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As you can see from the articles and posters presented on our website EGSIEM enjoyed a high profile at this year’s EGU Assembly in Vienna. As the coordinator I was able to report directly on it in session G4.2 on satellite gravimetry where there was a real interest in the products that the consortium hopes to produce. Not only was there quite a few mentions of EGSIEM in various talks such as in the one from the GRACE PI Byron Tapley, but the few hardcopies of the EGSIEM Newsletter which we were able to bring to the Assembly were rapidly snapped up by interested audience members. Obviously this is good news for the project, it shows that there is a very real need for more timely and combined GRACE products, and was something we suspected during the grant preparation stage, but it is always nice to speak directly to people at events such as EGU and have your suspicions confirmed!

EGSIEM will also be attending the 26th IUGG General Assembly in Prague, ESA’s Third Space for Hydrology Workshop, ESA’s Earth Observation Science 2.0 Workshop, ESA’s Earth Observation for Water Cycle Science Workshop, and the AGU 2015 fall meeting where we will eventually update the community on our first year’s work.

This blog entry is clearly a glimpse into the future of gravity measurements, far beyond EGSIEM, which is maybe also of interest for some readers. Today, and in EGSIEM, measurements of satellites such as those of the GRACE mission are the backbone for our understanding of gravity and mass variations. In the future, new possibilities will emerge on the horizon. One of these is the measurement of the “gravitational redshift” of time and frequency. Due to general relativity, clocks in a stronger gravity field run slower.. In the near future, ultra-precise atomic clocks are expected to be useful sensors for spatial and temporal variations of Earth gravity. Recently, the first long-distance transfer and comparison of optical frequencies generated by Strontium clocks in Braunschweig, Germany, and Paris has been successful. The long-distance frequency transfer to the remote location is done through optical communication fibers. Results and possible applications in geodesy were presented in April at the 2015 Joint Conference of the IEEE International Frequency Control Symposium & European Frequency and Time Forum in Denver, Colorado.

Fill your glass with water, and you'll feel the weight in your hand.

Fill a barrel with water and you'll need a horse to carry it.

Fill an ocean with water and you'll get enough mass to change the path of a satellite.

Back in the 17th century, Newton told us about the law of gravitation. The well-known rule is that mass attracts mass. Because the mass of water is so important on Earth, it modifies gravitational attraction and impacts the orbits of satellites. Every time the GRACE satellites fly over an area, such as the Amazon basin for example, or Greenland, the mass of water below the satellites (or frozen water!) is different, and impacts the orbit differently. By measuring precisely the deviation of the orbit, and applying sophisticated reverse calculations, scientists can determine the quantity of water below the satellite's path. That's why current and future gravity missions represent a very innovative tool to monitor climate and water cycle (draughts, floods, ice melt, and so on).

The EGSIEM project has been featured in the latest issue of the Pan European Networks publication Science and Technology (p. 58-59).

In the article A Warmer World, readers can learn how the the EGSIEM project will utilize Earth Observation data to develop tools for alerting the public to the effects of Global Warming.

Please click on the link below to access the whole issue (new site).

The bottom link will take you directly to the article.

http://www.paneuropeannetworkspublications.com/ST14/files/assets/basic-html/index.html#1

A Warmer World (Link)

How do we ensure the quality of our products?

Within the EGSIEM project, gravity-based products are being developed for various applications. The objective is for our scientific service to provide the best possible time-variable gravity field and to develop other completely new near-realtime products. Obviously the quality of the products needs to be evaluated. This validation will not only allow us to identify outliers but more importantly will also increases users’ confidence in our data products.

How do we know that the product is better than any other product?

The group in Luxembourg has the responsibility for validating the gravity products. Having extensive experience in satellite gravity data processing and applications and in GNSS loading ULux will begin by using GNSS observations to test the quality of the products. Other possibilities for testing the gravity products include using existing models of continental water mass or ocean bottom pressure data, but these will be evaluated at a later date.

The EGSIEM Consortium is pleased to announce the publishing of our very first Newsletter.

The Newsletters will appear quarterly throughout the three year duration of the project and they will give the reader an insight into the products, people & projects within EGSIEM.

We hope you enjoy reading our first issue and we welcome any feedback.

Newsletter No.1 (Link)

 

The European Geosciences Union's General Assembly 2015 is just around the corner, and will give you a chance to meet the EGSIEM scientists in person. Last year, over 12000 scientists from 106 countries participated in the assembly, making it a diverse event where you can keep up with the latest progress in your field, but also have a chance to look over the rim of your tea cup: Besides geodesy, such diverse fields as Biogeosciences, Hydrological Sciences, Seismology, and Solar-Terrestrial Sciences will be represented.

The new service named EGSIEM (European Gravity Service for Improved Emergency Management) will provide an improved forecast and mapping of hydrological extreme events, based on satellite generated gravity field data.

Within the project the German Aerospace Center (DLR) will perform retrospective comparative analyses of GRACE data and other earth observation data from past large flood events, in order to detect spatio-temporal correlation between the occurrence of large flood events and changes in the gravity field of the earth. At the moment test areas are being defined by searching several global earth observation initiatives such as the International Charter 'Space & Major Disasters' for very large flood events.

The findings shall then be integrated into the ZKI workflow to establish an early warning component, which can then be used for early stage satellite programming in case of emerging large scale flood events.

Besides improving the forecast of weather and climate events, EGSIEM will generally improve the usability of gravity field data in Earth and Environmental science and their temporal resolution.

The EGSIEM project started on the first of January 2015 and one of the first deliverables to be agreed upon and reported to the European Union was due at the end of February: a set of processing standards that are obligatory for all Analysis Centers working within the framework of EGSIEM. These earth observation data standards have to be defined carefully, because otherwise the products offered by the different Analysis Centers (Universität Bern, Technische Universität Graz, the GeoForschungsZentrum, the Centre National d’Etudes Spatiales and Université du Luxembourg) cannot be combined easily. The difficulty for the user is the choice of deciding which results from which Analysis Center to use, and what actions to perform for converting spherical harmonics into gridded mass values appropriate for their study. The GPS orbits, contributed by CODE (Center for Orbit Determination in Europe), have to refer to the same reference frame as the GRACE gravity products derived from the different processing centers.

February 6, 2015: The Critical Design Review (CDR) of the GRACE Follow-on (GRACE-FO) mission was successfully passed at Airbus Defense & Space in Friedrichshafen. A  team of NASA experts reviewed the design of the ground, instrument and satellite systems. The Board found no significant issues and therefore the flight hardware is now in full production. The target launch date is August 2017. The novelty of GRACE-FO is the experimental Laser Ranging Interferometer (LRI), the first interspacecraft laser interferometer ever. The LRI is a joint undertaking between NASA and Germany. EGSIEM partners have important roles in the GRACE-FO mission: GFZ Potsdam is responsible for the launch vehicle and for mission operation, provides Laser Retroreflectors (LRR) for both satellites and is strongly involved in the data analysis within the joint US/German Science Data System. For the LRI instrument, AEI Hannover provided the basic design, prototyping and instrument management in Germany.

 

The start of the EGSIEM Project was announced with a number of Press Releases by consortium members.

The Coordinators of EGSIEM (the University of Bern) published an article on the 14th of January 2015.

 

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