Loading Layers from Feature Files
You can load layers from the following feature file types:
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Feature File |
Description |
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Esri Shapefile |
A shapefile is a simple, non-topological file format used for storing the geographic location and attribute information of geographic features. This file format, developed by the Environmental Systems Research Institute (ESRI), was designed for the Esri GIS and mapping system and consists of the following files: § .shp: The main file that stores records of shapes, geometry and vertices. § .dbf: The dBASE file type that stores attributes data for each geographic object (points, lines and polygons). § .shx: The index file that stores the offset of the related .shp file. § .qix: A spatial index file created by TerraExplorer Pro when adding a shapefile as a streaming layer for the first time. |
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Excel File |
A spreadsheet file that contains data for analysis and manipulation using tables and formulas. Note: Both *.xls and *.xlsx files are supported. TerraExplorer can read geographic location elements (points) from an Excel file, which is made possible by the user identifying the geographic fields. Excel Files Basic Rules: § Each sheet in the file represents a single geographic layer. § Each row in a sheet represents a single geographic location. § Each row in the file should contain, at least: an X and Y coordinate (column). Coordinate columns should be in a Number Data Type and Double Field Size. Note: Opening *.xlsx files on computers running a 64-bit version of Windows requires either Office 32-bit or ACE 32. |
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Text File |
A Text file is a free format file describing geographic locations of elements (points). Text files can be generated manually using a common text editor or loaded from other data forms (e.g., exported files from Microsoft Excel or from a Rational database). Note: Both *.txt and *.csv files are supported.
Text Files Basic Rules: § Each line in the file represents a single geographic location. § Each line in the file contains, at least, an X and Y coordinate, and content data. § Every line must have the same number of columns. Corresponding columns must have the same data types (although optional parameters are allowed). § Optional parameters may be represented by empty spaces when using a TAB, comma or semi-colon as separators. For example, if the column format is "X, Y, H, P" where only "X" and "Y" are mandatory parameters, "X, Y" is sufficient to set the X and Y values only, but “X, Y, P” is required to set the P value. § When using SPACE as a separator, the number of spaces in between columns is irrelevant. Therefore, empty parameters are not allowed in this type of file. § It is mandatory that the chosen separator from the Select Text File dialog is exactly the same as the separator used in the file. For custom separators, it is required that the characters used are not in conflict with the data. For example, if the data contains a URL in the form “http://<URL>,” using a colon as a custom separator, TerraExplorer distinguishes “http” as one column, and “//<URL>” as another. |
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Esri File Geodatabase (*.gdb) |
A File Geodatabase stores as a folder of files that hold geographic data, attribute data, index files, lock files, and a signature file as well as other files. Each feature class or table in the geodatabase is stored in two or more files. |
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MapInfo file (Tab, Mif, Mid)
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A MapInfo file is a two-dimensional format that stores both feature geometry and attribute information. This file format was developed and regulated by MapInfo. There are two types of MapInfo files: § TAB - MapInfo native format § MIF/MID The TAB format consists of the following files: § .tab: The ASCII file which is the link between all other files and holds information about the type of data file. § .dat: Stores the attribute data. § .id: Stores information linking graphic data to the database information. This file contains an index to the MAP file for each feature. § .map: Stores the graphic and geographic information needed to display a map. § .ind: Optional index files for tabular data. Which are present if any fields are indexed. These files must be kept together in the same directory. The MIF/MID format consists of the following files: § .mif: Stores the geometric data. § .mid: Stores the attribute data. These files must be kept together in the same directory. |
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Microstation DGN
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Microstation DGN files can contain points, lines, areas, text, and other object types. Features all have the following generic attributes: § Type - The integer type code as listed below in supported elements. § Level - The DGN level number (0-63). § GraphicGroup - The graphic group number. § ColorIndex - The color index from the dgn palette. § Weight - The drawing weight (thickness) for the element. § Style - The style value for the element. Note: TerraExplorer supports v7 or lower of the DGN format. |
