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- Hudson, Lawrence N, et al.
(författare)
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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project
- 2017
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Ingår i: Ecology and Evolution. - : John Wiley & Sons. - 2045-7758. ; 7:1, s. 145-188
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Tidskriftsartikel (refereegranskat)abstract
- The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.
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| 2. |
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| 3. |
- Sünter, I., et al.
(författare)
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Design and testing of a dual-camera payload for ESEO
- 2016
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Ingår i: Proceedings of the International Astronautical Congress, IAC. - : International Astronautical Federation, IAF.
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Konferensbidrag (refereegranskat)abstract
- Since 2012, European Space Agency (ESA), SITAEL and ten European universities have been developing the European Student Earth Orbiter (ESEO). The satellite bus is being designed, built and tested by SITAEL, whereas the payload modules are being developed by various universities throughout Europe. ESEO is a microsatellite to measure the radiation environment in Low Earth Orbit (LEO), test new technologies in space as well as take photos of Earth and other celestial bodies. The aim of the ESEO optical payload is to produce color images in the visible spectrum, mainly for public outreach purposes. Although, in addition to public outreach, the payload can also be used to monitor plankton blooms or changes in the polar ice caps. This paper presents the design, development and pre-launch testing of a lightweight and power-efficient dual-camera system for ESEO. The two-camera solution enables imaging of the same target with a different field of view. The wide angle camera provides context for telescopic images, making it easier to pinpoint the area that was photographed. The primary camera of the payload is a wide-angle camera based on the ESTCube-1 design with a 4.4 mm telecentric lens, VGA CMOS color sensor and a 700 nm IR cut-off filter. With a field of view of 46° × 35°, the ground resolution of the primary camera is around 1 km per pixel. The secondary camera is telescopic, has a Zeiss C Sonnar T∗ 1.5/50 lens, a 2592×1944 pixel CMOS color sensor and a Schott BG40 filter. With a field of view of 6.63° × 5°, the ground resolution of the secondary camera is about 20 m per pixel. The payload features configurable internal image processing, progressive image compression and non-volatile storage. The resulting payload weighs about 800 g, on average consumes less than 560 mW of power, with peaks up to 1.5 W. The payload is currently being tested and will be launched on ESEO at the end of 2016.
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| 4. |
- Palos, Mario F., et al.
(författare)
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Electric Sail Mission Expeditor, ESME : Software Architecture and Initial ESTCube Lunar Cubesat E-Sail Experiment Design
- 2023
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Ingår i: Aerospace. - : MDPI AG. - 2226-4310. ; 10:8
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Tidskriftsartikel (refereegranskat)abstract
- The electric solar wind sail, or E-sail, is a novel deep space propulsion concept which has not been demonstrated in space yet. While the solar wind is the authentic operational environment of the electric sail, its fundamentals can be demonstrated in the ionosphere where the E-sail can be used as a plasma brake for deorbiting. Two missions to be launched in 2023, Foresail-1p and ESTCube-2, will attempt to demonstrate Coulomb drag propulsion (an umbrella term for the E-sail and plasma brake) in low Earth orbit. This paper presents the next step of bringing the E-sail to deep space—we provide the initial modelling and trajectory analysis of demonstrating the E-sail in solar wind. The preliminary analysis assumes a six-unit cubesat being inserted in the lunar orbit where it deploys several hundred meters of the E-sail tether and charges the tether at 10–20 kV. The spacecraft will experience acceleration due to the solar wind particles being deflected by the electrostatic sheath around the charged tether. The paper includes two new concepts: the software architecture of a new mission design tool, the Electric Sail Mission Expeditor (ESME), and the initial E-sail experiment design for the lunar orbit. Our solar-wind simulation places the Electric Sail Test Cube (ESTCube) lunar cubesat with the E-sail tether in average solar wind conditions and we estimate a force of (Formula presented.) N produced by the Coulomb drag on a 2 km tether charged to 20 kV. Our trajectory analysis takes the 15 kg cubesat from the lunar back to the Earth orbit in under three years assuming a 2 km long tether and 20 kV. The results of this paper are used to set scientific requirements for the conceptional ESTCube lunar nanospacecraft mission design to be published subsequently in the Special Issue “Advances in CubeSat Sails and Tethers”.
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