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Geodesy Fundamentals
Published in Julio Sanchez, Maria P. Canton, William Perrizo, Space Image Processing, 2018
Julio Sanchez, Maria P. Canton
At present, most satellite images depict the earth’s surface. Points, distances, and angles on the satellite image have corresponding elements on the earth. This determines that satellite images have geodetic information which can be used by applications. Satellite image programming often requires some familiarity with the fundamentals of geodesy and cartography. Geodesy is the branch of applied mathematics that deals with measurements on the earth’s surface. Cartography is the study and development of maps and charts, usually of the earth’s surface. Many powerful program functions are based on this wealth of geographic and cartographic information. Applications can locate points defined by their geographical coordinates, determine the distance and azimuth between two points on an image, use the geo-coded data to find common references in several images, or associate a satellite image to a conventional digital map.
Gaussian Cloud Transformation
Published in Deyi Li, Yi Du, Artificial Intelligence with Uncertainty, 2017
Scale refers to the space or time unit of an object or phenomenon, a range of phenomena or processes in space and time, and the window used by people when they observe things, objects, patterns, or processes. In brief, scale is the description of the relative size of the object in the container. In different disciplines, the expression or meaning of scale is also different. In geomatics, cartography, and geography, scale is the ratio of the actual distance to its expression on the map. With the progress of life science and information technology, we now understand humans and nature at different scales, as shown in Figure 3.1. In Figure 3.1, objects being studied in particle physics involve a 10−15 m and 10−22 s physical scale of magnitude, while astrophysics has brought us to 1016 years magnitude, the, so-called, age of the universe. The two arrows facing each other tell us that understanding humans and nature at different scales may present an overall self-similarity. The relationship between intelligence and nature is much closer than ever before, so we need to understand intelligence at different scales and make sure that self-similarity actually exists.
Elements of Map Projections
Published in Terry A. Slocum, Robert B. McMaster, Fritz C. Kessler, Hugh H. Howard, Thematic Cartography and Geovisualization, 2022
Terry A. Slocum, Robert B. McMaster, Fritz C. Kessler, Hugh H. Howard
Although maps have numerous advantages over globes, they suffer from distortion, which is a natural consequence that results when Earth's two-dimensional curved surface is projected to a map—that is, when a map projection is created. The map projection is one of the most important concepts in cartography because the way in which Earth's two-dimensional curved surface is projected directly impacts the appearance of the graticule (lines of latitude and longitude in combination) and landmasses and, ultimately, the kinds of uses for which a map can be applied.
Accuracy evaluation of flood monitoring based on multiscale remote sensing for different landscapes
Published in Geomatics, Natural Hazards and Risk, 2019
Chao Yuan, Futao Wang, Shixin Wang, Yi Zhou
Different research fields define the term ‘scale’ in different ways. In ecology, the scale mainly refers to the amplitude (i.e. observation extent) and granularity (i.e. spatial resolution) (O'Neil 1998). In geography, scale primarily concerns space. However, the domains of temporal and thematic scale are also crucial (Mason 2001). Whether spatial, temporal, or thematic, the scale has several meanings in geography. The cartographic scale refers to the scale of a map. The geographic scale represents the geospatial extent of a study area. The operational scale represents the spatial extent of a particular geologic phenomenon. The measurement scale means the spatial resolution. (Quattrochi 1997; Quattrochi and Lam 2010). In this study, two scale aspects were considered: the spatial extent and spatial resolution.
Geographic scenario: a possible foundation for further development of virtual geographic environments
Published in International Journal of Digital Earth, 2018
Guonian Lü, Min Chen, Linwang Yuan, Liangchen Zhou, Yongning Wen, Mingguan Wu, Bin Hu, Zhaoyuan Yu, Songshan Yue, Yehua Sheng
Cartography is the study and practice of producing and using maps. Cartography adopts real geographic information and models it in maps to help humans understand where they are, how they are oriented, what objects are around them, etc. To date, methodologies such as projection, scaling, generalization, symbolic representation and visualization have been used in cartography to create different types of maps, from general to thematic, handmade to digital, and 2D to 3D. Modern cartography even constitutes many theoretical and practical foundations of GISs.