A schema for complex time-dependent transformations between geodetic reference frames

GNSS point-positioning is becoming more precise and accessible to a wider spectrum of non-expert users. As a consequence, the issue of misalignment between GNSS positioning reference frames and spatial data reference frames is increasingly apparent. Positions of ground-fixed features within GNSS frames are kinematic in nature due to global plate motions and other geodynamic effects such as seismic deformation and glacial isostatic adjustment. On the other hand, dense, high resolution spatial data such as imagery and point clouds are not intrinsically kinematic at the moment of acquisition. Misalignment of this data with global reference frames such as those used by GNSS is inevitable unless a rigorous time-dependent transformation accommodating the complexity of global deformation is applied. Spatial data defined by different epochs of a kinematic frame require time-dependent transformations within GIS in order to align the data correctly for the purpose of visualisation and precision analysis. The absence of a transformation schema to handle complex deformation is already impacting significantly on the integrity of high precision spatial data acquired at different epochs. This thesis develops and describes a schema for time-dependent transformations between geodetic reference frames in complex deformation environments. The schema can support geodetic applications including positioning, surveying and spatial data management. Precision requirements for reference frames in practice are assessed taking into consideration the impact of global and local deformations on precision at different spatial and temporal scales. Strategies for the realisation of stable local reference frames using plate motion models are also described. Case studies in Australia and New Zealand are presented showing the significant improvement in precision and reference frame longevity that can result by application of the schema for geodetic applications in complex deformation zones. The case studies are characterised by very different tectonic settings to highlight the flexibility of the schema