grid - [cartography]
(1) In cartography, any network of parallel and perpendicular lines superimposed on a map and used for reference. These grids are usually referred to by the map projection or coordinate system they represent, such as universal transverse Mercator grid. (2) See raster ...
A grid system allows the location of a point on a map (or on the surface of the earth) to be described in a way that is meaningful and universally understood.
A discretely uniform unit that represents a portion of the Earth. such as a square meter or square mile. Each grid cell has a value that corresponds to the feature or characteristic at that site, such as a soil type, census tract, or vegetation class. See also Cell.
[ESRI software] A mechanism for storing multivariate raster data in ESRI software, consisting of an ordered set of spatially overlapping grids (referred to as layers) referenced by an INFO file or geodatabase. A stack is treated as a single entity for multivariate analysis.
Grid-based map analysis is increasingly used to characterize conditions and impacts of infrastructure networks, such as pipe and power lines.
~ Generation and GIS
~ generation is a broad field with applications in aerodynamics, material science, biology, earth science, chemistry and physics, for example.
~ templates available with the installation
A number of ~ templates are delivered with ArcGIS and are located under the ArcGIS installation directory (\ArcGIS\Desktop10.1\GridTemplates).
About ~ Data Files for Australia and New Zealand
AutoCAD Map 3D comes with ~ data files for Australia and New Zealand.
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The ~ drawing may be turned off by using the -n flag.
The border drawing may be turned off by using the -b flag.
The coordinate text may be turned off by using the -t flag.
Using a UTM ~ overlay tool
If you want to find your location with more precision than is available from the ~ lines on the map, you will need a tool that is marked in finer divisions. One such tool is a ~ overlay.
~ layers are graphical representations of the ArcGIS and ArcInfo implementation of the raster data model. ~ layers are stored with a numeric value for each cell. The numeric cell values are either integer or floating-point.
GIS data layer in raster format (cell-based representation)
~ Snaps: It is difficult to put your mouse exactly on (90,90,0) isn't it? Right now, our drawing has a resolution down to the inch. Our life would be simpler if we could make out mouse snap to even increments of 10 feet. This is accomplished with the use of ~ snaps.
~ -- (1) a set of ~ cells forming a regular, or nearly regular, tessellation of a surface; (2) a set of points arrayed in a pattern that forms a regular, or nearly regular, tessellation of a surface.
A pattern of regularly spaced horizontal and vertical lines forming square zones on a map used as a reference for establishing points. ~ examples are UTM, MGRS, and Maidenhead.
Project managers must be mindful of the transition from in-program mapped units to real-world locations.
~: A geographic data model representing information as an array of equally sized square cells arranged in rows and columns. Each ~ cell is referenced by its geographic x,y location.
GRIDA fully integrated ~(cell-based) geoprocessing system for use with ARC/INFO. ~ supports a Map Algebra spatial language that allows sophisticated spatial modeling and analysis.
~ and Map Overlays
Silva Navimap -- electronic map reading / overlay device
U.K.: Yeoman PLC's Navigator Pro is a plotting table with GPS inputs that works with Admiralty charts. Quite impressive.
The ~ represents lines having constant rectangular coordinates (x, y). The ~ is almost always a rectangular system and is used on large and medium scale maps to enable detailed calculations and positioning.
4 ~ references
Store ~ references in an appropriate notation for easy transition to a GIS or conversion to an appropriate map projection (e.g.
The UTM ~
The best known use of the transverse Mercator projection is the specialized form called Universal Transverse Mercator (UTM) projection system.
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â†' Distinguishing Cloud Computing from Utility Computing ...
Attributes Coded with Image
Other Forms of Coding
Image and Attribute Distinction
The graphic side of a map is the lines and descriptors. Examples of these lines are rivers or roads.
~ data sets come from many sources: remote sensing devices, converted topographic maps, interpolated point data, conversion from vector features, and derived from other features (through distance, proximity, and density calculations, for instance).
