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Pascale E.,University of Cardiff | Waldmann I.P.,University College London | MacTavish C.J.,University of Cambridge | Papageorgiou A.,University of Cardiff | And 11 more authors.
Experimental Astronomy | Year: 2015

EChOSim is the end-to-end time-domain simulator of the Exoplanet Characterisation Observatory (EChO) space mission. EChOSim has been developed to assess the capability of the EChO mission concept to detect and characterise the atmospheres of transiting exoplanets. Here we discuss the details of the EChOSim implementation and describe the models used to represent the instrument and to simulate the detection. Software simulators have assumed a central role in the design of new instrumentation and in assessing the level of systematics affecting the measurements of existing experiments. Thanks to its high modularity, EChOSim can simulate basic aspects of several existing and proposed spectrometers including instruments on the Hubble Space Telescope and Spitzer, ground-based and balloon-borne experiments. A discussion of different uses of EChOSim is given, including examples of simulations performed to assess the EChO mission. © 2015, The Author(s). Source


Araujo-Hauck C.,University of Cologne | Fischer S.,University of Cologne | Gillessen S.,Max Planck Institute for Extraterrestrial Physics | Straubmeier C.,University of Cologne | And 11 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2012

A two stage blocking system is implemented in the GRAVITY science and the fringe tracking spectrometer optical design. The blocking system consists of a dichroic beam splitter and two long wave band-pass filters with the top level requirements of high transmission of the science light in the K-Band (1.95 - 2.45 μm) region and high blocking power optical density (OD) ≥ 8 for each filter at the metrology laser wavelength of 1.908 μm. The laser metrology blocking filters were identified as one critical optical component in the GRAVITY science and fringe tracker spectrometer design. During the Phase-C study of GRAVITY all the filters were procured and individually tested in terms of spectral response at K-band, transmission, blocking (OD) and reflection at the metrology laser wavelength. We present the measurements results of the full metrology blocking system in its final configuration as to be implemented in the GRAVITY spectrometers. © 2012 SPIE. Source


Araujo-Hauck C.,University of Cologne | Fischer S.,University of Cologne | Bartko H.,Max Planck Institute for Extraterrestrial Physics | Gillessen S.,Max Planck Institute for Extraterrestrial Physics | And 11 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

A two stage blocking system is implemented in the GRAVITY science and the fringe tracking spectrometer optical design. The blocking system consists of a dichroic mirror and a long wave band-pass filter with the top level requirements of high transmission of the science light in the K-Band (1.95 - 2.5 μm) region and high blocking power optical density (OD) ≥ 8 for the metrology laser wavelength at 1.908 μm. The laser metrology blocking filters have been identified as one critical optical component in the GRAVITY science and fringe tracker spectrometer design. During the Phase-B study of GRAVITY we procured 3 blocking filter test samples for demonstration and qualification tests. We present the measurements results of an effective blocking of the metrology laser wavelength with a long wave band-pass filter at OD=12. © 2010 SPIE. Source


Segret B.,Laboratoire dEtudes Spatiales et dInstrumentation en Astrophysique | Semery A.,Laboratoire dEtudes Spatiales et dInstrumentation en Astrophysique | Vannitsen J.,National Cheng Kung University | Mosser B.,Laboratoire dEtudes Spatiales et dInstrumentation en Astrophysique | And 5 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

The AGILE principles in the software industry seems well adapted to the paradigm of CubeSat missions that involve students for the development of space missions. Some of well-known engineering and program processes are revisited on the example of an interplanetary CubeSat mission profile that has been developed by several teams of students in various countries and at various educational levels since 02/2013. The lessons learned at adapting traditional space mission methods are emphasized and they produce a metaphoric image of paving stones. © 2014 SPIE. Source


Clark B.E.,Ithaca College | Ziffer J.,University of Southern Maine | Nesvorny D.,Southwest Research Institute | Campins H.,University of Central Florida | And 11 more authors.
Journal of Geophysical Research E: Planets | Year: 2010

B-type asteroids have a negative slope from ∼0.5 to ∼1.1 m and beyond. What causes this? Visible to near-infrared reflectance spectra (0.4-2.5 m) are assembled for 22 B-type asteroids. The spectra fall naturally into three groups: (1) those with negative (blue) spectral shapes like 2 Pallas (7 objects), (2) those with concave curve shapes like 24 Themis (11 objects), and (3) everything else (4 objects). The asteroid spectra are compared to mineral and meteorite spectra from the Reflectance Experiment Laboratory library of 15,000 samples, in a least squares search for particulate analogs, constrained by spectral brightness. The Pallas group objects show a trend of analogs from the CV, CO, and CK meteorite groups. Only three of the seven Pallas-like objects are determined to be dynamically related (2, 1508, and 6411). The Themis group objects show a trend of analogs from the CI, CM, CR, CI-Unusual, and CM-Unusual meteorites (as expected from the work of Hiroi et al. (1996)). Seven of the 11 Themis-like objects are dynamically related (24, 62, 222, 316, 379, 383, and 431). Allowing for reasonable uncertainties in the spectral matches, we find no need to invoke mineralogies that do not exist in the meteorite collection to explain B-type spectra or their negative slopes. Our Themis group results are as expected and are consistent with previous work, but our Pallas group results are new and, in some cases, in conflict with previous work. © 2010 by the American Geophysical Union. Source

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