Terrain representation is the manner by which elevation data are visualized. Data are typically stored as 2.5D grid representations, including digital elevation models (DEMs) in raster format and triangulated irregular networks (TINs). These models facilitate terrain representations such as contours, shaded relief, spot heights, and hypsometric tints, as well as automate calculations of surface derivatives such as slope, aspect, and curvature. 3D effects have viewing directions perpendicular (plan), parallel (profile), or panoramic (oblique view) to the elevation’s vertical datum plane. Recent research has focused on automating, stylizing, and enhancing terrain representations. From the user’s perspective, representations of elevation are measurable or provide a 3D visual effect, with much overlap between the two. The ones a user can measure or derive include contours, hypsometric tinting, slope, aspect, and curvature. Other representations focus on 3D effect and may include aesthetic considerations, such as hachures, relief shading, physiographic maps, block diagrams, rock drawings, and scree patterns. Relief shading creates the 3D effect using the surface normal and illumination vectors with the Lambertian assumption. Non-plan profile or panoramic views are often enhanced by vertical exaggeration. Cartographers combine techniques to mimic or create mapping styles, such as the Swiss-style.
Assess the involvement of non-GIS companies (e.g., Microsoft, Google) in the geospatial industry
Describe three applications of geospatial technology for different workforce domains (e.g., first responders, forestry, water resource management, facilities management)
Explain why software products sold by U.S. companies may predominate in foreign markets, including Europe and Australia
Describe the U.S. geospatial industry including vendors, software, hardware and data
Define the following terms pertaining to a network: Loops, multiple edges, the degree of a vertex, walk, trail, path, cycle, fundamental cycle
List definitions of networks that apply to specific applications or industries
Create an adjacency table from a sample network
Explain how a graph can be written as an adjacency matrix and how this can be used to calculate topological shortest paths in the graph
Create an incidence matrix from a sample network
Explain how a graph (network) may be directed or undirected
Demonstrate how attributes of networks can be used to represent cost, time, distance, or many other measures
Demonstrate how the star (or forward star) data structure, which is often employed when digitally storing network information, violates relational normal form, but allows for much faster search and retrieval in network databases
Discuss some of the difficulties of applying the standard process-pattern concept to lines and networks
Demonstrate how a network is a connected set of edges and vertices
DM-46 - Systematic methods