Formats

US Land Grid provides our data in multiple file formats and web mapping streams.

• Shapefile - Esri's open, hybrid vector data format using SHP, SHX and DBF files
• File Geodatabase - Esri's file-based geodatabase format, stored as folders in a file system
• CDF file - Native file format used for GeoGraphix, also used in Petra for Texas land grid and all culture
• DXF file - Native file format for AutoCad and Kingdom SMT
• Platte River file -Native land grid file format for Petra, also called T/R Digitize file format
• KML file - Native file format for Google Earth
• CSV file - General database and spreadsheet format
• WFS - Web Feature Service - enhanced streaming data directly into your mapping software
• WMS - Web Mapping Service - visualized streaming data - limited metadata associated with the stream
• GeoTiff file - Ratser file typically used for DEMs and imagery
• XYZ file - Elevation file used by Landmark software and other oil and gas applications

What is Metadata and what does ours include?

Listing and descriptions for the invidividual field attributes you find in data.

Data and Projection.

Modification and creation dates.

Datums

We provide our pre-pocessed data in two datums - Lat/Long NAD27 and Lat/Long NAD83. If you need your data in a different datum and/or a specific projection (eg. NAD27/State Plane) please make your request after placing your order by contacting us at support@uslandgrid.com. There is no charge for this service.

Vector Data

In a GIS, geographical features are often expressed as vectors, by considering those features as geometrical shapes. Different geographical features are expressed by different types of geometry:

Points

A simple vector map, using each of the vector elements: points for wells, lines for rivers, and a polygon for the lake.

Zero-dimensional points are used for geographical features that can best be expressed by a single point reference—in other words, by simple location. Examples include wells, peaks, features of interest, and trailheads. Points convey the least amount of information of these file types. Points can also be used to represent areas when displayed at a small scale. For example, cities on a map of the world might be represented by points rather than polygons. No measurements are possible with point features.

Lines or polylines

One-dimensional lines or polylines are used for linear features such as rivers, roads, railroads, trails, and topographic lines. Again, as with point features, linear features displayed at a small scale will be represented as linear features rather than as a polygon. Line features can measure distance.

Polygons

Two-dimensional polygons are used for geographical features that cover a particular area of the earth's surface. Such features may include lakes, park boundaries, buildings, city boundaries, or land uses. Polygons convey the most amount of information of the file types. Polygon features can measure perimeter and area.

Each of these geometries are linked to a row in a database that describes their attributes. For example, a database that describes lakes may contain a lake's depth, water quality, pollution level. This information can be used to make a map to describe a particular attribute of the dataset. For example, lakes could be coloured depending on level of pollution. Different geometries can also be compared. For example, the GIS could be used to identify all wells (point geometry) that are within one kilometre of a lake (polygon geometry) that has a high level of pollution

Vector features can be made to respect spatial integrity through the application of topology rules such as 'polygons must not overlap'. Vector data can also be used to represent continuously varying phenomena. Contour lines and triangulated irregular networks (TIN) are used to represent elevation or other continuously changing values. TINs record values at point locations, which are connected by lines to form an irregular mesh of triangles. The face of the triangles represent the terrain surface.

GIS File Formats

Vector formats

• AutoCAD DXF - contour elevation plots in AutoCAD DXF format (by Autodesk)
• Coverage - Esri's closed, hybrid vector data storage strategy. Legacy ArcGIS Workstation / ArcInfo format with reduced support in ArcGIS Desktop lineup
• Digital Line Graph (DLG) - a USGS format for vector data
• Enterprise Geodatabase - Esri's geodatabase format for use in an RDBMS
• File Geodatabase - Esri's file-based geodatabase format, stored as folders in a file system
• Geography Markup Language (GML) - XML based open standard (by OpenGIS) for GIS data exchange
• GeoJSON - a lightweight format based on JSON, used by many open source GIS packages
• GeoMedia - Intergraph's Microsoft Access based format for spatial vector storage
• ISFC - Intergraph's MicroStation based CAD solution attaching vector elements to a relational Microsoft Access database
• Keyhole Markup Language (KML) - XML based open standard (by OpenGIS) for GIS data exchange
• MapInfo TAB format - MapInfo's vector data format using TAB, DAT, ID and MAP files
• Personal Geodatabase - Esri's closed, integrated vector data storage strategy using Microsoft's Access MDB format
• Shapefile - Esri's open, hybrid vector data format using SHP, SHX and DBF files
• Simple Features - Open Geospatial Consortium specification for vector data
• SOSI_Standard - a spatial data format used for all public exchange of spatial data in Norway
• Spatial Data File - Autodesk's high-performance geodatabase format, native to MapGuide
• TIGER - Topologically Integrated Geographic Encoding and Referencing

Raster formats

• ADRG - National Geospatial-Intelligence Agency (NGA)'s ARC Digitized Raster Graphics
• BIL - Band Interleaved by Line (image format linked with satellite derived imagery)
• CADRG - National Geospatial-Intelligence Agency (NGA)'s Compressed ARC Digitised Raster Graphics (nominal compression of 55:1 over ADRG)
• CIB - National Geospatial-Intelligence Agency (NGA)'s Controlled Image Base (type of Raster Product Format)
• Digital raster graphic (DRG) - digital scan of a paper USGS topographic map
• ECRG - National Geospatial-Intelligence Agency (NGA)'s Enhanced Compressed ARC Raster Graphics (Better resolution than CADRG and no color loss)
• ECW - Enhanced Compressed Wavelet (from ERDAS). A compressed wavelet format, often lossy.
• Esri grid - proprietary binary and metadataless ASCII raster formats used by Esri
• GeoTIFF - TIFF variant enriched with GIS relevant metadata
• IMG - ERDAS IMAGINE image file format
• JPEG2000 - Open-source raster format. A compressed format, allows both lossy and lossless compression.
• MrSID - Multi-Resolution Seamless Image Database (by Lizardtech). A compressed wavelet format, allows both lossy and lossless compression.
• netCDF-CF - netCDF file format with CF medata conventions for earth science data. Binary storage in open format with optional compression. Allows for direct web-access of subsets/aggregations of maps through OPeNDAP protocol.