1. Working with spatial data
Introduction to GIS
Working with spatial data
CGIS-NURIntroduction to ArcGIS I

2. Lesson 5 overview Geographic data review
Introduction to GIS
Lesson 5 overview
Geographic data review
Linking features and attributes
Data formats
Working with ArcCatalog
Where you find support
CGIS-NURIntroduction to ArcGIS I

3. Representing geographic features
Introduction to GIS
Representing geographic features
Vector
Raster
Data has
X,Y
Column
Row
Behavior rules
Geometry
Attributes
Representing geographic features
The two basic models for digitally storing geographic data are vector and raster. The vector model uses discrete coordinates (commonly known as x,y coordinate pairs) to represent geographic features as points, lines, or polygons. The raster model uses equally sized square cells to represent features; the level of detail depends on the size of the cells. Each data model has pros and cons: vector data is cheap to store but expensive to process; raster data is cheap to process but expensive to store. Also, different physical phenomena may be more suited to one data type versus the other (e.g., rainfall is more suited to a raster data model, surveyed lines are more suited to the vector data model).
GIS data is made up of three basic components: geography (the spatial representation of the features), attributes (the descriptive characteristics of the features), and behavior rules (instructions that govern what the features can and cannot do).
CGIS-NURIntroduction to ArcGIS I

4. Introducing feature classes
Introduction to GIS
Introducing feature classes
Collections of features with the same type of geometry
Can create point, line, or area feature classes
Many different line objects
primary roads
Single linear feature class “Roads”
highways
Introducing feature classes
You know about point, line, and area abstraction. Given these choices, it would be impractical to store every line in its own dataset. Feature classes allow you to aggregate homogeneous features into a single collection. For example, highways, primary roads, and secondary roads can be grouped into a line feature class named “Roads”. All customers for each business franchise can be grouped into a point feature class named ‘customers’. Territories for homogeneous wildlife species can be grouped into a polygon feature class named ‘habitat’.
The term ‘feature class’ is used to refer to any grouping of points, lines, or polygons, regardless of the data storage format.
What’s a Layer?
The word ‘layer’ can be used generically to describe any individual (usually) horizontal stratum used to organize different logical groupings of spatial data. In ArcGIS, the word ‘layer’ is used to describe a specific object or file used to symbolize a feature class. Refer to Lesson 3 to review.
secondary roads
CGIS-NURIntroduction to ArcGIS I

5. Linking features and attributes
Introduction to GIS
Linking features and attributes
Feature classes are tables that store spatial data
Each feature has a record in the table
Unique identifier links feature and attributes
FID = 18699
Linking features and attributes
For geographic objects stored in a feature class, each individual feature is assigned a unique numerical identifier and is characterized by a unique location in space and corresponding record in an attribute table. While the exact name of the numerical identifier may differ by the data format, it is important to understand this one-to-one relationship between feature, identifier, and attribute record.
Feature Identifier
CGIS-NURIntroduction to ArcGIS I

6. Introduction to GIS
Spatial data formats
ArcGIS can work with spatial data in multiple formats
Coverage
Geodatabase
Shapefile
Internet Map Service
CAD
Raster
Tables
Spatial data formats
Currently, there is not a standard format for GIS data. Various GIS software manufacturers and other organizations, such as government agencies, have continually searched for more efficient and versatile digital formats to store geographic information. ArcGIS has the advantage of seamlessly supporting all of the ESRI formats: shapefiles, coverages, GRIDs, the geodatabase, and data served over the Internet by ArcIMS. ArcGIS also supports the three most common CAD file formats (DXF, DWG, and DGN), as well as a variety of common image formats. Having the ability to work with so many different formats without needing to convert them is a tremendous advantage.
More information describing all of the data types supported by ArcGIS can be found in the ArcGIS Desktop Help files by entering the keywords ‘data types’ under the Index tab.
ArcGIS
CGIS-NURIntroduction to ArcGIS I

