Introduction to GIS: ArcCatalog
This tutorial will enable you to identify different forms of GIS data, preview the geographic extent of the data, examine the attribute table associated with a particular dataset, and view the metadata, or information about the GIS data.
Through the activities, you will become familiar with ArcGIS software and to some of the basic concepts of GIS. ArcGIS is a software suite that is composed of three applications: ArcCatalog, for data management; ArcMap, for visualizing and analyzing data; and ArcToolbox, for advanced geoprocessing and data conversion.
ArcCatalog
1. Previewing Data
ArcCatalog is an application for organizing and managing the various datasets and documents used in a GIS. It provides an integrated and unified view of all the data files, databases, and GIS documents available to ArcGIS users. In this application you will find the necessary tools which allow you to:
Browse and find geographic information
Store, view, import, and manage metadata
Define, export, and import data models and datasets
Search for and discover GIS data on local networks and the Web
Start ArcCatalog by double clicking on your ArcCatalog desktop icon or by clicking on Start -> All Programs -> ArcGIS -> ArcCatalog 10.5.
The ArcCatalog window has a catalog display for looking at data, a catalog tree for browsing folders and data, and several toolbars (fig. 1). You will use all three to explore data in our project folder.
The first step in ArcCatalog is to establish connections to the folders and datasets you will be working on. Hit the Connect to Folder button
In the Connect to Folder window that opens see the figure below, navigate to the location of the tutorial data.
Find the new connection listed in the catalog tree.
Select your connection and view the files in the display under the Contents tab. You should see files similar to those listed in the figure above.
There are two main toolbars that you will utilize frequently in ArcCatalog: the Standard and the Geography toolbars. The Standard toolbar provides tools for connecting to data (you used Connect to Folder from this toolbar), for changing the display of data, and for opening other GIS applications. The Geography toolbar provides tools for zooming in and out, for panning, and for returning to full extent view of the data.
Change your view of the data in your project folder by toggling through the display options in the Standard toolbar. These display options are available only when you are viewing multiple data files under the Contents tab. Your four options include the default list of small icons, large icons, a detail view showing file type, and a thumbnail view. Choose the view you prefer to work with.
When trying to find GIS data, it is much more efficient to work on the Catalog Tree side (left side) than on the contents side. Anysymbol on the Catalog Tree next to a folder means that there are data or folders inside that folder. When you click on that
sign, you expand its contents. Click on the on the sign next to Training_PSA_March_2017 (indicates it is a folder), then expand Data ( indicates it is a Geodatabase). Select Dorchester_Parcels in the catalog tree ( represents a polygon Feature Class). Under the contents tab you will see a thumbnail of this file.
Now move to the Preview tab. Here you see that Dorchester_Parcels is a file storing information about the parcel data for the Dorchester county in South Carolina. The display under the Preview tab is where you can preview any geographic data you obtain.
Use the Zoom In tool to view the map in greater detail. You use this tool by drawing a rectangular box around the area that you want to zoom to. Try using the Zoom Out tool to change your view. Instead of clicking, get used to drag windows with these tools. You will end up saving a lot of time.
Use the Pan tool to pan around the map.
2. Attribute Data: Linking features to Information
As discussed above, there's often more to a geographic feature than its location and shape—there is also all of the information associated with that feature, known as attribute data. For a road, this might include its name, speed limit, and whether it is one-way or two-way. For a city, this might include its population, demographic characteristics, and average monthly temperatures.
Select the Dorchester_Parcels feature class in the Preview tab. Make sure to view the whole extent of this layer (hint: use the Full Extent button)
Find the drop down menu at the bottom of the Catalog display. Select Table from this menu.
Now the display changes to show the attribute table associated with the Dorchester_Parcels feature class. As you can see, there are several fields in this attribute table. Each field contains different types of information, see the figure below.
Take a look at the OBJECTID field. This field is automatically generated by ArcGIS when a new feature class is created. Each item in this feature class– in this case, each parcel – is assigned a unique identifier.
3. Metadata
The word ‘metadata’ is broadly defined as data about data. One can also think of it as a historical record of the dataset itself. A metadata record for a GIS dataset can be very detailed, but it typically includes information about
why the dataset was created or collected (its purpose)
what geographic area the dataset covers (its geographic extent)
who created/collected the dataset and when
what processes were performed on the dataset
Metadata is a critical component of sharing data—people searching for a dataset first view its metadata in order to determine whether it is appropriate for the project. If a dataset lacks metadata, it may be used inappropriately—and any analysis or resulting measurements based on the data may be inaccurate. It is very important to know the projection and/or coordinate system of your data, which can be found in the metadata.
1. Let’s go to the Waterbody dataset in the Data to investigate its metadata. Select the Description tab with the feature class selected in the catalog tree.
