ArcGis Concepts

8/11/2019 ArcGis Concepts

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Lecture 3

ArcGIS Desktop - Spatial data -in, out and shake it all about!

Geog5040: Using and adapting ArcGIS


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Last week

A first lookat ArcGIS

What IS ArcGIS?

Where do I findhelp?

How is datastored in ArcGIS?

Who uses ArcGIS?

Working withCoveragesand command line

ArcWorkstationArcGIS

ArcCatalogArcMapArcToolbox

BooksArcGIS Desktop helpArcInfo WorkstationArcDocStaff

Each other

Discussion on

experience andpossible users

Concentrated onVector datamodel:ShapefilesGeodatabasesCoverages

More detail oncoverages

Brief look at howto use ArcEdit


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Overview of Weeks 2-6 of GEOG5040

USING ARCGIS

Week 2: A first look at ArcGIS and

ArcInfoWorkstation

Week 3:Spatial Data

in, outand shake it all

about!

Week 5:Spatial

Manipulation&

Analysis Week 4:Tables, Querying,Displaying and

Presentation

Week 6:Rasters &Surfaces

Weeks 7-11: Adapting ArcGIS

(with Dr Andy Evans)


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Aims and objectives of this lectureThis lecture/workshop aims to :

Introduce you to ArcGIS Desktop, in particular ArcCatalog, ArcMap and ArcToolboxExplore different methods of getting spatial datainto ArcGIS

Give you the opportunity to use the Editor ToolbarGuide you on exporting your data Provide support to start building a geodatabase

Upon completion of this lecture/workshop you should:Be familiar with ArcGIS Desktop basicsHave an appreciation of the different means ofinputting and exporting spatial dataHave started to build a geodatabase


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Week 3: Data In, out and shake itall about!

Spatial d ata in,out and shake

it all about!

What ArcGISapplications do I

need to use?

How do Ichange/edit spatial

datawithin ArcGIS?How do I export

my data?

How do I build aGeodatabase?

How do I get spatialdata in?


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What ArcGIS applications do I needto use?

In order to get data into ArcGIS, edit andexport we need to be familiar withArcCatalog and ArcMap and ArcToolboxFirst of all we will quickly take a look at theinterfaces for these applications anddiscuss what each one does.


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What do we do in ArcCatalog?

Manage geographic dataCopy, move, delete dataConnect to drives on your computerSearch for data on your drives or across anetworkView/add/edit metadataDrag data into ArcMapExport data


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ArcCatalog interface

CatalogTree

Catalog display(Preview mode)

Geography

selected

Toolbars


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ArcCatalog interface Catalog display(Preview mode)

Table selected


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What do we do in ArcMap

Displaying map dataNavigating/exploring a map

Looking at feature attributesEditing features and attributesQuery attributes

Analyse spatial relationshipsDesign map layouts


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ArcMap interface

Mapdisplay

Table ofcontents


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ArcToolbox interfaceArcCatalog

ArcMap

ArcToolkitwindow


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Extensions

Extend thecapabilities of ArcGISwith a number of

products Add from the Toolsmenu in ArcCatalogor ArcMap

Allows selection ofproducts (subject tolicense)


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Toolbars for extensions

Toolbars for these extensions do notautomatically open. Use View > Toolbars toopen (in ArcMap)


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Activity 1 - Extensions

Not all of ArcGIS's capabilities can automatically be seen. Some ofthe tools have to be enabled (as long as the University has thelicence for it). For example, if you wish to use the Spatial Analysttools from ArcToolbox (third tool from bottom when you look in

ArcToolbox), none of the tools work unless Spatial Analyst has beenenabled.Try this now....click on any of the tools within Spatial Analyst...dothey open up a dialog box or does it come up with an error messagesaying the licence is not available? If the former then the tool hasalready been enabled but if the latter then you should enable thisnow.

Add in any extensions that the University has a licence for that arenot already enabled. When that is done, make the Network Analystand Spatial Analyst toolbars visible. You do not need to leave thesetoolbars visible if you don't want to.


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How do I get spatial data in?

Spatial data in,out and shake

it all about!

What ArcGIS

applications do Ineed to use?

How do Ichange/edit data

within ArcGIS?How do I exportmy data?

Networks. How do I get spatialdata in?


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Getting geographical data in

Creating new dataImporting shapefiles, coverages andgeodatabases.Importing text files.Importing other formats.

Importing from web services.


