholarly journals Six years of total ozone column measurements from SCIAMACHY nadir observations

2009 ◽  
Vol 2 (1) ◽  
pp. 87-98 ◽  
Author(s):  
C. Lerot ◽  
M. Van Roozendael ◽  
J. van Geffen ◽  
J. van Gent ◽  
C. Fayt ◽  
...  
Keyword(s):  
Cross Sections ◽  
Total Ozone ◽  
Large Scale ◽  
European Space Agency ◽  
Data Sets ◽  
Data Set ◽  
Ozone Data ◽  
Space Agency ◽  
German Aerospace ◽  
The Impact

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.

Connectionist Systems and Signal Processing Techniques Applied to the Parameterization of Stellar Spectra

2010 ◽  
pp. 187-203
Author(s):  
Diego Ordóñez ◽  
Carlos Dafonte ◽  
Bernardino Arcay ◽  
Minia Manteiga
Keyword(s):  
Effective Temperature ◽  
Wavelet Transforms ◽  
European Space Agency ◽  
Wavelength Region ◽  
Atmospheric Parameter ◽  
Automated Classification ◽  
Stellar Spectra ◽  
Additional Information ◽  
Space Agency ◽  
The Galaxy

A stellar spectrum is the finger-print identification of a particular star, the result of the radiation transport through its atmosphere. The physical conditions in the stellar atmosphere, its effective temperature, surface gravity, and the presence and abundance of chemical elements explain the observed features in the stellar spectra, such as the shape of the overall continuum and the presence and strength of particular lines and bands. The derivation of the atmospheric stellar parameters from a representative sample of stellar spectra collected by ground-based and spatial telescopes is essential when a realistic view of the Galaxy and its components is to be obtained. In the last decade, extensive astronomical surveys recording information of large portions of the sky have become a reality since the development of robotic or semi-automated telescopes. The Gaia satellite is one of the key missions of the European Space Agency (ESA) and its launch is planned for 2011. Gaia will carry out the so-called Galaxy Census by extracting precise information on the nature of its main constituents, including the spectra of objects (Wilkinson, 2005). Traditional methods for the extraction of the fundamental atmospheric stellar parameters (effective temperature (Teff), gravity (log G), metallicity ([Fe/H]), and abundance of alpha elements [a/Fe], elements integer multiples of the mass of the helium nucleus) are time-consuming and unapproachable for a massive survey involving 1 billion objects (about 1% of the Galaxy constituents) such as Gaia. This work presents the results of the authors’ study and shows the feasibility of an automated extraction of the previously mentioned stellar atmospheric parameters from near infrared spectra in the wavelength region of the Gaia Radial Velocity Spectrograph (RVS). The authors’ approach is based on a technique that has already been applied to problems of the non-linear parameterization of signals: artificial neural networks. It breaks ground in the consideration of transformed domains (Fourier and Wavelet Transforms) during the preprocessing stage of the spectral signals in order to select the frequency resolution that is best suited for each atmospheric parameter. The authors have also progressed in estimating the noise (SNR) that blurs the signal on the basis of its power spectrum and the application of noise-dependant algorithms of parameterization. This study has provided additional information that allows them to progress in the development of hybrid systems devoted to the automated classification of stellar spectra.

The Impact of the Global, Extensible Electronic Health Record

2011 ◽  
pp. 3-13 ◽  
Author(s):  
David W. Forslund ◽  
David G. Kilman
Keyword(s):  
Electronic Health Records ◽  
Negative Impact ◽  
Global Scale ◽  
Global Perspective ◽  
Health Records ◽  
Technological Advances ◽  
The World ◽  
Electronic Health ◽  
The Impact

With the arrival of the “World Wide Web,” we have witnessed a transition toward a truly global perspective with respect to electronic health records. In recent years, much more discussion has focused on the potential for international virtual electronic health records and what is required for them to become a reality in the world today (Kilman & Forslund, 1997). As the Internet becomes more ubiquitous and Web-enabled, we see access to electronic health records using these technologies becoming more commonplace. Even so, these Web-enabled health records still remain technologically isolated from other medical records in the distributed continuum of care; much of the standardization challenge still stands before us. We have witnessed startling technological advances, but we still face considerable obstacles to the goal of having globally standardized electronic health records. In this chapter we describe some of the issues associated with Web-enabled health records, the role of standards in the evolution of Web-enabled health records, and some of the barriers to the development of globally accessible electronic health records. We discuss possible ways to overcome these barriers and the kinds of benefits and opportunities that global health records will help provide. The global scale perspective makes more evident the very real and potentially tragic consequences of prolonged and unnecessary delays in deploying these technologies. Therefore, in an effort to promote a fuller consciousness of health safety, the chapter concludes with a comparative look at the negative impact of impediments in the movement toward global extensible electronic health records.

