Voyager 1: cleaning magnetic field data for turbulence studies
Author(s) | Cuesta, Manuel Enrique | |
Date Accessioned | 2021-02-12T18:31:11Z | |
Date Available | 2021-02-12T18:31:11Z | |
Publication Date | 2020 | |
SWORD Update | 2020-10-12T19:03:47Z | |
Abstract | In this project the quality of the publicly available magnetic field data from Goddard Space Flight Center Space Physics Data Facility (SPDF) for NASA's Voyager 1 spacecraft was examined. While investigating turbulence intermittency throughout the solar wind using Voyager 1 magnetic field data, various issues with timestamps and types of data pollution were discovered, rendering the data unusable. Turbulence intermittency corresponds to irregular passing of eddies and structures through a specified region. According to SPDF, the data supplied on the public website should have a $1.92$ second resolution, which is not the case. Additionally, instrument calibrations and nonphysical noise are present and not tracked by SPDF. For these reasons, this dataset requires extensive improvements to arrive at a dataset suitable for scientific research. This thesis describes the cleaning processes required to extract the physical measurements from this dataset. These processes include attempts of autonomous cleaning, manual assessment, and the application of a Hampel filter. ☐ In order to examine intermittency statistics from 1 to 10 Astronomical Units (au) using Voyager 1 data, the highest available resolution (1.92 second cadence) magnetic field series must be cleaned. This will enable these quantities to be computed on the order of an ion inertial length (di). In fact, the dataset, once cleaned, demonstrates through calculation that it can resolve down to 10 di, which approaches the edge of the turbulence inertial range. This dataset is of historical importance and of substantial scientific value, so some effort is warranted to improve its quality and usability. The procedures for this data cleaning are described here. To complete the refined data product, hourly-averaged measurements for certain plasma parameters were retrieved and resampled to match the resolution of the magnetic field data. Also, confirmation of the effectiveness of the cleaning techniques is pursued in this thesis. This is achieved by computing correlation lengths (λc) and ion inertial lengths and comparing these quantities to NASA's Helios 1 spacecraft observations. The final product presented in this study is a dataset suitable for future scientific investigations. | en_US |
Advisor | Matthaeus, William H. | |
Degree | M.S. | |
Department | University of Delaware, Department of Physics and Astronomy | |
Unique Identifier | 1237369006 | |
URL | https://udspace.udel.edu/handle/19716/28715 | |
Language | en | |
Publisher | University of Delaware | en_US |
URI | https://login.udel.idm.oclc.org/login?url=https://www.proquest.com/dissertations-theses/voyager-1-cleaning-magnetic-field-data-turbulence/docview/2456878604/se-2?accountid=10457 | |
Keywords | Magnetic field | |
Keywords | Solar wind | |
Keywords | NASA Voyager 1 | |
Keywords | Goddard Space Flight Center Space Physics Data Facility | |
Keywords | Turbulence intermittency | |
Keywords | Data pollution | |
Keywords | Data recovery | |
Keywords | Instrument calibrations | |
Keywords | Astronomical Units | |
Keywords | NASA Helios 1 | |
Title | Voyager 1: cleaning magnetic field data for turbulence studies | en_US |
Type | Thesis | en_US |