Review of current radiometer technology with suggestions for future South African satellites

Includes bibliographical references (p. 134-176)Given that South Africa is an emerging space nation, in a continent of emerging space nations and economies, several technologies need to be developed to progress the space program into a viable and sustainable endeavour. The three main areas of space technology are communications, navigation and remote sensing. Earth science is strongly reliant on the third of these areas for obtaining global scientific data, on a suitable temporal/spatial scale. One of the forms of electro-magnetic remote sensing is microwave radiometry. This dissertation presents a short review of currently available space-faring radiometer technologies and applications, which are then discussed in the context of today's South Africa. For instance Passive Microwave Radiometers (PMR) in the L-Band have huge implications in Soil Moisture (SM) and Sea Salinity (SSS), which in turn affect the global climate, and are being investigated by current and soon to launch missions such as Aquarius, SMOS and SMAP. Multi-frequency radiometers are used to classify various other aspects of Earth's surface-atmosphere system. The structure of this dissertation is to introduce the concepts of radiometry with a review of current and future radiometers from literature (up to November 2011). The user communities, current and possible, are also analysed. There is a discussion of South Africa's history, needs and presence in space, along with possible constraints on a future South African instrument going to space. A technology demonstrator passive microwave radiometer, for SM and Sea Surface Temperature (SST) along with some atmospheric correction channels, is presented. Synergy with data obtained from other instruments, such as an Infra-Red (IR) sounder, is also discussed