Spaceborne monitoring of CO2 emissions from large cities and the impact of aerosols

2020 ◽  
Author(s):  
Sander Houweling ◽  
Jochen Landgraf ◽  
Friedemann Reum ◽  
Hein van Heck ◽  
Wei Tao ◽  
...  
Keyword(s):  
Co2 Emissions ◽  
European Space Agency ◽  
Monitoring Network ◽  
Atmospheric Measurements ◽  
Large Cities ◽  
Anthropogenic Co2 ◽  
Space Agency ◽  
Spatial Coverage ◽  
Spaceborne Monitoring ◽  
The Impact

<p>International agreements to reduce CO2 emissions call for an independent mechanism for evaluating the compliance with emission reduction targets. Atmospheric measurements can provide important information in support of this goal. However, to do this globally requires a drastic expansion of the existing monitoring network, using a combination of surface measurements and satellites. CO2 sensing satellites can deliver the required spatial coverage, filling in the gaps that are difficult to cover on ground. However, to reach the accuracy that is required for monitoring CO2 from space is a challenge, and even more so for anthropogenic CO2.</p><p>The European space agency is preparing for the launch of a constellation of satellites for monitoring anthropogenic CO2 within the Copernicus program, starting in 2025. Scientific support studies have been carried out to define this mission in terms of payload and observational requirements. We report on the AeroCarb study, which investigated the impact retrieval errors due to aerosols in CO2 plumes downwind of large cities, and the potential benefit of an onboard aerosol sensor to help mitigate such errors. In this study, CO2 and aerosol plumes have been simulated at high-resolution for the cities of Berlin and Beijing. The impact of aerosol scattering on spaceborne CO2 measurements has been assessed using a combined CO2-aerosol retrieval scheme, with and without the use of an onboard multi-angular spectropolarimeter (MAP) for measuring aerosols. The results have been used to quantify the accuracy at which the CO2 emissions of Berlin and Beijing can be quantified using inverse modelling and the impact of aerosols depending on the chosen satellite payload. </p><p>In this presentation we summarize the outcome of this study, and discuss the implications for the space borne monitoring of anthropogenic CO2 emissions from large cities.</p>

The ExoMars Trace Gas Orbiter – First Martian Year in Orbit

2020 ◽  
Author(s):  
Håkan Svedhem ◽  
Oleg Korablev ◽  
Igor Mitrofanov ◽  
Daniel Rodionov ◽  
Nicholas Thomas ◽  
...  
Keyword(s):  
Surface Science ◽  
Dust Storm ◽  
European Space Agency ◽  
High Sensitivity ◽  
Global Scale ◽  
Trace Gas ◽  
Full Potential ◽  
Water Ice ◽  
Surface Hydrogen ◽  
Space Agency

<p>The Trace Gas Orbiter, TGO, has in March 2020 concluded its first Martian year in its 400km, 74 degrees inclination, science orbit. It has been a highly successful year, starting with the rise, plateau and decay of the major Global Dust Storm in the summer of 2018. This has enabled interesting results to be derived on the water vapour distribution, dynamic behaviour and upward transport as a consequence of the dust storm. The characterisation of the minor species and trace gasses is continuing and a large number of profiles is produced every day. A dedicated search of methane has shown that there is no methane above an altitude of a few km, with an upper limit established at about 20 ppt (2∙10<sup>-11</sup>). The solar occultation technique used by the spectrometers has definitely proven its strength, both for its high sensitivity and for its capability of making high resolution altitude profiles of the atmosphere. Climatological studies have been initiated and will become more important now that a full year has passed, even if the full potential will be visible only after a few Martian years of operation. The FREND instrument has characterised the hydrogen in the shallow sub-surface on a global scale at a spatial resolution much better than previous missions have been able. It has found areas at surprisingly low latitudes with significant amounts of sub-surface hydrogen, most likely in the form of water ice. The CaSSIS camera has made a high number of images over a large variety of targets, including the landing sites of the 2020 ESA and NASA rovers, Oxia Planum and the Jezero Crater. Stereo imaging has enabled topographic information and precise 3-D landscape synthesis.</p><p>This presentation will summarise the highlights of the first Martian year and discuss planned activities for the near and medium term future.</p><p>The ExoMars programme is a joint activity by the European Space Agency (ESA) and ROSCOSMOS, Russia. It consists of the ExoMars 2016 mission, launched 14 March 2016, with the Trace Gas Orbiter, TGO, and the Entry Descent and Landing Demonstrator, EDM, named Schiaparelli, and the ExoMars 2020 mission, to be launched in July/August 2020, carrying a Rover and a surface science platform to the surface of Mars. <strong><br></strong></p>

The science return of the ESA Hera mission to the binary asteroid Didymos

2020 ◽  
Author(s):  
Patrick Michel ◽  
Michael Kueppers ◽  
Keyword(s):  
Solar System ◽  
European Space Agency ◽  
Direct Determination ◽  
Hypervelocity Impact ◽  
The European Union ◽  
Long Term Effects ◽  
Impact Speed ◽  
Asteroid Impact ◽  
Space Agency ◽  
The Impact

