Academic literature on the topic 'Auvergne Station'

AbstractIn this paper, we derive improved expressions for the harmonic correction to gravity and, for the first time, expressions for the harmonic correction to potential and height anomaly. They need to be applied at stations buried inside the masses to transform internal values into harmonically downward continued values, which are then input to local quasi-geoid modelling using least-squares collocation or least-squares techniques in combination with the remove-compute-restore approach. Harmonic corrections to potential and height anomaly were assumed to be negligible so far resulting in yet unknown quasi-geoid model errors. The improved expressions for the harmonic correction to gravity, and the new expressions for the harmonic correction to potential and height anomaly are used to quantify the approximation errors of the commonly used harmonic correction to gravity and to quantify the magnitude of the harmonic correction to potential and height anomaly. This is done for two test areas with different topographic regimes. One comprises parts of Norway and the North Atlantic where the presence of deep, long, and narrow fjords suggest extreme values for the harmonic correction to potential and height anomaly and corresponding large errors of the commonly used approximation of the harmonic correction to gravity. The other one is located in the Auvergne test area with a moderate topography comprising both flat and hilly areas and therefore may be representative for many areas around the world. For both test areas, two RTM surfaces with different smoothness are computed simulating the use of a medium-resolution and an ultra-high-resolution reference gravity field, respectively. We show that the errors of the commonly used harmonic correction to gravity may be as large as the harmonic correction itself and attain peak values in areas of strong topographic variations of about 100 mGal. Moreover, we show that this correction may introduce long-wavelength biases in the computed quasi-geoid model. Furthermore, we show that the harmonic correction to height anomaly can attain values on the order of a decimetre at some points. Overall, however, the harmonic correction to height anomaly needs to be applied only in areas of strong topographic variations. In flat or hilly areas, it is mostly smaller than one centimetre. Finally, we show that the harmonic corrections increase with increasing smoothness of the RTM surface, which suggests to use a RTM surface with a spatial resolution comparable to the finest scales which can be resolved by the data rather than depending on the resolution of the global geopotential model used to reduce the data.

The thesis addresses the broader theme of coexistence between black and white Australians through an extended case study of the mediation of overlapping Aboriginal ‘heritage’ interests in land with the interests of non-Indigenous landowners and land managers in the Victoria River District of the Northern Territory (the ‘VRD’). The thesis shows that while an historical perspective reveals marked changes in many of the outward manifestations of intercultural relations (for example, changes in white categorisations of Aboriginal people from ‘station blacks’ to ‘Aboriginal custodians’, and changes in the conduct of relations from violent to non-violent behaviours), the overall tenor of relations has changed little. The VRD community remains ‘racially’ segregated, characterised by separate cultural domains, poor intercultural communication and entrenched Aboriginal marginality and socio-economic disadvantage. The thesis shows how recognition of Aboriginal heritage interests in land is largely determined by the parameters of this pattern of relations, which are analysed in the thesis through the themes of power, cultural difference and strategic action. The thesis also examines the Western paradigm of heritage, from its conceptual origins to the structures and processes which have subsequently been developed in Indigenous heritage policy, including heritage protection legislation and processes of consultation. The integration of heritage protection with development approvals processes has created many difficulties for Aboriginal communities in the VRD, whose heritage interests are often placed in opposition to the economic interests of the wider Australian community. The thesis endorses a coexistence approach to mediating Indigenous heritage interests with the interests and needs of non-Indigenous land owners and land managers. This must include effective statutory protection of Indigenous heritage interests together with mechanisms and resources to promote and negotiate voluntary agreements between Indigenous and non-Indigenous stakeholders.