Vector data are spatial object representations with associated features (attributes/variables).
Vector data models:
ESRI Shapefile and implementations of Simple Features are non-topological vector formats.
A GeoJSON feature is an object of
"type": "Feature" with
geometry and additional
FeatureCollection object is a set of features.
GeoJSON supports the following geometry
type specified with
Point: a single position, specified as an ordered array
[longitude, latitude, height];
LineString: an array of positions;
Polygon: a collection of LinearRing (loops of positions) specifying exterior (counterclockwise) and interior (clockwise) boundaries;
GeometryCollectionis a container for different kinds of geometries.
An awesome list of GeoJSON utilities compiled by Tom MacWright.
WKT (Well Known Text) Representation (of Simple Features 1.2 geometries):
POINT(- 117.25 35.0)
LINESTRING(0 10, 20 15, 30 15)
POLYGON((0 0,10 10,10 0,0 0),(3 1,4 1,4 2,3 1))
POLYHEDRALSURFACE(((0 10,0 0,10 0,10 10,0 10)),((0 10,5 15, 10 10,0 10)))
MULTIPOINT((0 0),(10 10),(10 0))
MULTILINESTRING((0 0,10 10,10 0),(3 1,4 1,4 2,5 1))
MULTIPOLYGON(((0 0,10 10,10 0,0 0),(3 1,4 1,4 2, 3 1)),((20 20, 30 30, 30 20, 20 20)))
GML (Geography Markup Language) is an OGC Standard, defined as an XML schema (written in XSD). GML profiles are restricted subsets of the full GML standard, such as GML Point Profile, GML Simple Features profile, and GML in JPEG 2000. GML application schemas are domain or community specific extensions of GML, with extra GML-defined XML vocabulary in a new namespace, such as CityGML, SensorML, Coverages.
GML has a very broad schema set:
Feature, Coordinate reference system, Geometry; Topology; Coverage (including geographic images), Unit of measure, Observations; Directions; Time, Dynamic feature; Map presentation styling rules.
An example file snippet in GML Simple Features:
<gml:Point gml:id="p1" srsName="http://www.opengis.net/def/crs/EPSG/0/4326"> <gml:coordinates>45.67,88.56</gml:coordinates> </gml:Point> <gml:LineString gml:id="l1" srsName="http://www.opengis.net/def/crs/EPSG/0/4326"> <gml:coordinates>45.67,88.56 55.56,89.44</gml:coordinates> </gml:LineString> <gml:Polygon> <gml:outerBoundaryIs> <gml:LinearRing> <gml:coordinates>0,0 100,0 100,100 0,100 0,0</gml:coordinates> </gml:LinearRing> </gml:outerBoundaryIs> </gml:Polygon>
GPX (GPS Exchange Format) is an XML schema describing:
wptType): recorded locations;
trkType): one ordered list of waypoints for each continuous span of GPS connection;
rteType): an ordered list of routepoints, which represent significant turns or stage points for trip planning.
Latitude and longitude are expressed in decimal degrees using the WGS 84 datum. Elevation is recorded in meters. Dates and times are in Coordinated Universal Time (UTC) using ISO 8601 format.
allows topology, curve
ESRI File Geodatabase is a directory with
.gdb extension, which contains files with extensions
.atx, attribute index;
.spx, spatial index.
The FileGDB driver can read and write file geodatabases created by ArcGIS 10 and above,
but relies on the proprietary FileGDB API SDK.
The OpenFileGDB driver can read from, but not write to, file geodatabases created by ArcGIS 9 and above.
ESRI Personal GeoDatabase is a Microsoft Access database (
with a set of tables defined by ESRI for holding geodatabase metadata,
and with geometry for features held in a BLOB column in a custom format.
Raster data are observations embedded in a regular geospatial grid.
Raster data file formats:
TIFF (Tagged Image File Format) was developed by Aldus in 1986, now Adobe Systems.
GeoTIFF is a public domain metadata standard developed in NASA JPL in 2000,
which specifies TIFF tags for georeferencing information
such as map projection, coordinate system, ellipsoid, and datum.
GeoTIFF accepts a world file with extension
.tfw (PNG with
a six-line text file specifying a 2D affine transformation (location, scale, and rotation).
When a GeoTIFF file is opened in read-only mode,
the driver may build a
.ovr external overview (down-sampled presentation).
Mapbox Studio can render TIFF files as tilesets.
IMG, Erdas Imagine file format; with overview in reduced resolution dataset (RRD) format.
GRID, ARC/INFO GRID, a proprietary multi-directory binary format by ESRI;
Aerial photogrammetry (such as orthoimagery) and satellite imagery are spatially referenced. Example data sets include land cover.
Point clouds are 3D point data collected from laser scanning (LiDAR).
NetCDF (Network Common Data Form) supports array-oriented scientific data, specifically digital geospatial information representing space and time-varying phenomena. NetCDF Climate and Forecast (CF) Metadata Conventions
HDF (Hierarchical Data Format) is a multi-object file format for storing and transferring graphical and numerical data mainly used in scientific computing. HDF supports several data models: multidimensional arrays, raster images, and tables.
OpenCV (Open Computer Vision) provides low level portable data types and operators, and a set of high level functionalities for video acquisition, image processing and analysis, structural analysis, motion analysis and object tracking, object recognition, camera calibration and 3D reconstruction.
KML Language Reference defines annotation of maps and images, presentation of graphical data on the globe (3D models, photo overlay), and camera movement.
KML is native to Google Earth, where you can create and display KML files.
KML text files (
.kml) and related images can be archived into a ZIP file (
Besides Google Earth, KML files can be displayed in ESRI ArcGIS, Adobe PhotoShop, Autodesk AutoCAD, and NASA World Wind.