Signal Processing for the Measurement of the Deuterium/Hydrogen Ratio in the Local Interstellar Medium
| Autor: | L. Saul, Diego Francisco Rodríguez Moreno, Eberhard Möbius, M. A. Kubiak, Maciej Bzowski, Justyna M. Sokół, Nathan A. Schwadron, David J. McComas, Priscilla C. Frisch, Peter Wurz, Stephen A. Fuselier |
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| Rok vydání: | 2014 |
| Předmět: |
530 Physics
General Physics and Astronomy lcsh:Astrophysics Astrophysics Signal IBEX-Lo lcsh:QB460-466 lcsh:Science deuterium ISM Physics Earth's orbit energetic neutral atoms D/H ratio 3D-TOF analysis Spacecraft business.industry lcsh:QC1-999 Interstellar medium Time of flight Deuterium 13. Climate action Physics::Space Physics lcsh:Q Satellite Astrophysics::Earth and Planetary Astrophysics business lcsh:Physics Energy (signal processing) |
| Zdroj: | Entropy; Volume 16; Issue 2; Pages: 1134-1168 Entropy Rodriguez Moreno, Diego Francisco; Wurz, Peter; Saul, Lukas; Bzowski, Maciej; Kubiak, Marzena; Sokół, Justyna; Frisch, Priscilla; Fuselier, Stephen; McComas, David; Möbius, Eberhard; Schwadron, Nathan (2014). Signal Processing for the Measurement of the Deuterium/Hydrogen Ratio in the Local Interstellar Medium. Entropy, 16(2), pp. 1134-1168. MDPI 10.3390/e16021134 Entropy, Vol 16, Iss 2, Pp 1134-1168 (2014) |
| ISSN: | 1099-4300 |
| DOI: | 10.3390/e16021134 |
| Popis: | We report on a comprehensive signal processing procedure for very low signal levels for the measurement of neutral deuterium in the local interstellar medium from a spacecraft in Earth orbit. The deuterium measurements were performed with the IBEX Lo camera on NASA’s Interstellar Boundary Explorer (IBEX) satellite. Our analysis technique for these data consists of creating a mass relation in three dimensional time of flight space to accurately determine the position of the predicted D events to precisely model the tail of the H events in the region where the H tail events are near the expected D events and then to separate the H tail from the observations to extract the very faint D signal. This interstellar D signal which is expected to be a few counts per year is extracted from a strong terrestrial background signal consisting of sputter products from the sensor’s conversion surface. As reference we accurately measure the terrestrial D/H ratio in these sputtered products and then discriminate this terrestrial background source. During the three years of the mission time when the deuterium signal was visible to IBEX the observation geometry and orbit allowed for a total observation time of 115.3 days. Because of the spinning of the spacecraft and the stepping through eight energy channels the actual observing time of the interstellar wind was only 1.44 days. With the optimised data analysis we found three counts that could be attributed to interstellar deuterium. These results update our earlier work. |
| Databáze: | OpenAIRE |
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