These remote sensors can be either passive or active. Passive sensors respond to external stimuli. Because of this, passive sensors can only be used to collect data during daylight hours. In contrast, active sensors use internal stimuli to collect data about Earth.
For example, a laser-beam remote sensing system projects a laser onto the surface of Earth and measures the time that it takes for the laser to reflect back to its sensor. GPS was originally intended for military applications, but in the s, the government made the system available for civilian use.
GPS works in any weather conditions, anywhere in the world, 24 hours a day. This GPS consists of three segments: the space segment, the control segment, and the user segment. The US Air Force develops, maintains, and operates the space and control segments. The space segment consists of a nominal constellation of 24 operating satellites that transmit one-way signals that give the current GPS satellite position and time. The control segment consists of worldwide monitor and control stations that maintain the satellites in their proper orbits through occasional command maneuvers, and adjust the satellite clocks.
It tracks the GPS satellites, uploads updated navigational data, and maintains health and status of the satellite constellation. Geospatial analysis is an approach to applying statistical analysis and other informational techniques to data which has a geographical or geospatial aspect. Such analysis would typically employ software capable of geospatial representation and processing, and apply analytical methods to terrestrial or geographic datasets, including the use of geographic information systems and geomatics.
Geospatial analysis, using GIS, was developed for problems in the environmental and life sciences, in particular ecology, geology, and epidemiology. It has extended to almost all industries including defense, intelligence, utilities, natural resources i.
Spatial statistics typically result primarily from observation rather than experimentation. January 2, Industry Trends. Overview Geospatial data is created, shared, and stored in many different formats. The two primary data types are raster and vector. Vector data is represented as either points, lines, or polygons.
Discrete or thematic data is best represented as vector. Data that has an exact location, or hard boundaries are typically shown as vector data. Examples are county boundaries, the location of roads and railroads using lines, or point data indicating the location of fire hydrants. By contrast, raster data is best suited for continuous data, or information that does not have hard boundaries or locations.
As rasters, the data are viewed as a series of grid cells where each cell has a value representing the feature being observed. Think of raster data as appropriate for modeling surfaces like elevation, temperature, precipitation, or soil Ph. These phenomena are measured at intervals think weather stations , and values in between are interpolated to create a continuous surface. Raster data also includes remote sensing imagery, like aerial photography and satellite imagery.
Vector Formats:. To have a complete shapefile, you must have at least 3 files with the same prefix name and with the following extensions:. Additionally, you may have a. All these files must be saved in the same workspace. GDB: Geodatabase The file geodatabase is a collection of geographic datasets of various types, with the most basic types being vector, raster, and tabular data. There are three types of geodatabases: file, personal, and ArcSDE.
It has largely been replaced by the geodatabase format. Coverages do not have an individual file extension. Instead it is composed of two folders within a "workspace" which each contain multiple files. One of the two folders carries the name of the coverage, and contains a number of various. The other folder is an "info" folder, which typically contains. E Arc Export or Interchange Format. Raster Formats:. Maguire and D. Rhind: In GIS Dictionary.
Federal Geographic Data Committee. Peters, D. Building a GIS : System architecture design strategies for managers 2nd ed. Thomas, C. What's your definition? Looking at what enterprise GIS really means. ArcUser Online 12 4 : Tomlinson, R. Thinking about GIS : Geographic information system planning for managers 3rd ed.
Fu, P. The Open Group Woodard, J. Electronic Thesis or Dissertation. Author and Citation Info:. No earlier editions exist. Topic Description:. Cloud : Someone else's computer. Defining Enterprise GIS Enterprise GIS is the implementation of GIS infrastructure, processes and tools at scale within the context of an organization, shaped by the prevailing information technology patterns of the day.
Consider the strategic purpose. Plan for the planning. Conduct a Technology seminar. Describe the information products. Define the system scope. Create a data design. Choose a logical data model. Determine system requirements. Benefit-cost, migration and risk analysis. Make an implementation plan. These capabilities are a function of system scale, sophistication, and interconnection, and they include, but are not limited to: 5.
Enterprise GIS Today While most of the material up until this point is written at a sufficient level of technical abstraction to remain relevant over time, a proper understanding of Enterprise GIS necessarily includes a discussion of its concrete realization as enabled by contemporary Information Technology tools and patterns.
Figure 1. The moving parts within a modern Enterprise GIS. Source: author. Learning Objectives:. Define Enterprise GIS in an generalized manner without reference to a specific enabling technologies. Explain the difference between a system and a process definition of Enterprise GIS. Describe the value-adding points of Enterprise GIS in an organizational setting. Express the importance of organizational context to the implementation and operation of an Enterprise GIS. Demonstrate the importance of iteratively evolving a given Enterprise GIS implementation over time.
Instructional Assessment Questions:. How does a services oriented architecture differ from a traditional client-server model, and how does this architectural pattern facilitate Enterprise GIS? Identify the key steps in an Enterprise GIS planning effort. What are some of the processes that go into the development of an Enterprise GIS?
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