Skip to main content

GIS Terminology 2





1. Geoid: A model representing the Earth's irregular shape due to variations in gravity and density, used as a reference surface for measuring elevations.

2. Geocoding: The process of converting an address or location description into geographic coordinates (latitude and longitude).

3. Geofencing: Defining virtual boundaries around a location to trigger actions or alerts when someone or something enters or exits the designated area.

4. Georeferencing: The process of aligning an image or map to a known coordinate system to establish its spatial reference.

5. Geoportal: A web-based platform that provides access to geospatial data, maps, and services from various sources.

6. Geoprocessing: A set of operations and tools used to manipulate and analyze geographic data in a GIS.

7. Geospatial Analysis: The process of examining geographic patterns, relationships, and trends within spatial data.

8. Global Navigation Satellite System (GNSS): A network of satellites that provide positioning, navigation, and timing services, including GPS.

9. GPS Accuracy: The degree of closeness between the measured GPS location and the actual location on the Earth's surface.

10. GPS Surveying: The use of GPS technology for precise positioning and data collection during surveying tasks.

11. Ground Truthing: Verifying and validating remotely sensed data using on-the-ground observations or field surveys.

12. Heatmap: A visual representation of data density, where colors indicate the intensity or frequency of occurrences in a geographic area.

13. Hyperspectral Imaging: Remote sensing technique that collects and analyzes detailed information from hundreds of narrow spectral bands.

14. Interpolation: A process of estimating values at unmeasured locations based on values at known locations.

15. Join: Merging data from two or more tables based on a common attribute field.

16. KML (Keyhole Markup Language): A file format used to display geographic data in applications like Google Earth.

17. Land Cover Classification: Categorizing the Earth's surface into different classes based on its physical and biological characteristics.

18. Latitude: Angular distance north or south of the equator, measured in degrees.

19. Lidar (Light Detection and Ranging): Remote sensing technology that uses laser pulses to measure distances and create 3D representations of the Earth's surface.

20. Line of Sight: A direct, unobstructed path between two points that can be used for visibility analysis.

21. Location-Based Services (LBS): Services that utilize location information to provide content or functionality to users based on their geographic position.

22. Longitude: Angular distance east or west of the prime meridian, measured in degrees.

23. Map Projection: A method used to represent the curved surface of the Earth on a flat map.

24. Map Scale: The ratio of distance on a map to the corresponding distance on the Earth's surface.

25. Multi-Criteria Decision Analysis (MCDA): A technique for evaluating multiple criteria to make decisions in GIS.

26. Near-Infrared (NIR): Electromagnetic spectrum region used in remote sensing for vegetation analysis and other applications.

27. Node: A point where two or more lines intersect in a network dataset.

28. Normalization: Scaling data to a common range, usually between 0 and 1, to remove bias during analysis.

29. Oblique Imagery: Aerial or satellite imagery taken at an angle, providing a different perspective from vertical imagery.

30. Orthophoto: An aerial photograph or satellite image that has been corrected for distortion and terrain relief.

31. Parcel Data: Information about individual land parcels, often used for property management and land administration.

32. Participatory GIS (PGIS): Involving local communities in the collection and analysis of geographic data to support decision-making.

33. Photogrammetry: The science of making measurements from photographs or images, often used for creating 3D models.

34. Point Data: Geospatial data represented as discrete, individual points with specific coordinates.

35. Polygon: A closed geometric shape with three or more sides, often used to represent areas on a map.

36. Proximity Analysis: Assessing relationships and distances between geographic features.

37. QuickBird: A commercial high-resolution satellite used for remote sensing applications.

38. Radiometric Resolution: The ability of a remote sensing sensor to distinguish variations in the electromagnetic radiation received from the Earth's surface.

39. Rectification: The process of aligning and transforming an image to remove geometric distortion.

40. Regression Analysis: A statistical technique used in GIS to identify relationships between variables.

41. Remote Sensing Platforms: Satellites, aircraft, or drones used to collect remote sensing data.

42. Resampling: Changing the resolution of raster data to match the desired output.

43. Reverse Geocoding: The process of converting geographic coordinates into human-readable addresses.

44. Routing: Finding the optimal path between two or more locations based on a network dataset.

45. Satellite Imagery: Images captured by satellites from space, used for various applications, such as environmental monitoring and land use analysis.

46. Sensor Fusion: Combining data from multiple sensors or sources to improve data quality and accuracy.

47. Spatial Autocorrelation: A statistical measure that evaluates the degree of spatial clustering or dispersion of data.

48. Spatial Data Infrastructure (SDI): The organizational, institutional, and technological framework for accessing and sharing spatial data.

