Analysis of three major file formats of ArcGIS

 

Analysis of three major file formats of ArcGIS

Shape Data The shapefile is ArcView GIS 3. the native data format of X is a simple element class. It uses the shape of point, line, and polygon to store elements, but cannot store topological relationships. It has the advantages of simple and fast display. A shapefile is composed of several files. The spatial information and attribute information are stored separately. Therefore, it is called "file-based ". Each shapefile must consist of at least three objects: *. SHPStores the spatial information of geometric elements, that is, XY coordinates. *. ShxThe index information stored in *. SHP is stored. It records how space data is stored in *. SHP, where the input point of XY coordinates is, and how many XY coordinate equivalence information are there. *. DBFDBASE table for storing attribute information of geographic data These three files are basic files of a shapefile. The shapefile can have other files, but all these files have the same name as the shapefile and are stored in the same path. Other common files: *. PrjIf shapefile defines a coordinate system, its spatial reference information will be stored in the *. prj file. *. SHP. xmlThis is the XML Metadata File generated after metadata browsing for the shapefile. *. SBNAnd*. SbxThese two storage space indexes of shapefile can accelerate the reading of space data. These two files are generated after the data is operated, browsed, or connected. You can also use the arctoolbox> data management tools> indexes> Add spatial index tool to generate them. When you use arccatalog to create, move, delete, or rename a shapefile, or use ArcMap to edit the shapefile, arccatalog automatically maintains data integrity and changes all files synchronously. Therefore, you need to use arccatalog to manage shapefile. Although shapefile cannot store topological relationships, it is not a common graphic file used for display. As geographic data, it has its own topology. For example, for a polygon element class, shapefile sorts all its vertices in clockwise direction, and then edge vectors connected to each other in vertex order, inside the Polygon on the right of the vector, the left side of the vector is the exterior of the polygon. Due to the rapid development of geographic information in the 1990 s and the worldwide promotion of ArcView GIS 3. X software, data in the shapefile format is widely used and has many data sources. Many software products provide interfaces for shapefile conversion (such as Mapinfo and MAPGIS ). ArcGIS supports editing shapefile and converting shapefile to the third-generation data model Geodatabase.

1. SHP stores the spatial information of geometric elements, that is, XY coordinates.
Shx stores the index information stored in. SHP, that is, the storage method of space data in SHP, where the XY coordinate input points are, and how many XY coordinate equivalence information are there.
Dbf dbase table for storing the attribute information of geographic data
Prj stores the file space reference information, such as the coordinate system.
SHP. xml: XML Metadata File generated after metadata browsing
SBN and sbx store spatial indexes on shapefile to accelerate the reading of spatial data.

Coverage data

Coverage is the native data format of ArcInfo Workstation. It is called "folder-based storage" because in Windows Resource Manager, its spatial information and attribute information are stored in two folders respectively. For example, in the E: \ mytest \ example folder on my computer, there are three coverages, as shown in status 1 in Windows Resource Manager, all information is stored in folders. Space information is stored as a binary file in an independent folder. The folder name is the coverage name, and the property information and Topology data are stored as INFO tables. Coverage combines spatial information and attribute information, and stores the topological relationship between elements.

Coverage is a very successful early geographic data model that has been well received by users for more than 20 years. Many of the early data is in the coverage format. ESRI does not disclose the coverage data format, but provides an interchange file (e00) for coverage format conversion, and discloses the data format, this facilitates the conversion between coverage data and data in other formats.

However, to promote its third-generation data model Geodatabase, ESRI has shielded the coverage editing function since ArcGIS 8.3. To use data in the coverage format, you can install ArcInfo Workstation or convert the coverage data to another editable data format.

Coverage is a set that can contain one or more element classes.

 

 

The AAT arc section Attribute Table records the starting and ending point coordinates of the arc section.
The ADF is in coverage format, including lab. ADF, arc. ADF, sec. ADF, pal. ADF, CNT. ADF, tic. ADF, lnk. ADF, BND. the coordinate information is recorded in the ADF. ADF, Pax. the ADF is the index file and Pat. ADF, AAT. the ADF is an attribute file.
The Pat point Attribute Table that records the coordinate information of the lable point.
TIC control point, used to register map points
Aux saves auxiliary information that cannot be saved by the raster file itself, including color map information, histograms or tables, coordinate systems, transformation information, and projection information.
RRD Stores image pyramid information indexes to accelerate display and roaming
Dat Property Information
Nit Attribute Table definition file
Dir Attribute Table Path Management file, used to associate DAT and NIT

Geodatabase data

 

Geodatabase, as the native data format of ArcGIS, reflects the advantages of many third-generation geographic data models. With the development of IT technology, the management mode of common transactional data has already changed from traditional file-based management to the management of relational databases based on industrial standards, the advantages of this database-based management method are self-evident. Can geographic data with spatial information be managed using this very mature database technology? ESRI introduced the Geodatabase data model, which uses the database technology to efficiently and securely manage our geographic data.

Geodatabase can be divided into two types, one is based on Microsoft AccessPersonal GeodatabaseThe other is based on Oracle, SQL Server, Informix, or DB2Enterprise GeodatabaseBecause it requires the middleware ArcSDE to connect, enterprise geodatabase is also called ArcSDE Geodatabase. Due to the limitation of Microsoft Access capacity
The maximum capacity of geodatabase is 2 GB, which obviously cannot meet the storage requirements of enterprise-level massive geographic data. As a result, Geodatabase can be extended to ArcSDE Geodatabase. The underlying database can use a large relational database such as Oracle to store almost "unlimited" massive data (only limited by the hard disk size ). Although the underlying databases are different, Geodatabase provides users with a consistent operating environment.

