Virtual 3d Mapping and Analysis Using Remote Sensing Data and Photographs
With the rapid growth of urbanization, visualization in the three-dimensional aspect is getting more importance nowadays. 3D modeling and visualization techniques help in decision making process to understand the third dimensional features in cities. Planners, urban designers, landscape architects and other planning professionals use computerized vi-sualization techniques to encourage the participation of public in urban planning. Aerial and Satellite images can be used to generate 3D models, but they cannot give a realistic feel due to the absence of texture information. The objective of this study is to build a 3D model along with texture information using currently available software tools and to make it freely viewable for the public. High resolution satellite data are useful for 3D mapping and analysis. In the current study, field photographs and satellite images are used to create 3D database of few iconic buildings in Bangalore city. Satellite images are used to identify the georeferenced footprint of the buildings or features. The designing and creation of 3D database is carried out using Sketchup software tools. Texture information is added from the photographs to get a realistic feel of the 3D building. The 3D features are visualized in Arcscene using Digital Elevation Model (DEM) and orthorectified high resolution Satellite data. Further, techniques have been employed to generate a 3D cadastre prototype for visualization of vertical growth of buildings. Line of sight and shadow analysis was carried out using the 3D model analyst toolbar in Arcscene for understanding the potential of this technology for locating security cameras.
A novel framework for seamless mosaic of Cartosat-1 DEM scenes
Abstract Digital elevation model (DEM) is used as a source of elevation data in wide range of applications. The applications involving larger area than an individual DEM scene often need a mosaic of DEM scenes. A simple stitching exhibits seams along the borders of DEM scenes in the mosaic output. The presence of seam lines varies with the number of scenes in an overlapping region and their overlap extents. The conventional feathering-based blend method, by virtue of the method itself, considers only two input scenes in an instance of the mosaic process. This method requires a suitable ordering of the input DEM scenes, especially in the overlapping regions containing more than two scenes. In this paper, we propose a framework that automatically handles the multiple overlapping regions and creates a seamless mosaic of Cartosat-1 DEM scenes for a given region of interest. We use a tree data structure to arrange input DEM scenes hierarchically based on their metadata. A traversal algorithm is devised to establish an order of precedence among the DEM scenes. This determines a unique input sequence of DEM scenes during mosaic process. In addition, two variants of feathering-based blend method are formulated to handle all possible cases of the overlapping regions. The experiments have been conducted on Cartosat-1 DEM scenes over 1 ° × 1 ° region of interest. We analyze and compare our proposed methodology with average method and feathering-based blend method. We demonstrate that our framework exhibits a smooth transition of elevation values in the overlapping regions of the DEM mosaic output.
“To those who choose to follow in our footsteps”: making women/LGBT+ soldiers (in)visible through feminist “her-story” theater
Building on Judith Butler ’ s understanding of visibility as “ the object of continuous regulation and contestation, ” art/aesthetics studies in international relations, and feminist theater studies, we identify feminist “ her-story ” theater as a unique site where Western “ gender-/sexuality-inclusive ” soldiering is visibilized, contested, and subverted. Drawing on ethnographic observations of two award-winning dramas, interviews with artists and military hosts, and ﬁ ndings from a wider research project on contemporary British military culture, we reveal the key role of heteronormative and patriarchal cultural discourses in reproducing the ambivalent positionalities of women/LGBT+ soldiers. We argue that the very visibility of women/LGBT+ soldiers on the stage paradoxically operates to make the complexities of – and struggles against – masculinized heteronormative military cultures invisible. Furthermore, despite artists ’ attempts to dissociate empowerment through soldiering from the problematic context of modern con ﬂ icts, “ her-story ” theater ultimately entrenches gendered/racialized hierarchies that normalize Western military interventions. We conclude that only through sustained feminist re ﬂ ection on the contours of “ imagined ” futures of female/ LGBT+ soldiering can this persistently problematic (in)visibility be productively disrupted.