~ placement tools for ceiling mounted equipment
Bi-directional Lighting Analysis interface to Visual Pro in design mode ...
~ Cell Map
Map displaying spatial information in the form of color coded, equal sized rectangle, squares, equilateral triangles or hexagons. The color of the cell determined by the condition assigned to the cell according to a uniformly applied rule regarding the condition (i.e.
A network of uniformly spaced horizontal and vertical lines employed to allow an exact reference to any point on a map. A ~ pattern does not necessarily correspond with recognized lines of latitude and longitude, especially when dealing with relatively large-scale maps.
~ Cell - An element of a raster data structure (see raster).
GUI - See Graphical User Interface.
~ Referenced Information Display System; Gridded Resource Inventory Data System
Geodetic Reference System ...
The ~-zone designation.
The 100,000-meter-square letter identification.
The ~ coordinates (also referred to as rectangular coordinates) of the numerical portion of the reference, expressed to a desired refinement.
tax ~, roads, major utility lines, schools, churches, recreation centers, county boundary
watersheds, WSSC ~, roads, major utility lines, schools, churches, recreation centers, county boundary ...
e.g. ~ cells covering large areas
historically, natural resource GIS have been raster-based
adequate for many planning and management applications
can provide comprehensive coverage of a jurisdiction at reasonable cost
could often run on existing mainframes - hardware requirements were modest ...
7. 3D ~ file creation and real time 3D display of the generated vector data. Animate the 3D display at any angle specified and see the vector data in a brand new way.
8. Implemented import function for AutoCAD DXF, MapInfo MIF/MID and ArcView Shape file.
Such a ~ can be placed anywhere on a map and used to assign locations to points on the map.
T-in-O maps ...
For the ~, under the Axes and Labels tabs in the Reference System Properties make all the lines, accept the meridians and parallels, invisible and make the labels invisible as well (change their color to "No Color" in the color symbology window).
UTM Map ~ and the Australian Map ~
As is explained in the section tiled Explaining Some Jargon - Graticules and Grids there is a significant difference between the two. This is ...
Military ~ Reference System
Maine Geological Survey; Maryland Geological Survey; Minnesota Geological Survey; Mars Global Surveyor (satellite) ...
Creating a ~ across the view can help to better reference the view. This can be especially important when printing out a map for later use.
After initialization the user is presented with a world map showing the currently defined Loran-C transmitters. Using zoom tools the user selects an area for coverage prediction. When DoMap is activated a ~ of points is produced by the MAKEGRID module.
in a regular ~ of values, one for each cell,
a regular lattice of points or
a 'triangulated irregular network' (TIN) of points.
Digital Exchange Format (DXF)
ASCII text files defined by Autodesk, Inc. Originally used in CAD, now showing up in a third party GIS software.
See the Universal Transverse Mercator (UTM) ~ System. Recumbent Fold A fold in which the axial plane is almost horizontal. Recurrence Interval The average time period that separates natural events of a specific magnitude.
Graticule - The ~ of latitudes and longitudes drawn on a map or a globe.
GRS80 (Geodetic Reference System of 1980) - A standard defining the size and shape of the Earth as adopted by the International Union of Geodesy and Geophysics in 1979.
National ~ is a point coordinate representation using a single alphanumeric coordinate (for example, 18SUJ2348316806479498). This approach contrasts with the use of numeric coordinates to represent the location of a point, as is done with Oracle Spatial and EPSG. A good description of the U.S.
41 a framework for recording spot elevations in a regular rectangular ~ (matrix); an acronym originally created from Digital Elevation Model at US Geological Survey. To avoid ambiguity, DEM will be used exclusively for a ~ framework, so it can be read matrix. derived measurement p.
A GIS database includes data about the spatial location and shape of geographic features recorded as points, lines, areas, pixels, ~ cells, or tins, as well as their attributes. database design The formal process of analyzing facts about the real world into a structured database model.