Geodatabase not only stores simple element classes similar to shapefile, but also supports element sets similar to coverage. It also supports a series of behavior rules to verify its spatial information and attribute information. Tables, associated classes, grids, notes, and dimensions can all be stored as Geodatabase objects. These are the same in perasonal Geodatabase and ArcSDE Geodatabase (the storage of raster is slightly different, but they are the same for users )., Is a personal Geodatabase.

Edit the personal Geodatabase and use the license of ArcView. You can connect directly without additional software. However, personal Geodatabase does not support multi-user editing and can only meet the requirements of small projects.

The ArcSDE Geodatabase connected through ArcSDE requires at least the license of arceditor to edit it. ArcSDE Geodatabase supports multi-user and long transaction editing through a version mechanism.

In arctoolbox> conversion tools> to Geodatabase, multiple conversion tools support conversion from vector data such as coverage, shapefile, and CAD to Geodatabase. You only need to copy and paste the data between personal Geodatabase and ArcSDE Geodatabase without conversion.

 

ADF-ARC/INFO coverage data file
AGF-Atlas GIS Native Binary geodataset File
Ain-attribute index file
AIH-attribute index file
Alg-ER Mapper Algorithm
Apr-ArcView project file (ODB format)
AVL-legend template file (ODB format)
AVP-palette file (ODB format)
Ave-Avenue script
Avx-ArcView extension file (ODB format)
Ai-Adobe illlustrator picture file
Bat-DOS batch file
BIL-image file (band interleaved by line)
Bip-image file (band interleaved by pixel)
Blw-world file for Bil Image
BMP-Windows bitmap image file
BPW-world file for BIP or BMP Images
Bsq-image file (band sequential)
Bqw-world file for bsq Image
C-C programming language source code filename
Cat-Unix hyperhelp supporting file
CGM-Computer Graphics Metafile
CLS-geocoding classification file
CNT-Help File Contents
Dat-generic data file extension dat-Info attribute File
DB-object database file (also ODB)
DBF-DBASE tabular data file
DBF-shapefile Attribute Table File
Dbg-problem debug log file
DCP-default codePage File
DCT-geocoding dictionary file
Dec-Unix hyperhelp supporting file
Def-defaults file (North arrows, layout templates, etc) (ODB format)
Dem-digital elevation model file
Dgn-design drawing file (Intergraph)
Dir-Info Directory Manager File
DLG-Digital Line Graph File
DLL-Windows dynamic link library file
Doc-MS-word, MS-Wordpad document file
DTD-Unix hyperhelp supporting file
DWG-drawing file (AutoCAD)
DXF-Drawing Exchange File
E00-ARC/INFO Export File
ECW-ER Mapper enhanced compressed Wavelet
EPS-encapsulated postscript
ERS-ER Mapper raster File Format
Exe-dos/Windows Executable File
Fbn-spatial index file for read-only Datasets
Fbx-spatial index file for read-only Datasets
FLS-Windows Help supporting file
Ftg-Unix help supporting file
FTS-Unix help supporting file
Gen-ARC/INFO ungenerate format
GFW-world file for GIF Image
GIF-image file (CompuServe)
HDR-header file (for ArcView extensions or TIF images)
HlP-Windows Help File
Htm-WWW file (hypertext markup, 3-character DOS version)
HTML-WWW file (hypertext markup language, Unix Version)
Ico-icon file
Idx-geocoding index for read-only Datasets
IMG-ERDAS Imagine Image File
Ini-Initialization File
Ixc-geocoding index for read-write coverages
Ixs-geocoding index for read-write shapefiles
Jpg-image file (joint photographic Experts Group)
Key-geocoding matching keys (ODB format)
Lin-ARC/INFO lineset symbol file
Lnk-windows shortcut cut icon link file
Mat-geocoding matching parameters file
MCP-image file (macpaint)
Mid-MapInfo interchange format (always used red with "MIF ")
Mif-MapInfo interchange format (always used red with "mid ")
MRK-ARC/INFO markerset symbol file (not compatible w/ArcView)
Mxc-geocoding index for read-write coverages (ODB format)
MXs-geocoding index for read-write shapefiles (ODB format)
Nit-Info table definitions File
Ndx-fonts index file (unix only)
NLS-codePage language files
ODB-object database ASCII file (ODB format)
Pat-geocoding Pattern Recognition File
PDF-preferences definition file
PIF-Windows program information file (for DOS Programs)
PPS-processing set Codes
Prj-projections definition file
PS-postscript. File
RLC-image file (run-length coding)
RS-image file (raster snapshot | sun rasterfile)
SBN-spatial index for read-write shapefiles
Sbx-spatial index for read-write shapefiles
SHD-ARC/INFO shadeset symbol File
SHP-shapefile (stores Feature Geometry)
Shx-shapefile (stores file lookup index)
STN-geocoding standardization File
Tab-lookup File
TBL-geocoding support table
TIF-image file (TAG Image Format File)
Tfw-world file for TIF Image
TMP-temporary file
TTF-TrueType font file
TXT-text file (usually ASCII)
Xbm-image file (x Bitmap)
WMF-image file (Windows Metafile)
Wld-world file for CAD Datasets
WRI-Windows write.exe File