Change search
ReferencesLink to record
Permanent link

Direct link
Venus Thermosphere Densities as Revealed by Venus Express Torque and Accelerometer Data
2015 (English)Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

The Venus Express spacecraft is the most recent spacecraft to orbit around the planet Venus. During the years 2008 to 2014 it made several successful campaigns in which it was submerged into the upper atmosphere. By using the force exerted on the spacecraft during these campaigns of different pericentre altitudes three data sets were obtained: the so called radio tracking, torque and accelerometry. These three data sets have been used to calculate the density and its variations, in the altitude range 130-200 km, in order to understand more about the Venusian atmosphere.In this project the densities from the torque method have been calculated and used, together with the previously calculated accelerometry data, in order to determine the mean atmospheric state and the variabilities. The previously calculated tracking densities have been used as a validation method. These results have inferred a mean state with 40 % lower densities in the polar atmosphere compared to the Hedin model predictions and a factor of two stronger solar zenith angle (SZA) dependence for higher altitudes than was previously modelled in the Hedin model. A high rate of variability was found, a factor of 7 between maximum and minimum of the observed densities once height and SZA dependence have been considered, in the upper atmosphere which is currently unexplained. This project therefore gives many suggestions for further work in order to give a better understanding and improve the results achieved.

Place, publisher, year, edition, pages
Keyword [en]
Keyword [sv]
Teknik, Venus Express, Venus, Thermosphere, Torque, Accelerometer, Density
URN: urn:nbn:se:ltu:diva-48480Local ID: 5edff2bd-9fb7-4a6b-887c-a00c06577a5dOAI: diva2:1021822
External cooperation
Subject / course
Student thesis, at least 30 credits
Educational program
Space Engineering, master's level
Validerat; 20151015 (global_studentproject_submitter)Available from: 2016-10-04 Created: 2016-10-04Bibliographically approved

Open Access in DiVA

fulltext(1528 kB)0 downloads
File information
File name FULLTEXT02.pdfFile size 1528 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Persson, Moa

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

ReferencesLink to record
Permanent link

Direct link