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A Data Interchange File or *.dxf is an ASCII file format used to exchange vector-based graphics files. This format was developed, and is maintained, by Autodesk for the AutoCAD system. It is one of the most widely supported vector formats in PC-based CAD products. A DXF file is composed of graphic entities such as 2D primitives, 3D primitives and blocks (which are groups of entities). Feature layers based on DXF files are read-only. Layers can contain more than one type of geometry. TerraExplorer Pro supports the following graphical objects and features in DXF files: § Point: An entity with single X, Y, Z coordinates. It can be represented by the “Points Layer Parameters” as listed later in this document. § Arc: Any smooth curve joining two points. § Circle: A set of points equidistant from a given point. § Line: A single line segment. § Polyline: A connected sequence of line segments created as a single object. § 3D Solid: A solid object with free-form surface support. § 3D Face: 3D triangular or quadrilateral plane section. § Text: A single line of alphanumeric characters. § Attrib: An object containing text that links to a block. § Layers: Any drawing entity can be assigned to any layer of the drawing, allowing separation of portions of the drawing. |
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SQLite (*.sqlite, *.db) |
Spatial enabled SQLite databases stored in SQLite 3.x database files. Note: Although non-spatial tables are also supported, they are not recommended for optimal performance. |
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GDAL Virtual Datasource (VRT) |
A VRT file is an XML file that transforms features read from other GDAL feature sources based on criteria specified in the file. The XML control file is essentially a metadata XML file describing various properties of the actual raster/vector file, like pixel dimensions, geolocation, etc. It is primarily used to derive spatial layers from flat tables with spatial information in attribute columns. It can also be used to associate coordinate system information with a data source, merge layers from different data sources into a single data source, or even just to provide an anchor file for access to non-file oriented data sources. See http://www.gdal.org/drv_vrt.html for more information. |
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GeoPackage |
An Open Geospatial Consortium (OGC) standard that at its core, is simply an SQLite database schema. It provides the performance of a spatial database along with the convenience of a file-based data set. |
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Geospatial PDF |
A set of geospatial extensions to the Portable Document Format (PDF) that relate a region in the document page to a region in physical space. |
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S-57 |
Vector interchange format used for maritime charts. Base files normally have the extension .000 while the update files have extensions like .001, .002 etc. The S-57 reader will normally read and apply all updates files to the in memory version of the base file on the fly. The feature data provided to the application therefore includes all the updates. |
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GeoJson |
GeoJSON is a format for encoding a variety of geographic data structures. GeoJSON is an open standard format designed for representing simple geographical features, along with their non-spatial attributes, based on JavaScript Object Notation. The features include points, line strings, polygons, and multi-part collections of these types. |
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Autodesk DWG File |
The native file format for Autodesk’s AutoCAD® software. It is automatically converted to DXF before it is loaded into the project. |
To load a feature file:
1. On the Home tab, in the Add group, click Feature Layer. The Browse for Feature Layer dialog is displayed.
2. Browse to the required file and click Open. The Select Layer dialog opens with the selected layer(s) listed in the Select a Layer section. See “Select Layer Dialog” in this chapter for information.
Note: For text files and Excel spreadsheets, select a layer and click Next. Then select the layer’s Coordinate Fields in the Select Fields dialog and click Next. See “Select Fields Dialog” in this chapter for information.
3. Click Import to directly load with default settings or click Next to set the layer’s general settings.
4. Set the layer’s General Settings and click Next. See “Selecting General Layer Settings” in this chapter for more information. The Layer Settings dialog is displayed.
5. Select the attribute fields to load, set layer and layer object parameters, and apply different properties such as line color or cylinder height, based on the attribute field values of the objects. See “Loading Layer Attribute Fields”, and “About Basing Native Feature Layer Properties on Layer Attribute Fields” in this chapter for information.