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Pretoria, South Africa

The South African National Space Agency is South Africa's government agency responsible for the promotion and development of aeronautics and aerospace space research. It fosters cooperation in space-related activities and research in space science, seeks to advance scientific engineering through human capital, as well as the peaceful use of outer space, and supports the creation of an environment conducive to the industrial development of space technologies within the framework of national government.SANSA was established on 9 December 2010 by the National Space Agency Act.Currently, SANSA's main focusses include using data obtained from remote sensing through satellites and other projects to provide assessment on flooding, fires, resource management and environmental phenomena in South Africa and the African continent. Wikipedia.

Yamazaki Y.,Lancaster University | Kosch M.J.,Lancaster University | Kosch M.J.,The South African National Space Agency
Journal of Geophysical Research A: Space Physics | Year: 2014

This paper describes long-term changes in the geomagnetic lunar (L) and solar (S) daily variations. We analyze the eastward component of the geomagnetic field observed at eight midlatitude stations during 1903-2012. The amplitude and phase for the semidiurnal component of the L and S variations are examined. Both L and S amplitudes correlate with the solar activity index F10.7, revealing a prominent 11 year solar cycle. In both cases, the correlation is slightly better with √F10.7 than F10.7. The v sensitivity of the L variation to solar activity is comparable with that of the S variation. The solar cycle effect is also found in the phase of the S variation but not apparent in the phase of the L variation. The ratio in the amplitude of the L to S variation shows a long-term decrease (approximately 10% per century), which may be due to a reduction in lunar tidal waves from the lower atmosphere to the upper atmosphere in association with climate change. © 2014. The Authors. Source

Long D.M.,University College London | Bloomfield D.S.,Trinity College Dublin | Gallagher P.T.,Trinity College Dublin | Perez-Suarez D.,The South African National Space Agency
Solar Physics | Year: 2014

The continuous stream of data available from the Atmospheric Imaging Assembly (AIA) telescopes onboard the Solar Dynamics Observatory (SDO) spacecraft has allowed a deeper understanding of the Sun. However, the sheer volume of data has necessitated the development of automated techniques to identify and analyse various phenomena. In this article, we describe the Coronal Pulse Identification and Tracking Algorithm (CorPITA) for the identification and analysis of coronal "EIT waves". CorPITA uses an intensity-profile technique to identify the propagating pulse, tracking it throughout its evolution before returning estimates of its kinematics. The algorithm is applied here to a data set from February 2011, allowing its capabilities to be examined and critiqued. This algorithm forms part of the SDO Feature Finding Team initiative and will be implemented as part of the Heliophysics Event Knowledgebase (HEK). This is the first fully automated algorithm to identify and track the propagating "EIT wave" rather than any associated phenomenon and will allow a deeper understanding of this controversial phenomenon. © 2014 Springer Science+Business Media Dordrecht. Source

Kotze P.B.,The South African National Space Agency
South African Journal of Geology | Year: 2011

Quiet-time mean monthly values from the INTERMAGNET observatory at Hermanus (HER) in South Africa were used to study the changes in secular variation during the period between 2005 and 2009. After removing an annual variation resulting from magnetospheric and ionospheric currents by means of a 12-month running means applied to the respective observatory first differences of the X, Y, and Z components, clear evidence was revealed of a strong geomagnetic jerk that occurred during 2007 in this area. The GRIMM-2X model also provided evidence of the occurrence of this jerk in 2007. Of particular interest is that GRIMM-2X predicts the turning points in all the secular variation trends to occur much earlier than revealed by the observatory data. We also observed that the power of this jerk, determined as the difference in slope of the secular variation before and after the jerk, is several times stronger than the global jerk of 1982/3. © 2011 June Geological Society of South Africa. Source

Odindi J.O.,University of KwaZulu - Natal | Mhangara P.,The South African National Space Agency
International Journal of Environmental Research | Year: 2012

Given the critical role played by urban green spaces and the emergence of remote sensing as a valuable natural resource management tool, this study sought to identify trends in green spaces within the context of South Africa's transition period (1990 - 2000). Using the city of Port Elizabeth as a case study, three sets of Landsat - 5 Thematic Mapper images (1990, 1995 and 2000) were geo-processed, classified into vegetation density categories and verified using respective aerial photographs. There was a steady decline in areas covered by Very sparse vegetation, Sparse vegetation and Dense vegetation classes. However, areas covered by Very dense vegetation showed a steady increase during the study period. Using remote sensing applications, this study provides an insight into trends in green spaces in the city of Port Elizabeth during the transition period. This study further shows the importance of remote sensing as a mapping tool that can be used to provide information for physical, social and ecological planning to achieve urban socio-ecological sustainability in rapidly changing urban environments. Source

The security of space assets are affected by the high-energy charged particle environment in the radiation belts. The controlling principal source and loss mechanisms in the radiation belts are not yet completely understood. During a geomagnetic storm the length of time during which space assets are in danger is determined by the loss mechanisms, particularly by relativistic electron precipitation. The primary mechanism for this precipitation is the interaction of several wave modes with resonant electrons which leads to scattering into the atmospheric loss cone. The nature of the wave activity and the interactions between the waves and radiation belt particles are strongly governed by the properties of the plasmasphere. At this point there are few existing and regular measurements of plasmaspheric properties, with existing plasmaspheric models lacking the structures known to exist in the real plasmasphere. There is evidence that enhanced wave activity and enhanced radiation belt losses occur due to such structures. In addition, there are large uncertainties concerning the fundamental nature of relativistic electron precipitation (REP), due to the difficulties of undertaking quality in-situ measurements. To address these uncertainties in this proposed project we will provide regular longitudinally-resolved measurements plasmaspheric electron and mass densities and hence monitor the changing composition of the plasmasphere, one of the properties which determines wave growth. This will allow us to develop a data assimilative model of the plasmasphere. At the same time, we will monitor the occurrence and properties of REP, tying the time-resolved loss of relativistic electrons to the dynamic plasmasphere observations. Our approach will primarily use ground-based networks of observing stations, operating in the ULF and VLF ranges, deployed on a worldwide level. Our proposal is made up of 6 work packages to meet these science goals.

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