Karoo Array Telescope site shielding : laboratory, computational and multi-copter studies

[摘要] ENGLISH ABSTRACT: The Northern Cape in South Africa has been chosen to host the Square KilometreArray (SKA) due to the area's overall radio quietness. As part of thesupporting systems for the Karoo Array Telescope (KAT), a processing buildinghas been constructed on the site. With the Karoo Array Processing Building(KAPB) now in place, investigating the radio frequency interference (RFI)of the building has become a high priority. If successful, understanding of RFIpropagation on-site will shape policies and contribute to the sustainability ofon-site radio quietness. This dissertation focuses on understanding the shieldingand propagation characteristics of both the KAPB building, as well as aman-made soil berm. On-site measurements, scale models and computationalmodels will be used to investigate the local electromagnetic environment. Additionally,a Multi-copter vehicle is developed to support on-site measurementcampaigns. Using data measured on-site it was possible to develop empiricalmodels for local shielding estimations. It was found that the shielding performanceof the berm was primarily affected by diffraction. Also, the developedcomputational model makes it possible to investigate alternative terrestrialstructures. The work done in this dissertation will permit off-site analysisof propagation over terrestrial structures. Moreover, the development of aMulti-copter measurement platform creates more efficient metrology. Finally,empirical models are designed so that shielding budgets can be calculated fornoise sources to the nearest receivers.

[发布机构] Stellenbosch University