We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham e-Theses
You are in:

Atmospheric monitoring for the H.E.S.S. experiment using a single scattering lidar

Rulten, Cameron Boyd (2009) Atmospheric monitoring for the H.E.S.S. experiment using a single scattering lidar. Masters thesis, Durham University.



The High Energy Stereoscopic System (H.E.S.S.) is an array of 4 telescopes located in Namibia, which use the imaging atmospheric Cherenkov technique (IACT) to study astrophysical emission of gamma radiation in the energy window from 100 GeV to 50 TeV. The calorimetric nature of the technique means that the sensitivity and energy resolution of the instrument are highly dependent on atmospheric parameters. This thesis presents the findings of atmospheric measurements taken using a 355 nm single scattering lidar. The lidar wavelength is well matched to the maximum in the Cherenkov spectrum seen by the telescopes. Monte Carlo simulation software is presented which has been developed to calculate the integral vertical lidar ratio (the ratio of extinction to backscatter) for Mie scattering by aerosols assumed to be at the H.E.S.S. site. This is found to be 29 ± 3 steradians. This ratio is used with the Fernald method to derive the probability of transmission profile, and is also compared to other lidar analysis techniques; the Klett method and the multi-angle method. The results of all 3 methods are compared to the lidar manufacturer's closed-source analysis software, with which the Klett method is found to be in strongest agreement. A model that describes the relationship between the lidar ratio and the extinction is presented. Using this with the lidar manufacturer's extinction values provides a vertical lidar ratio profile which, for the first time, provides insight into the aerosol scattering layers present at the H.E.S.S. site in Namibia. Recommendations for improvement of this research, and suggestions for incorporation of data into the H.E.S.S. analysis, have been made

Item Type:Thesis (Masters)
Award:Master of Science
Thesis Date:2009
Copyright:Copyright of this thesis is held by the author
Deposited On:08 Sep 2011 18:24

Social bookmarking: del.icio.usConnoteaBibSonomyCiteULikeFacebookTwitter