Glossary of simple spatial terms
Arc:
Any unbroken part of the circumference of an ellipse.
Arc_Z:
Any unbroken part of the circumference of an ellipse in 3D.
Blob:
A database field that holds any digitized information, including text, images, audio or video. Also known simply as a "large object" or LOB, a BLOB may have a huge storage capacity. Binary Large Object
Bounding Box:
This is a User Defined Type that is used to describe a 3D axis aligned box area.
Box3D:
A Box3D is an object like a box, and you can specify the point from which the box takes shape. You need a starting point and vectors along the x, y and z axis.
Cap:
A cap is part of the surface of a sphere which extends from the top of a sphere down a fixed angle of latitude.
Cone:
The cone object allows construction of elliptical cones or cylinders.
Disc:
A Disc is a disc like object that has a X axis vector, a Y axis vector and a center point.
Dimension:
The minimum coordinate space required to represent an object without loosing information. Examples: for a point the dimension is 0; for a linestring, the dimension is 1; for squares or circles or polygons etc, the dimension is 2; for box3D etc the dimension is 3.
2-dimensional renderings (ie. flat drawings) of a 0-dimensional point, a 1-dimensional line segment, a 2-dimensional square, a 3-dimensional cube
Dynamic Load:
Dynamic Load Layers are layers which automatically just reload enough data to display their current visible view. This option is used to display data sets which would otherwise be too large to view. There is a Dynamic Load Factor in the Settings Dialog of the SpatialXL Graphics functions which specifies the factor as a fraction representing a percentage (0.4 would be 40%) of the additional amount of spatial data which should be loaded around the edges of the dynamic load to make panning smoother.
Ellipse:
A closed, symmetric curve shaped like an oval. The sum of the distances of any point on an ellipse from two fixed points remains constant no matter where the point is on the curve.
ESRI:
ESRI was founded as the Environmental Systems Research Institute in 1969 as a privately held consulting firm that specialized in land use analysis projects. The worldwide headquarters of ESRI are anchored in a multicampus environment in Redlands, California. ESRI is a world leader in the Geographic Information System (GIS) software industry. Their business involves the development and support of GIS software.
Geometry:
1. The shape or form of a surface or solid.
2. The mathematics of the properties, measurement, and relationships of points, lines, angles, surfaces, and solids.
3. A geometry restricted to a class of problems or objects: solid geometry.
GeometryCollection:
A GeometryCollection is a geometric object that is as collection of 1 or more geometric objects. It is an unrestricted geometric collection, in the sense that it is not restricted to inherit from a specific geometric type, but can contain any types.
GeometryType:
Type of Geometry as listed in the Type Codes, for instance, linestring or multipolygon or line or point etc.
GIS:
A geographic information system (GIS), or geographical information system captures, stores, analyzes, manages, and presents data that is linked to location.
In the strictest sense, the term describes any information system that integrates, stores, edits, analyzes, shares, and displays geographic information. In a more generic sense, GIS applications are tools that allow users to create interactive queries (user created searches), analyze spatial information, edit data, maps, and present the results of all these operations. Geographic information science is the science underlying the geographic concepts, applications and systems, taught in degree and GIS Certificate programs at many universities.
Hull:
The husk, shell, or outer covering. Any covering or envelope.
LineString:
A LineString is a Curve with linear interpolation between a given sequence of Points. Each consecutive pair of Points defines a line segment.
Linestring_Z:
A Linestring_Z is a curve with linear interpolation between a given sequence of 3D Points. Each consecutive pair of Points defines a line segment.
Meridian:
Imaginary line on the Earth's surface from the North Pole to the South Pole
MultiLineString:
A MultiLineString is a GeometryCollection whose elements are LineStrings.
MultiLinestring_Z:
A MultiLinestring_Z is a GeometryCollection whose elements are LineString3Ds.
MultiPoint:
A MultiPoint is a 0-dimensional GeometryCollection. The elements of a MultiPoint are restricted to Points. The points are not connected or ordered.
MultiPoint_Z:
A MultiPoint_Z is a 0-dimensional GeometryCollection. The elements of a MultiPoint_Z are restricted to 3D Points. The points are not connected or ordered.
MultiPolygon:
A MultiPolygon is a GeometryCollection whose elements are Polygons.