7. Demonstration
Spatial data in ArcCatalog

8. Geodatabase data format
Introduction to GIS
Geodatabase data format
Stores spatial features and their attributes in the same RDBMS
Feature datasets model spatial relationships
Stand-alone feature classes
RDBMS table
Coffee point
feature class
Data format: Geodatabase
In contrast to coverages and shapefiles, which store feature coordinate and attribute information in separate files, the geodatabase stores both types of information in one database. This centralization of storage offers many advantages. Each geodatabase feature class stores a single feature type (point, line or polygon), but you can easily group them into a collection called a feature dataset as long as they have the same spatial reference.
The term geodatabase is used to refer to a storage format. ArcGIS supports five physical implementations of the geodatabase: A file geodatabase, an Access based personal geodatabase, as well as a personal, a workgroup and an enterprise geodatabase.
File and Access geodatabases are designed for smaller-scale projects with single user editing. File geodatabases are a collection of geographic datasets of various types held in a common file system folder, while Access geodatabases are stored as a Microsoft Access database. You do not need to purchase any additional software to access and manage these geodatabases.
The personal, workgroup and enterprise geodatabases are designed for larger enterprise GIS applications, with multi user editing. They require ArcSDE as additional software and a relational database management system (RDBMS). Personal and workgroup geodatabases use SQL Server Express as their RDBMS, while Enterprise geodatabases can be stored in any of the supported RDBMS formats (Oracle, Microsoft SQL Server, IBM DB2, IBM Informix). Regardless of the physical implementation, you can perform the same display, query, and analysis operations on all types of geodatabases. Note that there are some differences in functionality due to physical storage issues.
The geodatabase is a native data format for all ArcGIS applications. The ArcView license level allows you to create, edit, and delete file- or personal geodatabase features and use ArcSDE geodatabase features for various processes, such as queries, joins, and relates. The ArcEditor and ArcInfo levels of ArcGIS allow you to create, edit, and delete ArcSDE, file- or personal geodatabase feature classes.
Shape field accesses separate coordinate table
CGIS-NURIntroduction to ArcGIS I

9. Advantages of the geodatabase
Introduction to GIS
Advantages of the geodatabase
A relational database management system (RDBMS) for spatial and attribute data
Multiuser editing
Manage raster and
vector data
Single storage
location
Geodatabase
Custom features
Spatial and Attribute
validation
Relationships
Advantages of the geodatabase
The geodatabase provides:
Centralized spatial and attribute storage
Easy to use standard behavior rules
Multiple customization options
Multiuser editing (workgroup and enterprise geodatabases only)
The geodatabase supports a variety of modeling, management, and analysis functions. One of its key benefits is that its implementation of tables, feature classes, feature datasets, and rules allows you to model reality more closely than was possible with other data models.
The geodatabase data model can minimize the differences between logical and physical models of reality by incorporating more intuitive data objects. For example, a coverage or shapefile provides a mechanism to store a generic point feature that may require ARC Macro Language (AML) or Avenue programs to maintain its attribute validation rules and other behavior. The geodatabase lets you store an electrical transformer feature instead of just a generic point feature and then apply subtypes, attribute domains, and relationship rules and/or topological rules.
Because your datasets are smarter, it is easier to create and maintain your data. The ability to model simple and complex relationships through the graphical user interface (GUI) means that no external programming is needed for most customization. An added bonus for workgroup and enterprise geodatabases is the ability to support multiuser editing through versioned geodatabases.
Scalable storage
solutions
CGIS-NURIntroduction to ArcGIS I