<p>The Hera mission has been approved for development and launch in the new ESA Space Safety Programme by the ESA Council at Ministerial Level, Space19+, in November 2019. Hera will both offer a high science return and contribute to the first deflection test of an asteroid, in the framework of the international NASA- and ESA-supported Asteroid Impact and Deflection Assessment (AIDA) collaboration.</p> <p>The impact of the NASA DART (Doube Asteroid Redirection Test) spacecraft on the natural satellite of Didymos in October 2022 will change its orbital period around Didymos. As Didymos is an eclipsing binary, and close to the Earth on this date, the change can be detected by Earth-based observers. ESA’s Hera spacecraft will rendezvous Didymos four years after the impact. Hera’s instruments will perform the measurements necessary to understand the effect of the DART impact on Didymos’ secondary, in particular its mass, its internal structure, the direct determination of the momentum transfer and the detailed characterization of the crater left by DART. This new knowledge will also provide unique information on many current issues in asteroid science.</p> <p>From small asteroid internal and surface structures, through rubble-pile evolution, impact cratering physics, to the long-term effects of space weathering in the inner Solar System, Hera will have a major impact on many fields. For instance, collisions play a fundamental role in our Solar System history, from planet formation by collisional accretion to cratering of solid surfaces and asteroid family formation by collisional disruption. The fully documented hypervelocity impact experiment provided by DART and Hera will feed collisional models with information obtained at actual asteroid scale and for an impact speed (~6 km/s) that is close to the average impact speed between asteroids in the main belt. Moreover, Hera will perform the first rendezvous with an asteroid binary, characterize the smallest object ever visited (165 m in diameter) and provide the first direct measurement of an asteroid interior. Additionally, studies using Hera data will in turn affect our understanding of the asteroid population as a whole. The scientific legacy of the Hera mission will extend far beyond the core aims of planetary defense.</p> <p>Acknowledgment: The authors acknowledge funding support from ESA and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870377 (project NEO-MAPP), from the European Space Agency and from the French space agency CNES.</p>

scholarly journals Impact of student exclusion (including from the SPE) on their digitisation behaviour in social media

2020 ◽  
Vol 11 (1) ◽  
pp. 203-224
Author(s):  
Marcin Prościak ◽  
Beata Prościak
Keyword(s):  
Social Media ◽  
Social Networking Sites ◽  
Global Scale ◽  
Special Educational Needs ◽  
The Social ◽  
The Family ◽  
The World ◽  
Digital Exclusion ◽  
The Impact ◽  
The Relationship

Aim. The aim of this thesis is to present the impact of students exclusion (including SPEs) on their virtual behaviour in social media. Students with no special educational needs and those with SEN were taken into account. The relationship between exclusion of SPE and digitisation exclusion will be indicated . In addition, social exclusion in the family area was included. Methods: The analysis was based on statistical methods, such as: range, standard deviation, variance. Surveys were used. They were conducted on the Internet through the Facebook social portal on a national and global scale. Results: Respondents from around the world feel more excluded by the SPE than respondents in Poland. In contrast, respondents from the SPE use fewer social networking sites than in groups of computer players, both in Poland and worldwide. Conclusions: In Poland, SPE is not a barrier to communication with peers for most respondents, unlike global respondents. Respondents from the SPE spend less time on social portals because it absorbs their time devoted to learning, which can be an indicator of digital exclusion. Cognitive value: The originality of the research is to focus on introducing the global and Polish scale of the problem excluding students from SPE from the social media, which was calculated by the author’s method based on the indicator digital exclusion.

scholarly journals The Global Water Body Layer from TanDEM-X Interferometric SAR Data

2021 ◽  
Vol 13 (24) ◽  
pp. 5069
Author(s):  
Jose-Luis Bueso-Bello ◽  
Michele Martone ◽  
Carolina González ◽  
Francescopaolo Sica ◽  
Paolo Valdo ◽  
...  
Keyword(s):  
Water Body ◽  
European Space Agency ◽  
Water Layer ◽  
Global Scale ◽  
Data Set ◽  
Primary Input ◽  
Water Detection ◽  
Space Agency ◽  
Digital Elevation ◽  
Global Water

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.

scholarly journals On the Impact Monitoring of Near-Earth Objects: Mathematical Tools, Algorithms, and Challenges for the Future

Universe ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 103
Author(s):  
Giacomo Tommei
Keyword(s):  
European Space Agency ◽  
Historical Evolution ◽  
Planetary Protection ◽  
Impact Monitoring ◽  
The Earth ◽  
Space Agency ◽  
The Future ◽  
Operational Systems ◽  
The Impact ◽  
Near Earth Objects

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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