ArcGIS is the market leader in geographic information systems for schools. Built to visualize, explore and analyze most forms of geographic data and remote sensed imagery, it is possible to combine point, line, polygon, and image data in ArcGIS. During the online course we will provide the data sets we want you to use to familiarize yourself with the interface. This spring and summer you will go through lessons with a large selection of comprehensive data that can be used in projects. ArcGIS can save and open projects, so work can be shared between users, or between school and home. ArcGIS classifies and symbolizes shapefiles, displays image data, works on data in several projections, and use data distributed over the Internet from several types of services such as ArcGIS online or any web based map service. It is also possible to use ArcGIS with data that is downloaded from a GPS unit to create custom layers of information that then can be related to scientific and other types of data. GIS Data is often freely available over the Internet from cities, counties and federal organizations such as the National Park Service (NPS) and the United States Geologic Survey (USGS) and many of the remote sensing sites we have already learned about.
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The ArcGIS Toolbar
The ArcMap toolbar contains a variety of tools for analyzing and manipulating geographic data. You will learn about the tools as you use them.
With the initial ArcMap startup, you will see a toolbar "floating" to the right.
That toolbar can be moved and "docked" anywhere on the ArcMap interface. To move the toolbar, click and hold on the dark blue title bar at the top of the floating toolbar and drag it to the left or top of your screen.
Unzip the file. A folder called invasive_speciesAM will be created.
Move the entire Invasive_SpeciesAM folder to inside the WEEK5 folder of EYESINTHESKY2.
The navigation path should be: C:/EYESINTHESKY2/WEEK5/Invasive_SpeciesAM
Launch ArcMap by double-clicking its icon on your desktop or by clicking its icon in the Windows Launch Bar.
Choose File > Open, navigate to C:/EYESINTHESKY2/WEEK5 and select the file inv_spc.mxd. Then click Open.
When the project opens, a world map is displayed. Countries are shown in grey and lines of latitude and longitude are drawn at 30 degree intervals.
The map is centered on South America after one click with the Zoom In tool.
Click once on the Zoom to Full Extent tool to take the map all the way back out to a full view.
NOTE: This is a nice trick if you get lost and just want to start over again.
Map zoomed in all the way. Notice the 1:0.01 scale in the numbers circled in the scale box at the top.
As you zoom closer and closer on image (raster) data, you eventually see "pixels," however, vector based data can be zoomed in infinitely without seeing pixels.
The reference numbers in the scale box at the top of the map are the scale of the map represented as a ratio or a fraction. They refer to the level of magnification. At the maximum zoom you see 1: .01 a ratio. In other words, 1 inch on the map would be equal to one hundredth of an inch in reality. As you zoom back out, watch the numbers in the ratio change. When you zoom back to full extent, the scale reads 1:191,512,364. So this means that 1 inch on the map represents 191,512,364 inches, or approximately 3,000 miles.
Use the Zoom Out tool to zoom out several clicks. How far can you zoom out?
When you are done exploring zooming, click the Zoom to the Full Extent tool.
Click your left mouse button and while holding it down, drag out a rectangle across Africa with the Zoom In tool. Notice how this allows for more precise zooming.
Click and drag a box around Africa.
After zooming, the map shows Africa in the center.
Click the Zoom to the Full Extent tool to return to the full map view.
Likewise, you can also use the Zoom Out tool to drag out a box. It is possible to keep zooming out until all you see is just a tiny speck or your map even disappears. Sometimes this might happen unexpectedly, especially if you click and drag out a tiny box with the Zoom Out tool. Try this. Then, experiment zooming in and out so you get a feel for how this works.
Click the Zoom to the Full Extent tool to return to the full map view.
Two other buttons help you navigate on screen. They are the Previous Extent and Next Extent buttons. Try zooming in and then experimenting with these buttons. The Previous Extent button lets you go back to a previous zoom level. Both of these buttons give you unlimited zooms back and forth between levels.
Zoom in around the Azores straight west of Spain and the Mediterranean.
Return to previous
And back again.
When you are zoomed in, you can use the Pan tool to adjust your view. Click and hold the Pan tool and drag your mouse to center your map on another place.
When you are done exploring zooming, click the Zoom to the Full Extent tool.
Move the cursor across the map to discover changes in X and Y and how they relate to Longitude and Latitude.
Start at the far left side of the map and move your cursor horizontally to the right all the way across the map. Observe how the X coordinate changes. The X and Y coordinates are shown in the lower right corner of the map. What happens to the X values?