10. Geodatabase validation
Introduction to GIS
Geodatabase validation
Automate spatial feature and attribute behavior
Speeds up data entry
Enforces quality control
Attribute validation
Relationship classes
Domains
Subtypes
Spatial validation
Geometric network
Topology
Validation means that geographic features can be made to allow certain types of editing, display, or analysis behavior, depending on circumstances that the user defines. Feature behavior is most easily implemented in the geodatabase. In the geodatabase, you can set two types of validations: spatial and attribute.
Spatial validation
Spatial validation can be used in two ways: topology or geometric networks. Both of these spatial validation types require a feature dataset, where dedicated feature classes participate in either the topology rules or the geometric network rules. A single feature class cannot participate in both. Both of these spatial validations are available in ArcEditor and ArcInfo.
Attribute validation
Attribute validation are of three types: subtypes, domains, and relationship classes. These types of validations are necessarily used with tabular data. Both of these validations are required for maintaining data integrity and efficiency during management, display, and editing operations on the geodatabase. ArcView and above can create and edit domains; subtypes can be created with ArcView, ArcEditor and ArcInfo.
More information regarding any of these topics can be found in a variety of sources:
ArcGIS Desktop Help
Online at
Instructor-led courses (e.g., Introduction to ArcGIS II, Building Geodatabases I and II)
Virtual Campus courses (e.g., Basics of the Geodatabase Data Model; Creating, Editing, and Managing Geodatabases for ArcGIS 8.3)
CGIS-NURIntroduction to ArcGIS I

11. ESRI shapefile data format
Introduction to GIS
ESRI shapefile data format
Shapefile
Single feature class
Attributes stored in dBASE table
Made up of separate files
Can create and edit with ArcGIS or ArcView 3.x
Use only ArcCatalog to manage shapefiles
Data format: Shapefile
Shapefiles can only contain one feature class. Therefore, a donut shop point feature class (representing the building’s point location) must be stored in a different shapefile as a donut shop polygon feature class (representing the building’s footprint).
Regardless of feature type, a shapefile’s default attribute table is stored in dBASE format and is named shapefile.dbf (e.g., donut.dbf). You can access this table in ArcGIS applications or dBASE. Additionally, shapefiles are the native format for ArcView 3.x, so you can view, display, and edit both the spatial and attribute data in ArcView 3.x.
Shapefiles are a vector file structure for storing the location and attribute information of points, lines, or areas. Each shapefile consists of at least three files: <name>.shp, <name>.shx, and <name>.dbf (e.g., donut.shp, donut.shx, and donut.dbf). However, there may be other files associated with the shapefile, which you might not recognize and therefore miss if you tried to copy or move the shapefile using your computer operating system. This is why you should only use ArcCatalog to copy, move, or rename shapefiles.
CGIS-NURIntroduction to ArcGIS I

12. Managing raster data Rows and columns of equal-sized cells
Introduction to GIS
Managing raster data
Rows and columns of equal-sized cells
Each cell stores a value
Detail depends on cell size
GRID (the ESRI native raster format)
Images (TIFF, BMP, SID, JPEG, ERDAS)
Data format: Images and Grids
Raster data files use rows and columns of equally spaced cells to model reality. There is a trade-off between file size and how closely you want to model reality. If you assume a given spatial extent, a small cell size (e.g., 6-inch pixel) captures more detail, but the raster file size is larger than a large raster cell size (e.g., 50-meter pixel), which captures less detail. It is not uncommon for a single high-resolution (i.e., small cell) image to be many gigabytes in size.
Raster collection mechanisms
A raster data source can be composed of a single layer or a collection of multiple layers, which appear to act as one (composite). ArcGIS supports many raster image formats, and these may be monochrome (black and white) or multispectral (many bands, or layers, representing many colors).
ArcCatalog allows you to manage individual raster data sources in two ways: a Raster Dataset represents a single source of raster information; a Raster Catalog represents a number of individual raster data sources, which are displayed and managed as one.
ArcGIS also uses an ESRI raster format called GRID. GRIDs may use a collection mechanism called a grid stack, which is used for certain types of analysis. There are several different types of GRIDs, so you should read the online documentation for more information about their formats and capabilities.
Raster management in ArcGIS
If you only want to manage the storage or display of rasters in ArcGIS, you can use ArcCatalog. However, if you need to use ArcGIS to create, edit, manipulate, or analyze raster datasets, you will need the Spatial Analyst extension.
CGIS-NURIntroduction to ArcGIS I