Geocoding: The cross-referencing between specifically recorded x,y co-ordinates of a location, relative to a standard reference ~ such as the NC State Plane ~, and non-geographic data such as addresses or Zip codes.
point to ~ interpolation Source: GETIS glossary The conversion from a geospatial data set that represents a surface with points and their attributes (e.g. terrain heights) to a ~ (raster) data structure that represents the same surface.
The ~ is defined by identifying one of its corners (lower left usually), the distance between nodes in both the X and Y directions, the number of nodes in both the X and Y directions, and the ~ orientation.
Recorded x, y coordinates of a location are cross-referencing between a standard reference ~ and non-geographic data such as addresses or zip codes to accurately map that location. In order to geocode, a geocoding service must first be defined.
For example if we want to deliver the data in a regular ~, but the samples are measured in scattered points we have to calculate the values of ~ points from the samples using interpolation procedures.
In the phase of analysis we face an other problem.
For example an aerial photograph may need to be stretched (orthorectified) using photogrammetry so that its pixels align with longitude and latitude gradations (or whatever ~ is needed).
This system is broken down into ~ zones. For states extending predominantly east-west, this system uses the Lambert conformal conic projection. For states extending predominantly north-south, the transverse cylindrical Mercator projection was adopted.
The first is called "Calculations involved in preparing a ~ of graticule" and is heavily math oriented, containing formulas for several projections. The second section is concerned with accurately drawing a graticule manually.
As described in Chapter 1, the raster data model aligns the Earth's surface into a ~ of columns and rows.
The program will prompt you for the ~ spacing, a corner tie point, and the UTM zone. (Since ASTER images all seem to be oriented north and south, GEOTIFF only requires one tie point.) This data is available in the metadata (.met) file.
a corresponding system of imaginary lines on an adopted terrestrial or celestial datum surface. Also, the mathematical concept for such a system. For maps of the Earth, a projection consists of 1) a graticule of lines representing parallels of latitude and meridians of longitude or 2) a ~.
Raster references spatial data according to a ~ of cells (or pixels), whereas vector data references spatial data to a series of coordinates. Raster data consist of different numerical values assigned to individual pixels.
The procedure for locating and translating geographic coordinates in x,y digits or ~ cells for an object or event in space and coded in map units, lines, and points.
Not many people know the National ~ coordinates of where they live so any list of people's addresses needs to be geocoded to load it into a GIS.
Cell data are arranged in a regular ~ pattern in which each unit (or cell) in the ~ is assigned an identifying value based on its characteristics. Information obtained from image sources such as remote sensing from photography and satellite.
The Raster data model is the simpler of the two and is based on the division of reality into a regular ~ of identically shaped cells. Each cell is assigned a single value which represents the attribute for the area of that cell.
From the View Button bar, click on the Open Table Button (looks like a sheet of paper with a ~ on it).
Resize the "Attributes of County Boundaries" Table.
Scroll down the list of records until you see a single selected record (remember - yellow means selected).
Geographic References: Geographic information contains either an explicit geographic reference, such as a latitude and longitude or national ~ coordinate, or an implicit reference such as an address, postal code, census tract name, forest stand identifier, or road name.
x coverage or ~. If you receive ARC/INFO data in interchange format you can use IMPORT71 to convert it to a data source in a format that can be added to a project or view in ArcView (or used in other mapping programs).(Source: ArcView 3.2 help) If you have ArcView GIS you already have IMPORT71...
Smooth surface technique: A way of representing data in a raster (~) format when multiple features would otherwise be layered upon one another at a single point. The data is added together, averaged and distributed over adjoining squares.
In raster format, a ~ is used to represent the study area. The location of features in the study area is depicted by the values in the cells overlaying the feature. Vector data represent geographic features by coordinates of points, lines, and polygons.
The calculation of curvature uses the second order derivative for the 3x3 ~ of pixels.
