Signal Processing for the Measurement of the Deuterium/Hydrogen Ratio in the Local Interstellar Medium

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

[img]
Preview
Text
entropy-16-01134.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (4MB) | Preview

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.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences

UniBE Contributor:

Rodriguez Moreno, Diego Francisco and Wurz, Peter

Subjects:

500 Science > 530 Physics

ISSN:

1099-4300

Publisher:

MDPI

Language:

English

Submitter:

Cléa Serpollier

Date Deposited:

16 Apr 2015 09:20

Last Modified:

16 Apr 2015 09:20

Publisher DOI:

10.3390/e16021134

BORIS DOI:

10.7892/boris.66765

URI:

https://boris.unibe.ch/id/eprint/66765

Actions (login required)

Edit item Edit item
Provide Feedback