13. Using ArcCatalog Provides a uniform view of all your data
Introduction to GIS
Using ArcCatalog
Provides a uniform view of all your data
Define or modify table and feature class definitions
Manage data: Copy, Rename, Delete
Additional data management tools with the ArcToolbox window
Using ArcCatalog
ArcCatalog is the application where you create and manage connections to all the data you need to use. When you create a connection, you access the data to which it is linked, whether it is located on a local disk or a database on the network. Together, your connections create a ‘catalog’ of geographic data sources.
Within ArcCatalog, you can move, copy, rename, and delete geographic data. You can create, manage, and edit associated metadata, and you can perform some modifications to the data, such as adding fields to tables, defining subtypes, creating domains, and building table relationships.
By adding the ArcToolbox window, you can also access all of the data management tools contained within the various toolboxes.
CGIS-NURIntroduction to ArcGIS I

14. ArcCatalog - Three ways to view data
Introduction to GIS
ArcCatalog - Three ways to view data
Contents
Preview
Metadata
Three ways to view data
In ArcCatalog, you can browse your data holdings three ways using three tabs:
Contents tab
The Contents tab shows what a selected item (e.g., folder, geodatabase, or feature dataset) in the catalog tree contains. There are four ways to view the contents of the item: as large icons, in list form, showing details (like data type), and in thumbnail view.
Preview tab
The Preview tab previews the selected item’s geographic or tabular data. Geography view is the default preview mode. For items containing both geographic data and tabular attributes, you can toggle between the two preview types using the drop-down list at the bottom left corner of the Preview view.
The available previews are not limited to Geography and Table. Developers can create their own custom previews and add them to the list. For example, an AML view might let you preview the contents of an AML file that has been added to the database.
Metadata tab
The Metadata tab shows a selected item’s metadata. By default, when you first try to view an item’s metadata, ArcCatalog automatically generates it if it does not already exist. Upon creation, ArcCatalog adds several of the data source’s properties to the metadata. The next time you view or edit the metadata, ArcCatalog will automatically update these properties with the current information.
CGIS-NURIntroduction to ArcGIS I

15. The Contents tab Large icons List Details Thumbnails Data Layers Maps
Introduction to GIS
The Contents tab
Large icons
List
Details
Thumbnails
Data
Layers
Maps
The Contents tab
The Contents tab lists the items contained in any item you select in the catalog tree, such as folders, geodatabases, or feature datasets. In the Contents tab, you can look at the data listed in four different ways:
Large icons: All items are represented by a large icon graphic in the main display window.
List: The items are shown in a simple list with small icons to the left of the file names.
Details: The items are shown in a simple list with small icons to the left of the file names (similar to the list view option), but additional information is also given, such as each file’s data type.
Thumbnails: All items are represented by thumbnail images in the main display window. The thumbnails are snapshots of the data at the time the thumbnail was created. Therefore, the thumbnail images can quickly become outdated and should be updated frequently.
By default, thumbnails are automatically generated for map documents. For other items, a thumbnail must be created manually. If a thumbnail has not been created for an item, an icon describing the data type and name of the item appears in place of the thumbnail.
CGIS-NURIntroduction to ArcGIS I

16. The Preview tab Geography or Table view Choose from drop-down list
Introduction to GIS
The Preview tab
Geography or Table view
Choose from drop-down list
Build custom views
The Preview tab
When an item is selected in the Catalog tree, the Preview tab previews the selected item’s geographic or tabular data. At the bottom of the tab, there is a drop-down list that allows users to select which view they would like to see (either geography or table). Geography is the default view, where the data is displayed with a random color and/or symbol set. The table view option displays the attribute data associated with the selected feature class in tabular form.
A third preview option, 3D view, is also possible if the 3D Analyst Extension has been added. You can build your own custom views if these three options do not meet the needs of your organization. A
CGIS-NURIntroduction to ArcGIS I