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Creating new data

DigitisingProduces vector dataUsually produced from paper maps, aerial

photos or satellite imagesHeads-up digitising

Digitise image on computer screenManual adding e.g. from raw coordinates. ArcGISallows you to create shapes or specify angles andlengths of line segments and whether they areparallel or perpendicular to other segments


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Importing

Right-clicking on aWorkspace,Geodatabase or FeatureDataset brings up importand export options, soyou don t have to buildGeodatabases fromscratch.


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Importing other formats ArcToolbox has a whole setof tools for conversion.

In ArcCatalog there is an

ArcView 8x Toolbar withConversion Tools

MapManager (accessed viaa toolbar in ArcCatalog orfrom the Start menu)

NTF converterOS MasterMap data converter


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Importing text files(Coverages)

ArcGIS can import ASCII textfiles ( American S tandard Codefor Information Interchange).

ArcToolbox Generate toCoverage Wizard ..

NB: Generate files onlyinclude geography, not

attributes.


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Importing from web services

Web services: the Next Big Thing.Data storehouses you connect via a menu on yourGIS, they download the data to you. You don t save itlocally.

For example, ESRI s online data warehouse, Geography Network(http://www.geographynetwork.com/)

Ultimately online GIS will do the analysis you just getthe results.


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Geography Network

Pick locality, dataset and it downloads the data fromthe website into your application.


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Metadata

What is metadata?Data about dataWho created itWhere it came fromCoordinate systemWhat fields in attribute tables mean

Why is it important?Without metadata, data is uselessDealing with undocumented data can be

frustrating.


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Viewing metadata

Tabs and links in ArcCatalog


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Editing metadata

Editing metadata is done via themetadata toolbar

Can select: Stylesheet Edit metadata

Metadata properties Create/update metadata Import metadata

Export metadata


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How do I change/edit spatial datawithin ArcGIS?

Spatial d ata -in,

out and shakeit all about!

What ArcGIS


How do Ichange/edit spatial

datawithin ArcGIS?

How do I exportmy data?


How do I get datain?


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Tasks: Modify features etc

There s a few additionalmenu items that mighthelp you, if your topologydoesn t clean or you needto edit your data.These are on the Task drop down list of theEditor Toolbar.


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Editing Topological features

Shared features have boundaries or nodes in commonIf you change a boundary between two polygons whichshare that boundary then you have to edit the firstpolygon and then the second, using snapping to align

accurately. ArcGIS has a special tool for editing of shared features:Topology Edit tool (on the Topology toolbar)Then use the Topology tasks from the Task bar


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Autocomplete Polygon

You can also use AutoComplete Polygon from the task list with the sketch tool to addPolygons with shared boundaries.


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How do I export data from ArcGIS?

Data in,out and shake

it all about!

What ArcGISapplications do I

need to use?


within ArcGIS?How do I exportmy data?




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Activity 2 Editing a polygon shapefileNow you can have a play with editing a shapefile.

Open the wyorks shapefile (showing the polygons of West Yorkshire) from Practical 1 in ArcMap. Make sure the Editor Toolbar is visible (use View > Toolbars..to add it if necessary).When you wish to start editing click on the little arrow next to 'Editor' on the toolbar and select'Start Editing'. This makes the toolbar 'live and areas which were previously greyed out orunselectable can now be selected. [Note: This shapefile may be read only (giving you an errormessage that you don't have permission to edit it) in which case you need to deselect the ticknext to Read- only in the file s Properties.] Have a look at the tools on the editor toolbar and check out what they do. Have a look at thevarious tasks that are now available to you. Note that not all tasks may work, especially as youare working with a shapefile and you only have polygons to work with (so editing functions likeextend and trim which are designed to work with lines/arcs won't work for polygons) but you cancreate new features, modify features, move them or split polygons.

An example may be that you wish to modify a polygon. Select the task to be Modify features,

click on the Edit tool (the arrow next to the Editor drop down menu, click on a polygon and youwill see the vertices highlighted. You can then drag and move those vertices to create a newshape. When you have moved the vertices, right click in the map display area and select FinishSketch. Your polygon should change.See what else you can do. When you have finished select 'Stop Editing' from the Editor dropdown menu. Select No when asked if you wish to save changes.


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How do I build a Geodatabase?

Data in,out and shake

it all about!

What ArcGIS



within ArcGIS?How do I export

my data?




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GeodatabasesNew ArcDesktop data format.

The future for ArcGIS.

Like a Coverage only stored in an Object OrientatedDatabase.

Local or Personal Geodatabases vs. SDE Geodatabasesshared on a network.

SDE databases can be on ArcSDE servers or most otherdatabases. They have locking and versioning to resolveconflicts if more than one person edits a Feature.