Ground control refers to points on the surface of the earth with known coordinates as represented by some geographic ~ reference system.
Yes - 4 level Multi-Level ~ hierarchy (BOL says its B-Tree based) with tessalation as described Isaac Kunen Multi-Level ~ requires defining an index ~ for optimal performance
R-Tree quadratic splitting - indexes only exist for MyISAM
GIST - a variant of R-Tree ...
A pattern of bits on a ~ used to generate an image.
Bits Per Inch (BPI)
The density of bits recorded on a magnetic tape; e.g. 800, 1600, and 6500 are common standards. It is in fact equivalent to bytes per inch on a tape since a byte is stored lengthwise across the tape.
For example, using a special type of aerial photo showing vegetation, you can make a ~ of squares that show the primary vegetation type for each cell. The cells might be 10x10 meters or as big as 100 meters square.
Raster Data: One method of storing, representing or displaying spatial data in digital form. It consists of using cell data (not necessarily square) arranged in a regular ~ pattern in which each unit (pixel or cell) within the ~ is assigned an identifying value based on its characteristics ...
Resampling - Extrapolating pixels values for a new ~ from values in an old ~. It is applied after an image is rectified to a projection system or registered to another image (TWS) ...
The position information in a Magellan GPS receiver may be displayed as longitudeAatitude, Universal Transverse Mercator, Military ~ or other system coordinates.
Bill Meehan answers Is the Smart ~ Smart? [PODCAST]
Lori Armstrong details What's New in Water/Wastewater GIS [VIDEO]
See how Mobile GIS provides real-time situational awareness [VIDEO] ...
OGC ~ Coverage representation of raster information
OGC Filter and Common Constraint Language (CQL)
Clients for Web Feature Service (WFS), Web Map Service (WMS) and experimental support for Web Process Service (WPS)
ISO 19107 Geometry ...
E00 - Is ArcInfo's interchange format. It is used to enable a coverage, ~, TIN and associated INFO tables to be transferred between different machines. (ESRI website - March 2010) ...
* In order to save time, and maintain accuracy, the proceedure is to use the same coordinate ~ system as the base map or GPS system used in the collection of ground control points.
For centuries, both Greek and Chinese scientists attempted several different methods but a reliable one did not develop until the ancient Greek geographer, astronomer and mathematician, Ptolemy, created a ~ system for the Earth. To do this, he divided a circle into 360°.
Now the cylinder's axis passes through the equator, and it can be rotated to line up with the area of interest. Many countries and US states use Transverse Mercator for their ~ systems, especially countries such as New Zealand, which are long N/S and narrow E/W.
The procedure usually differs minimally from vector based software digitizing, other than some raster systems allow the user to define the resolution size of the ~-cell. Conversion to the raster structure may occur on-the-fly or afterwards as a separate conversion process.
A logical collection of interrelated information, managed and stored as a unit, usually on some form of mass-storage system such as magnetic tape or disk. A GIS database includes data about the spatial location and shape of geographic features recorded as points, lines, areas, pixels, ~ cells, ...
KML - Keyhole markup language-a file type storing ~ coordinates and attributes, and how to render them.
KMZ - A compressed or “zipped' version of a kml file.
Due to the laws of the universe, each type of projection must make tradeoffs on how and what features it distorts. Raster A raster is a rectangular ~ of pixels. Essentially an image.
A projected coordinate system which defines a location on earth relative to a 60-zone ~ system. Locations are defined relative to the WGS84 reference ellipsoid. With a couple of exceptions, zones cover 6° longitude and 8° latitude.
These "patent surveys", recorded at the Texas General Land Office, constitute an official land ~ for the State and are the basis for subsequent land surveys.
The digital elevation model, consisting of surface elevations recorded on a 30-meter horizontal ~, shows high elevations as white and low elevation as black.
See also: What is the meaning of Information, Map, Location, Geographic, Feature?