17. Introducing metadata Descriptive information about data source
Introduction to GIS
Introducing metadata
Descriptive information about data source
Metadata tab
Description
Spatial
Attributes
Metadata toolbar
Create and edit content
Convert between different file formats
Introducing metadata
Often the definition given for metadata is ‘data about data’. While this definition is not incorrect, it is not very informative. More precisely, metadata supports descriptive information about data. Text written on the back of a photograph telling you the photograph’s date and subject and nutrition labels on food containers are common examples of everyday metadata. For spatial data, metadata includes descriptive information such as date, creator, geographic extent, coordinate system, and attribute domains. Metadata gives your data credibility, and in many situations, your data may be impossible to interpret or use without it.
The Metadata tab in ArcCatalog displays the metadata for a selected dataset. If metadata does not exist for the selected dataset, ArcCatalog creates as much metadata as it can from the existing information. For the FGDC ESRI stylesheet, the Metadata tab is divided into three categories, each with an active tab:
Description—contains the basic narrative information about the dataset, including source, organization, date, uses, and restrictions.
Spatial—contains the coordinate information and geographic extent of the dataset.
Attributes—includes fields, attribute domains, and related tabular information.
You can create, edit, import, and export the metadata for any given dataset. Because metadata information is stored in XML format, you can use it with other software that can read XML documents.
CGIS-NURIntroduction to ArcGIS I

18. The Metadata tab Create and display metadata in a variety of ways
Introduction to GIS
The Metadata tab
Create and display metadata in a variety of ways
FGDC Classic
FGDC_ESRI
XML
ISO
Viewing metadata
You can view metadata in ArcCatalog by selecting an item in the catalog tree and then clicking the Metadata tab in the display area. There are a number of stylesheets available in ArcCatalog to view metadata. Stylesheets format data from a database and present the results as a report. Metadata is stored as an Extensible Markup Language (XML) file, and the stylesheets define how XML data is presented. Stylesheets are written using Extended Stylesheet Language (XSL). The stylesheets in ArcCatalog represent common standards for metadata. However, you can create your own customized stylesheet for displaying metadata in ArcCatalog using XSL.
The Federal Geographic Data Committee (FGDC) is an organization established by the United States Federal Office of Management and Budget responsible for the coordination of development, use, sharing, and dissemination of surveying, mapping, and related spatial data. It is composed of representatives from several federal agencies and GIS vendors. The FGDC defines spatial metadata standards in its Content Standards for Spatial Metadata, and it coordinates the development of the National Spatial Data Infrastructure (NSDI).
The International Organization for Standardization (ISO) is another common standard for collecting metadata on spatial data.
CGIS-NURIntroduction to ArcGIS I

19. Connecting to folders Connect to any folder in your network
Introduction to GIS
Connecting to folders
Connect to any folder in your network
Connect through Network Neighborhood to store a Uniform Naming Convention (UNC) path
Example \\servername\foldername\filename.ext
Use UNC in layer files or map documents
Disconnect from folders
Connecting to folders
Unlike Windows Explorer, ArcCatalog does not list all files stored on disk; so when you look in a folder, it might appear to be empty. By default, ArcCatalog only lists geographic data files. By default, ArcCatalog can access several types of geographic data (e.g., shapefiles, coverages). To enable ArcCatalog to access a new type of data, both spatial and nonspatial types, you need to specify the data type in the File Types list in the Options dialog box.
When you first start ArcCatalog, it contains folder connections that let you access your local computer’s hard disks along with other folders called ‘top level’ directories (e.g., Coordinate Systems, Address Locators). You can add additional folder connections that access specific folders or directories on a local disk, shared folders on the network, or the contents of a floppy or CD-ROM drive when needed. You can also connect through Network Neighborhood to store a Uniform Naming Convention (UNC) path. You can use UNC for layer files or map documents to reference a layer’s source data. Lastly, you can remove folder connections and hide other folders that you do not need.
CGIS-NURIntroduction to ArcGIS I

20. Where you find support Desktop Help ESRI Knowledge Base
How to use the software
Programs > GIS > ArcGIS > ArcGIS Desktop > ArcGIS Desktop Help
Online or on your computer:
ESRI Knowledge Base
How to solve technical problems