49. Spatial Data Model: A conceptual representation of how geographic data is organized and structured in a GIS.

50. Spatial Join: A GIS operation that combines attributes from two spatially related datasets based on their spatial location.

51. Spatial Indexing: A technique used to speed up data retrieval and analysis in GIS by optimizing spatial queries.

52. Spatial Interpolation: The process of estimating values at unmeasured locations based on values at nearby measured locations.

53. Spatial Metadata: Information about the characteristics and source of spatial data.

54. Spatial Query: A method of retrieving data from a GIS based on spatial relationships or criteria.

55. Spatial Reference: A set of coordinates used to define the location of features in a GIS.

56. Spatial Resolution: The level of detail represented in a raster or image, typically measured in meters or feet.

57. Spatial-Temporal Analysis: Analyzing geographic data over time to identify patterns and trends.

58. Spectral Bands: Specific ranges of wavelengths in the electromagnetic spectrum used in remote sensing.

59. Spectral Signature: The unique reflectance or emittance pattern of a surface in the electromagnetic spectrum, used for land cover classification.

60. Standardization: The process of converting data to a consistent format or coordinate system for analysis.

61. Stream Network Analysis: Analyzing the flow of water in a river network using hydrologic tools.

62. Symbolization: Representing geographic data using various symbols, colors, and patterns on a map.

63. TIGER/Line: A dataset produced by the United States Census Bureau, providing detailed geographic data for mapping and analysis.

64. Tile-Based Rendering: A method used to display large-scale maps by dividing them into smaller tiles for efficient loading and rendering.

65. Time Series Analysis: Analyzing changes and patterns in geographic data over time.

66. Topographic Map: A detailed map representing natural and man-made features on the Earth's surface.

67. Topology: The spatial relationships and connectivity between geographic features.

68. UTM (Universal Transverse Mercator): A widely used map projection system that divides the world into zones for

 accurate mapping.

69. Vector Data: Geospatial data represented as points, lines, or polygons.

70. Vectorization: The process of converting raster data to vector data.

71. Web GIS: GIS applications and services accessible through web browsers.

72. WMS (Web Map Service): A standard protocol for serving and sharing map images over the internet.

73. WFS (Web Feature Service): A standard protocol for serving and sharing geospatial features over the internet.

74. WMTS (Web Map Tile Service): A standard protocol for serving pre-rendered map tiles over the internet.

75. WKT (Well-Known Text): A text representation of geometric objects in a GIS.

76. WKB (Well-Known Binary): A binary representation of geometric objects in a GIS.

77. Zoom Level: The level of detail shown on a map, determined by the scale or resolution.

78. 3D GIS: A GIS that incorporates three-dimensional data, enabling visualization and analysis in a vertical dimension.

79. 3D Modeling: Creating three-dimensional representations of geographic features or landscapes.

80. 3D Visualization: Displaying and exploring geospatial data in three-dimensional space.

81. 4D GIS: A GIS that includes time as the fourth dimension, enabling temporal analysis.

82. Agent-Based Modeling (ABM): A simulation technique used to model individual entities and their interactions in a geographic environment.

83. Augmented Reality (AR): Overlapping computer-generated information onto a real-world view, often using mobile devices or wearable technology.

84. Bounding Box: The minimum rectangular area that encompasses a set of geographic features or an image.

85. Buffer Analysis: Creating a buffer zone around a geographic feature based on a specified distance.

86. Catchment Area: The area from which water drains to a specific point, such as a river or a lake.

87. Change Detection: Identifying and analyzing differences between multiple datasets taken at different times.

88. Cluster Analysis: Identifying groups of similar features based on their spatial proximity and attribute similarities.

89. Conflation: Merging multiple datasets with similar features to create a more accurate and complete dataset.

90. Crowdsourcing: Gathering geospatial data and information from the public through online platforms or mobile applications.

91. Density Mapping: Creating maps that represent the concentration of points or events in specific geographic areas.

92. Digital Elevation Model (DEM): A digital representation of the Earth's terrain, typically represented as a grid of elevation values.

93. Dissolve: Combining adjacent polygons with the same attribute value into a single, larger polygon.

94. Edge Matching: Aligning adjacent map sheets to ensure a seamless representation of data.

95. Fractal Analysis: Studying the self-similarity and complexity of geographic patterns using fractal geometry.

96. Fuzzy Logic: A mathematical approach that allows for uncertainty and imprecision in spatial analysis.

97. Geoanalytics: The use of advanced statistical and analytical techniques in GIS to extract insights from spatial data.