In this case, the cursor is hovering over southern Alaska.
Notice in the lower right corner of the map view; X: -152.619 Y:64.364.
X is the Longitude and Y is the Latitude.
South and west are indicated with negative values.
A GIS map — is made of layers of geographic information connected to specific places on Earth. GIS layers can be global, regional, or local. They can represent 1) points, such as cities, 2) lines, like rivers and roads, or 3) geographic areas such as states and countries.
To turn a layer on or off, click in the check box next to the name of the layer. The layer will then be displayed on the map.
Click the checkbox next to the US States layer to turn it on.
Currently, the legend of the US States layer is expanded so that the name of every state is displayed. To collapse the legend, click the minus symbol to the left of the layer checkbox. Then use the Zoom In tool to zoom in on North America by clicking on the map.
To the left of the map space is a listing of Layers, called the Table of Contents.
In the Table of Contents, select the Countries layer by clicking and holding its name. Drag the Countries layer down the list and place it at the bottom of the Table of Contents.
Click and hold on the Countries layer in the Table of Contents. Drag it down to the bottom of the list.
This is what the map looks like with the Countries layer at the bottom.
The layer is no longer visible. This is because it is now beneath the Lat / Long layer. If a layer is opaque, as this one is, it can hide other layers. So, in this case, the Lat / Long layer has now hidden the Countries layer.
Turn off the Lat / Long Layer and you will be able to see Countries again.
In the map below, Countries are hidden by Lat / Long.
Turn off Lat / Long and Countries are now visible again.
In this map the Lat / Long layer has been turned off.
Turn the Lat/Long layer back on. Click and drag the Lat/Long layer to the bottom of the Table of Contents.
This is what the map looks like with the Lat / Long layer once again on the bottom.
The data that make up the layers are shown as either points, lines, or polygons. These layers come from shapefiles, a standard GIS data format. (It is also possible to add images to a GIS.) The layers are drawn from the bottom to the top as they appear in the Table of Contents. If not positioned properly, it is possible for some layers to cover up others. In general, polygons should be placed at the bottom, while lines and points should be arranged near the top.
ArcGIS allows you to choose which layer you want to work with from within all tools. If you are asking to find a certain river in your project, just make sure that you choose the rivers layer to look in when asking the software to find the Pearl River for instance. This is the equivalent to making a theme active in other versions of GIS software. This should help simplify the concept of whether a layer is visible or if it is active which is required in other GIS packages. Layers that are turned on or are visible have a check in the box next to their name. More than one layer can be on at a given time, don't forget that some layers can be on top covering other layers when looking for them. Feel free to rearrange the layers to avoid completely covering over as needed.
Turn on the US Rivers layer.
To turn on the US Rivers layer, click once in the box next to its name.
To zoom in on the US Rivers layer, place your mouse over the US Rivers layer and click the right side of your mouse, Choose Zoom to Layer in the window that opens.
What sets a GIS apart is the database of information linked to each layer drawn on the map. This makes it a powerful tool for decision-making and science. The data for each feature displayed on the map can be found in the Attribute Table. This table, or database, contains the geographic records in horizontal rows. The vertical columns, or fields, are the attributes of the data.
In the Attribute Table, click the left most column of the table to select the record on for the NAME Arkansas River. Notice it becomes highlighted in blue in the Table of Contents and in yellow on the map.
Try this with several rivers. The Attribute Table brings up the records of all the rivers and shows you all the information that is available for each record. For example, you can see which river system various rivers are in. The Arkansas River is in the Colorado River System.
Select all the rivers in the Colorado River System.
Open the Attribute Table of US Rivers and right-click on the column that holds the data for the field header entitled SYSTEM. Then select Sort Ascending, scroll down the list to where you see the 4 rivers on the map that are in the Colorado System.
Click on the Identify tool in the toolbar to select it. Use the Identify tool to click on a river on the map to select it. In the pull down menu select the US Rivers as the layer to "identify from:". The selected river will flash green and a results window will open.
Note: 3/15/10 The movies in the page above are ArcGIS movies. AEJEE movies are posted below.
How to download movies
Click the link to go to the SERC media library listing for the movie. The record will open in a new window.
On the SERC media library page, right-click (Win) or control-click (Mac) the link (below the movie on the Flash version pages) to download the movie file to your hard drive.
Download these versions to play on your computer. You'll need an appropriate movie player to view the file, such as Flash Player, Real Player (Mac / Win), or Adobe Media Player.