Institute of Space Research
Institute of Space Research
Dubinin E.,Max Planck Institute for Solar System Research |
Fraenz M.,Max Planck Institute for Solar System Research |
Patzold M.,Rheinisches Institute fuer Umweltforschung |
Andrews D.,Swedish Institute of Space Physics |
And 3 more authors.
Planetary and Space Science | Year: 2017
We present multi-instrument observations of the effects of solar irradiance on the upper Martian ionosphere and escape fluxes based on Mars Express measurements obtained over almost 12 years. It is shown that the variations in the upper ionosphere caused by solar irradiance lead to significant changes in the trans-terminator fluxes of low-energy ions and total ion losses through the tail. The observed dependence of the electron number density in the upper ionosphere at altitudes above 300 km on solar irradiance implies that the ionosphere at such altitudes was denser by a factor of ten during the periods of solar maxima in solar cycles 22-23. Correspondingly, the trans-terminator fluxes of cold ions and escape fluxes through the tail were also significantly higher. We estimate an increase of total ion losses through the tail during these solar maxima by a factor of 5-6. © 2017 Elsevier Ltd.
Bruyninx C.,Royal Observatory of Belgium |
Habrich H.,Bundesamt fur Kartographie und Geodasie |
Sohne W.,Bundesamt fur Kartographie und Geodasie |
Kenyeres A.,FOMI Satellite Geodetic Observatory |
And 2 more authors.
International Association of Geodesy Symposia | Year: 2012
This paper describes the EUREF Permanent Network (EPN) and the efforts made to monitor and improve the quality of the EPN products and services. It is shown that the EPN is becoming a multi-GNSS tracking network and that the EPN Central Bureau and the Analysis Centers are preparating to include the new satellite signals in their routine operations. Thanks to the EPN Special Project on "Reprocessing", set up early 2009, EPN products with much better quality and homogeneity will be generated. The Special Project on "Real-time analysis" will improve the reliability of the EPN real-time data streams and develop new EPN real-time products. © Springer-Verlag Berlin Heidelberg 2012.
Fritz S.,International Institute For Applied Systems Analysis |
See L.,International Institute For Applied Systems Analysis |
Mccallum I.,International Institute For Applied Systems Analysis |
You L.,Chinese Academy of Agricultural Sciences |
And 47 more authors.
Global Change Biology | Year: 2015
A new 1 km global IIASA-IFPRI cropland percentage map for the baseline year 2005 has been developed which integrates a number of individual cropland maps at global to regional to national scales. The individual map products include existing global land cover maps such as GlobCover 2005 and MODIS v.5, regional maps such as AFRICOVER and national maps from mapping agencies and other organizations. The different products are ranked at the national level using crowdsourced data from Geo-Wiki to create a map that reflects the likelihood of cropland. Calibration with national and subnational crop statistics was then undertaken to distribute the cropland within each country and subnational unit. The new IIASA-IFPRI cropland product has been validated using very high-resolution satellite imagery via Geo-Wiki and has an overall accuracy of 82.4%. It has also been compared with the EarthStat cropland product and shows a lower root mean square error on an independent data set collected from Geo-Wiki. The first ever global field size map was produced at the same resolution as the IIASA-IFPRI cropland map based on interpolation of field size data collected via a Geo-Wiki crowdsourcing campaign. A validation exercise of the global field size map revealed satisfactory agreement with control data, particularly given the relatively modest size of the field size data set used to create the map. Both are critical inputs to global agricultural monitoring in the frame of GEOGLAM and will serve the global land modelling and integrated assessment community, in particular for improving land use models that require baseline cropland information. These products are freely available for downloading from the http://cropland.geo-wiki.org website. © 2015 John Wiley & Sons Ltd.
Topchiev N.P.,RAS Lebedev Physical Institute |
Galper A.M.,National Research Nuclear University MEPhI |
Bonvicini V.,National Institute of Nuclear Physics, Italy |
Adriani O.,National Institute of Nuclear Physics, Italy |
And 71 more authors.
Journal of Physics: Conference Series | Year: 2016
The GAMMA-400 gamma-ray telescope with excellent angular and energy resolutions is designed to search for signatures of dark matter in the fluxes of gamma-ray emission and electrons + positrons. Precision investigations of gamma-ray emission from Galactic Center, Crab, Vela, Cygnus, Geminga, and other regions will be performed, as well as diffuse gamma-ray emission, along with measurements of high-energy electron + positron and nuclei fluxes. Furthermore, it will study gamma-ray bursts and gamma-ray emission from the Sun during periods of solar activity. The GAMMA-400 energy range is expected to be from ∼20 MeV up to TeV energies for gamma rays, up to 10 TeV for electrons + positrons, and up to 1015 eV for cosmic-ray nuclei. For 100-GeV gamma rays, the GAMMA-400 angular resolution is ∼0.01° and energy resolution is ∼1%; the proton rejection factor is ∼5x105. GAMMA-400 will be installed onboard the Russian space observatory.
Duxbury T.C.,George Mason University |
Zakharov A.V.,Institute of Space Research |
Hoffmann H.,German Aerospace Center |
Guinness E.A.,Washington University in St. Louis
Planetary and Space Science | Year: 2014
We review the previous exploration of Phobos and Deimos by spacecraft. The first close-up images of Phobos and Deimos were obtained by the Mariner 9 spacecraft in 1971, followed by much image data from the two Viking orbiters at the end of the 70s, which formed the basis for early Phobos and Deimos shape and dynamic models. The Soviet Phobos 2 spacecraft came within 100 km of landing on Phobos in 1988. Mars Global Surveyor (1996-2006) and Mars Reconnaissance Orbiter (since 2005) made close-up observations of Phobos on several occasions. Mars Express (since 2003) in its highly elliptical orbit is currently the only spacecraft to make regular Phobos encounters and has returned large volumes of science data for this satellite. Landers and rovers on the ground (Viking Landers, Mars Pathfinder, MER rovers, MSL rover) frequently made observations of Phobos, Deimos and their transits across the solar disk. © 2013 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-SA license.
Vaisberg O.L.,Institute of Space Research
Solar System Research | Year: 2012
The manuscript by L. V. Ksanfomality continues the theme published earlier in "Astronomicheskii Vestnik" (Ksanfomality, 2012). The article is of great epistemological interest. The existence of extraterrestrial life that is similar to ours, or strongly differs from it, is one of the most important problems of modern natural science. Where we came from, whether there is any more life in the Universe, whether it differs from ours are questions of interest to both researchers and many thinking people on the Earth. It is not without reason that the search for extraterrestrial life is a focus of the NASA space program. © 2012 Pleiades Publishing, Ltd.
Kryuchkov E.I.,Institute of Space Research |
Fedorenko A.K.,Institute of Space Research
Geomagnetism and Aeronomy | Year: 2012
The dependence of energy transport by acoustic gravity waves (AGWs) on their spectral properties is studied. On the basis of the analysis of expressions for group velocities and energy fluxes of AGWs, it is shown that there exist separate frequencies and wavelengths at which the energy transport in space is most efficient. Comparison of the obtained results with the data of observations on board the Dynamic Explorer 2 satellite shows that, in the upper atmosphere of the Earth's polar regions, AGWs with spectral parameters corresponding to the maximum of energy transport predominate. © 2012 Pleiades Publishing, Ltd.