MultiSurface:
A MultiSurface is a 2-dimensional GeometryCollection whose elements are Surfaces. The interiors of any two surfaces in a MultiSurface may not intersect. The boundaries of any two elements in a MultiSurface may intersect, at most, at a finite number of Points. MultiSurface is a non-instantiable class. It defines a set of methods for its subclasses.
MultiSurface3D:
A MultiSurface3D is a 3-dimensional GeometryCollection whose elements are restricted to Surface_Z derived objects. The interiors of any two surfaces in a MultiSurface3D may not intersect. The boundaries of any two elements in a MultiSurface3D may intersect, at most, at a finite number of Points. MultiSurface3D is a non-instantiable class. It defines a set of methods for its subclasses. This class is created for future use.
Polygon:
A Polygon is a planar surface defined by 1 exterior boundary and 0 or more interior boundaries. Each interior boundary defines a hole in the polygon.
Open Geospatial Consortium:
The Open Geospatial Consortium, or OGC (www.opengeospatial.org), is an international voluntary consensus standards organization. In the OGC, more than 330+ commercial, governmental, nonprofit and research organizations worldwide, collaborate in an open consensus process encouraging development and implementation of standards for geospatial content and services.
Point:
Geometric Object that represents a location in 2 dimensional space. A 0-dimensional geometric object that represents a single location in coordinate space. A point has an x-coordinate and a y-coordinate value.
Point_Z:
A 3D point is a 0-dimensional geometric object (see dimension) and represents a single location in coordinate space. A 3D point has an x-coordinate, a y-coordinate and a z-coordinate value.
Polygon:
In geometry a polygon traditionally a figure that is bounded by a closed path or circuit, composed of a finite sequence of straight line segments. These segments are called its edges or sides, and the points where two edges meet are the polygon's vertices or corners. The interior of the polygon is sometimes called its body.
Raster:
In computer graphics a raster graphics image or bitmap is a data structure representing a generally rectangular grid of pixels, or points of colour, viewable via a monitor, paper, or other display medium. Raster images are stored in image files with varying formats, such as jpeg, bmp, tiff etc.
Scale:
To scale an object is to enlarge or diminish an object depending on the ratio.
Shapefile:
In this documentation, refers to a filename with the extension .SHP that stores geometric data. This file uses the binary formats as specified by ESRI. Shapefiles ususally come in tandem with a .DBF file, which stores non-geometric data. So usually when referring to a shapefile, we are referring to its associated DBF file as well. Note that the DBF file has the same name as the Shapefile, only the extension changes.
Spheroid:
A Spheroid is a closed surface that has a sphere-like shape.
SRID:
Spatial Reference System ID: It refers to the spatial reference system which is the coordinate transformation, the units, and meridian information that specify the spatial reference system. Spatial Reference System IDentifier.
Surface:
A Surface is a 2 dimensional geometric object. A simple surface consists of a single patch that is associated with one exterior boundary and 0 or more interior boundaries. A subtype of surface is Polygon.
Surface_Z:
A Surface_Z is a 2 dimensional geometric object in 3D space. A simple Surface_Z consists of a single patch that is associated with one exterior boundary and 0 or more interior boundaries. A subtype of Surface_Z is Tin_Z.
Text3D:
Text3D is solid 3D text.
Transform:
to change in form, appearance, or structure
Translation:
A translation is the motion of an object in which every point of the object moves parallel to and the same distance as every other point of the object.
Transpose:
(Of a matrix) to interchange rows and columns.
Triangulated Surface:
A Triangulated Surface is a 3D surface described by triangles. If the surface is closed, the surface describes the contained volume.
Well Known Binary Format:
Standard binary representation of Geometric objects, which leads to easy transfer of objects from one system to another sytem. Very compact specification of data and in machine readable format. In the 2D arena this is regulated by the Open Geospatial Consortium.
Well Known Text Format (WKT)
Well-known text (WKT) is a text markup language for representing vector geometry objects on a map, spatial reference systems of spatial objects and transformations between spatial reference systems. A binary equivalent, known as well-known binary (WKB) is used to transfer and store the same information on databases, such as Microsoft SQL Server 2008. The formats are regulated by the Open Geospatial Consortium (OGC) and described in their Simple Feature Access and Coordinate Transformation Service specifications. In other words, this textual representation of lines, points and polygons is a standard developed by the OGC and used in Spatial Databases and of course, SpatialXL, to represent Geometries. When loading from Excel, you either have to load X, Y or X, Y and Z points or - if loading geometry data - ensure that these are represented in this standard.
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