98. GeoJSON: A data format used to represent geographical features in JSON (JavaScript Object Notation) format.

99. Geoportal: A web-based platform that provides access to geospatial data and services.

100. Geospatial Big Data: Large volumes of geographically referenced data generated from various sources like sensors, mobile devices, and social media.

I hope you find this extended list of GIS terminologies helpful! If you have any more questions or need further explanations, please don't hesitate to ask.

Comments

Popular posts from this blog

Photogrammetry – Types of Photographs

In photogrammetry, aerial photographs are categorized based on camera orientation , coverage , and spectral sensitivity . Below is a breakdown of the major types: 1️⃣ Based on Camera Axis Orientation Type Description Key Feature Vertical Photo Taken with the camera axis pointing directly downward (within 3° of vertical). Used for maps and measurements Oblique Photo Taken with the camera axis tilted away from vertical. Covers more area but with distortions Low Oblique: Horizon not visible High Oblique: Horizon visible 2️⃣ Based on Number of Photos Taken Type Description Single Photo One image taken of an area Stereoscopic Pair Two overlapping photos for 3D viewing and depth analysis Strip or Mosaic Series of overlapping photos covering a long area, useful in mapping large regions 3️⃣ Based on Spectral Sensitivity Type Description Application Panchromatic Captures images in black and white General mapping Infrared (IR) Sensitive to infrared radiation Veget...

Photogrammetry – Geometry of a Vertical Photograph

Photogrammetry is the science of making measurements from photographs, especially for mapping and surveying. When the camera axis is perpendicular (vertical) to the ground, the photo is called a vertical photograph , and its geometry is central to accurate mapping.  Elements of Vertical Photo Geometry In a vertical aerial photograph , the geometry is governed by the central projection principle. Here's how it works: 1. Principal Point (P) The point on the photo where the optical axis of the camera intersects the photo plane. It's the geometric center of the photo. 2. Nadir Point (N) The point on the ground directly below the camera at the time of exposure. Ideally, in a perfect vertical photo, the nadir and principal point coincide. 3. Photo Center (C) Usually coincides with the principal point in a vertical photo. 4. Ground Coordinates (X, Y, Z) Real-world (map) coordinates of objects photographed. 5. Flying Height (H) He...

Raster Data Structure

Raster Data Raster data is like a digital photo made up of small squares called cells or pixels . Each cell shows something about that spot — like how high it is (elevation), how hot it is (temperature), or what kind of land it is (forest, water, etc.). Think of it like a graph paper where each box is colored to show what's there. Key Points What's in the cell? Each cell stores information — for example, "water" or "forest." Where is the cell? The cell's location comes from its place in the grid (like row 3, column 5). We don't need to store its exact coordinates. How Do We Decide a Cell's Value? Sometimes, one cell covers more than one thing (like part forest and part water). To choose one value , we can: Center Point: Use whatever feature is in the middle. Most Area: Use the feature that takes up the most space in the cell. Most Important: Use the most important feature (like a road or well), even if it...

Photogrammetry

Photogrammetry is the science of taking measurements from photographs —especially to create maps, models, or 3D images of objects, land, or buildings. Imagine you take two pictures of a mountain from slightly different angles. Photogrammetry uses those photos to figure out the shape, size, and position of the mountain—just like our eyes do when we see in 3D! Concepts and Terminologies 1. Photograph A picture captured by a camera , either from the ground (terrestrial) or from above (aerial or drone). 2. Stereo Pair Two overlapping photos taken from different angles. When seen together, they help create a 3D effect —just like how two human eyes work. 3. Overlap To get a 3D model, photos must overlap each other: Forward overlap : Between two photos in a flight line (usually 60–70%) Side overlap : Between adjacent flight lines (usually 30–40%) 4. Scale The ratio of the photo size to real-world size. Example: A 1:10,000 scale photo means 1 cm on the photo...

Logical Data Model in GIS

In GIS, a logical data model defines how data is structured and interrelated—independent of how it is physically stored or implemented. It serves as a blueprint for designing databases, focusing on the organization of entities, their attributes, and relationships, without tying them to a specific database technology. Key Features Abstraction : The logical model operates at an abstract level, emphasizing the conceptual structure of data rather than the technical details of storage or implementation. Entity-Attribute Relationships : It identifies key entities (objects or concepts) and their attributes (properties), as well as the logical relationships between them. Business Rules : Business logic is embedded in the model to enforce rules, constraints, and conditions that ensure data consistency and accuracy. Technology Independence : The logical model is platform-agnostic—it is not tied to any specific database system or storage format. Visual Representat...