Visualization Principles in 3D Cadastre: A First Assessment of Visual Variables

This paper proposes to investigate which among visual variables are more appropriate (if they are) for geo-visualization of 3D legal units in a probable 3D cadastre system. Visual variables, as proposed by Bertin (1983), include position, size, shape, value, color, orientation and texture. The appropriateness is evaluated base on whether a visual variable can be selective or not in the context of visualising 3D cadastral features. From a literature review, five requirements are identified and used to carry out the assessment. Namely they are represent bounded and partial bounded 3D legal units, represent the relationship between 3D legal units and 2D land parcels, represent the relationship of 3D legal units with corresponding physical object, represent spatial relationships among 3D legal units and label with official measurements. The results clearly show that changing the position of the visual variable for selectivity purpose is not an adequate strategy, except to distinguish bounded and unbounded 3D legal units. A change in size of point and line or in color is fully suitable no matter is the requirement. If there is light source and shading effect in 3D cadastre visualization, value is not a promising choice. However, in a self-illuminating situation, in which there is no light source and shading effect, value could be used to represent all situations. Labeling with official measurements is the requirement the least fulfil

Transparency Performance in the 3D Visualization of Bounding Legal and Physical Objects: Preliminary Results of a Survey

This paper presents a third, subsequent, experiment to assess the performance of various visual variables for better visualization of 3D cadastre models. The case study is a 3D spatial representation of an apartment building with co-ownership units. The third experiment focuses on the following hypotheses “Transparency is performing to distinguish two groups of bounding objects such as physical (e.g., walls) and legal (administrative units) and to give the impression of ownership”. These objects are distinct and essential for use by notaries, one category of user of 3D cadastre models, since the spatial relationships between them may directly influence the determination of ownership, and the associated rights and responsibilities. The methodology is based on online questionnaire showing twelve 3D models where participants are invited to test their ability to decide if the wall of a specific apartment belonged to them or not. For data analysis, groups of participants are categorized according to being skilled in cadastral data manipulation, and in 3D data visualization. This paper presents preliminary results of those tests

3D Cadastre Visualization: Recent Progress and Future Directions

The 3D Cadastre has been investigated from many viewpoints (including legal, organizational and technical). However, to date little research has focused specifically on visualizationrelated aspects despite the value-added of the third dimension. The paper first proposes an overview of progress made in the last five years in 3D cadastral visualization. The authors then summarize discussions at the 2014 3D Cadastre workshop regarding future research and development on the topic. This synthesis is complemented by a broad review of the most recent advances in 3D visualization beyond the 3D cadastral domain, with the goal of providing a number of important directions for further work, allowing researchers, developers and users to consolidate their respective activities, and encouraging collaboration

Modeling the Dynamics of the Atmospheric Boundary Layer Over the Antarctic Plateau With a General Circulation Model

Observations evidence extremely stable boundary layers (SBL) over the Antarctic Plateau and sharp regime transitions between weakly and very stable conditions. Representing such features is a challenge for climate models. This study assesses the modeling of the dynamics of the boundary layer over the Antarctic Plateau in the LMDZ general circulation model. It uses 1 year simulations with a stretched-grid over Dome C. The model is nudged with reanalyses outside of the Dome C region such as simulations can be directly compared to in situ observations. We underline the critical role of the downward longwave radiation for modeling the surface temperature. LMDZ reasonably represents the near-surface seasonal profiles of wind and temperature but strong temperature inversions are degraded by enhanced turbulent mixing formulations. Unlike ERA-Interim reanalyses, LMDZ reproduces two SBL regimes and the regime transition, with a sudden increase in the near-surface inversion with decreasing wind speed. The sharpness of the transition depends on the stability function used for calculating the surface drag coefficient. Moreover, using a refined vertical grid leads to a better reversed “S-shaped” relationship between the inversion and the wind. Sudden warming events associated to synoptic advections of warm and moist air are also well reproduced. Near-surface supersaturation with respect to ice is not allowed in LMDZ but the impact on the SBL structure is moderate. Finally, climate simulations with the free model show that the recommended configuration leads to stronger inversions and winds over the ice-sheet. However, the near-surface wind remains underestimated over the slopes of East-Antarctica.Atmospheric Remote Sensin