Transcript Session five: Exploring ArcGIS

RGS-IBG Online CPD course in GIS
Exploring ArcGIS
Session 5
ESRI’s ArcGIS is one of many geographical information
systems (GIS), or GIS software. A GIS allows you to
interactively work with spatial data. ArcGIS is what ESRI
refer to as a suite of products which can be tailored to
your need. The basic version of ArcGIS is what we will be
using in this course and is all the majority of GIS users will
ever need, it is composed of three essential products;
ArcMap, ArcCatalog and ArcToolBox. ArcMap is where you
can see your map data, ArcCatalog allows you to organise
your geographical data (much like Windows Explorer) and
ArcToolBox holds some of the more advanced
geoprocessing tools.
In this short exercise you will become familiar with
ArcMap and begin to understand the building
blocks of a GIS project. The objectives of this
session are to understand the software’s interface
and learn briefly how to load and explore data. In
doing so, you will have integrated a number of
datasets which form the basis of being able to
interrogate data further.
The data you will use are local authority areas and a
small list of point locations of students’ addresses.
Objectives
• Learn how to open ArcMap
• Understand ArcMap’s interface
• Understand the difference between loading
data and loading a project
• Become familiar with exploring data in
ArcMap
• Think Spatially!
Exercise
In this short exercise you will become familiar with ArcMap
and begin to understand the building blocks of a GIS project.
The objectives of this session are to understand the software’s
interface and learn briefly how to load and explore data. In
doing so, you will have integrated a number of datasets which
form the basis of being able to interrogate data further.
The data you will use are local authority areas and a small list
of point locations of students’ addresses. The data has been
created for you and saved as a Project.
Watch the following video, this will explain how to open a
project in ArcMap.
1. Open ArcMap. Go to Start > All Programs >
ArcGIS > ArcMap.
2. A dialogue box will appear. Choose to start using
ArcMap by selecting the ‘A New Empty Map’
option.
3. You will see the following screen. Keep the
following picture as reference, the Table of
contents (TOC), the Data Frame and some of the
tools will be referred to throughout the course.
Open Project
(e.g. a .mxd
file)
Table of
Contents
Add Data (e.g. a
.shp file)
Zoom, change
view and
navigate around
the map
Data
Frame
Identify
Measure
The Table of Contents
5.
6.
7.
An ArcMap project is usually a collection of data. The project file itself is
quite small in storage size, it is simply a collection of pointers to each of
the data files within the project. ArcMap projects have the file extension
.mxd. Now open a pre-saved project as you saw in the video. Click on the
‘Open Project’ folder. Navigate to where you saved the course data.
Open the ‘5 Exploring GIS Data’ folder. You should see a project called
‘Students.mxd’, open this.
You will see a map of London’s local authorities from 2003 in the Data
Frame. In the TOC you will see a layer called LondonBoroughs. Press on
the tick to the left of this layer. London disappears! It is from the TOC
you control the layers that are seen by simply turning the tick on and off.
Now click and hold down on where it says LondonBoroughs in the TOC.
Drag it above Students. The students have now disappeared. Imagine
looking down from the top of the TOC, the first layer you see is the first
layer you would see looking down on the Earth’s surface.
Zooming and Navigation
7.
8.
Now explore the zooming functionality. There are four buttons to
use. Two magnifying glasses, one with a minus symbol one with a
plus; and two crosses, one with arrows pointing outwards and the
other with arrows pointing inwards. The two crosses are known as
‘fixed zoom’ buttons, press them and notice how you can zoom in
and out in increments. The magnifying glasses instead allow you
to direct your zoom to a specific area.
Moving about the map. The hand is called the ‘pan’ button. This
allows you to move the map to centre it where you choose. You
will also notice two arrow buttons, one pointing left, the other
right. These are like the ‘back’ and ‘forward’ buttons in Internet
Explorer. They allow you to move back to a past map view before
zooming in for example. Finally the button with a picture of the
Earth on it. This is the ‘Full Extent’ button and it re-centres the
view to include all the data.
Some Simple Functions
9.
Press the measuring tool button (refer back to the screen map above). A
small box will pop up with a number of options. Press the small down
arrow button and change the distance units to kilometres. The buttons
on the left allow you to measure a line, an area or a feature. Experiment
with these. Tip: the line measuring tool allows you to measure segments
as well as a cumulative distance. Press to start, press again for a
segment, press again for another segment, and double click to finish.
The ‘Measure a feature’ tool allows you to measure the actual features
on the map, you only need to press this tool once, e.g. within a local
authority.
10. The Identify tool operates the same way as the ‘Measure a Feature’.
Press the Identify tool in a local authority of London. A box opens up
showing you the attributes, or characteristics of a particular feature. You
can see that GIS is not just about maps. Software such as ArcGIS is as
much about the data behind the maps. You will explore this further
another time.
Adding Data
10. Data for ArcMap comes in a variety of formats, one of the most
common being a shapefile which has the extension .shp.
Shapefiles are composed of at least three separate files however
using ArcMap you will see what appears to be just one file.
Having watched the video now add the location of the Royal
Geographical Society to your map. Click on the ‘Add Data’ button
and navigate to your personal folder. Open the RGS.shp file. It
should appear as a small point near the centre of the map, you
will learn in a later exercise to change the appearance of data to
make it stand out more.
(If you are unable to locate your data you may need to ‘Connect
to Folder’ for which video instructions follow)
11. Now explore the aspatial, or attribute data of the local authority
and student datasets. Right click on either of the layers and click
on ‘open attribute table’. In both datasets you will see a ‘name’
attribute followed by some other attributes. In the local
authorities data you will see some population data, in the student
data you will see both name and gender data. You should notice
that this is the same data the Identify tool was highlighting earlier,
the difference here being you can see the whole layer’s (all the
local authorities) data at the same time. Again this highlights that
GIS is not just about maps. Close the tables.
12. Save the project by pressing the ‘disc’ button. Next time you open
this project it will include the Royal Geographical Society.
Summary
You should now know;
• How to open an ArcMap project
• How to add data to an ArcMap project
• How to use some of the simple functions
• That GIS is not just about maps, but data too
Further Exercise
You have now opened a project, integrated a further dataset and have quickly
looked at the data contained within the GIS project. Think about how this sort
of data can be used further and what sort of spatial problems it can help us
understand.