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GeodatabasesCan build them from scratch, import from other formatsor build using drawings.

Keep strict Topological and Data Item constraints onFeatures.

Build Topology and confirm Features have appropriatedata as they are edited.

Because of this, are used as the basis of Network Analysis.

Geodatabase Feature Dataset Feature Class Features

Workspace Coverage Arcs, Polygons etc. Features


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Object Orientated Databases

Each feature is an Object stored in the Geodatabase.Each Feature is of a certain predefined type, orClass.You can define your own classes, and inheritproperties from standard classes.When your classes inherit from another class, theypick up all the Classes Attributes.Classes inheriting from another are known asSubclasses of a Superclass.

ESRI Simple EdgeFeature

integer : length

Building

integer : people

House

Has length and peopleAlso has

length


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Constraints

Geographical.Class and data types.

Variable ranges or categories.


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Example

Whereas previously you d make an Arc for a road, you cannow make a Road class from the Simple Edge Feature superclass.

Constrain the Road so it must have a Surface type variable picked from a list.

Subclass Road to make a Motorway class, with a Number variable which is constrained between 1 and 999.


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Benefits of Geodatabase data model

All data stored centrally in Access databaseData entry and editing is more accurate inputvalidated

Data objects more intuitive roads, lakes ratherthan lines and polygonsFeatures have richer context define a featuresquality as well as its context with other features

Better mapsMany users can edit geographical datasimultaneously conflicts can be reconciled

B ildi G d t b f


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Building a Geodatabase fromscratch

First decide your requirements. Many parts ofthe creation process cannot be undone later, soget it right first time.

What types of data do you want and whatconstraints?What geographical area do you need?

Are you going to do analysis on the data?

Build the Geodatabase in ArcCatalog.


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Table of Contents

You should end up with something like thefollowing.

Geodatabase

FeatureDataset

FeatureClass


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Benefits of Geodatabase data model

All data stored centrally in Access databaseData entry and editing is more accurate inputvalidated

Data objects more intuitive roads, lakes ratherthan lines and polygonsFeatures have richer context define a featuresquality as well as its context with other features

Better mapsMany users can edit geographical datasimultaneously conflicts can be reconciled


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Building the Geodatabase

Right-click on the Workspace and pick New Unless a server is running ArcSDE, you ll only get thechance to create a Personal Geodatabase .

To connect to anexisting SDEdatabase, useDatabase

Connections .


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Building the GeodatabaseYou set constraints

by creating AttributeDomains at theGeodatabase levelin its Properties .

These can beranges or codedvalues (categories)data must fall in.

These are thenapplied to specificFeature classes.

A ib D i


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Attribute DomainsMaximum and Minimum range, or build codes forcategories with associated text descriptions.

A Default Value for new Features.

Split policy: if a Feature is split, how should the Attributedata be handled in each new Feature?

Each gets the default, duplicates the original, or is theoriginal value split on the basis of the divided length/area.

Merge policy: if two Features joined, how should the Attribute data be kept?

Feature gets the sum of the original, the default, or alength/area weighted average.


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Feature Dataset

Right-click

Geodatabase > New > Feature Dataset .

A collection ofFeatures that share aSpatial Reference,i.e. area andcoordinate system.Set this with the Edit button.

Give the Dataset a max/min area

and Select a Projection System.


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Feature ClassesRight-click Feature Dataset > New > Feature Class

Choose a name and set the field.


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Feature Classes: Constraints Add new Field.For each pick an

Alias (alternativename - can includespaces), a DefaultValue, and an

Attribute Domain ifyou want constraint.Field Propertieschange when youclick on a Field

Name.


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Summary

Geodatabases are a new, highly controlleddata storage technique.When you build one, you can set AttributeDomains which are constraints that can beapplied to Features.You build a Feature Dataset for a particulararea / spatial reference.

You design Feature Classes e.g. Roads andset their constraints.

ld l


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Activity 3 Build a personalgeodatabase

Using the instructions given athttp://www.geog.leeds.ac.uk/courses/postgrad/geog5040/lecture3/Pract3_08/index.html , start to

build a geodatabase.Refer also, to the next 10 slides for furtherinformation.

k l d d
http://www.geog.leeds.ac.uk/courses/postgrad/geog5040/lecture3/Pract3_08/2.htmlhttp://www.geog.leeds.ac.uk/courses/postgrad/geog5040/lecture3/Pract3_08/2.htmlhttp://www.geog.leeds.ac.uk/courses/postgrad/geog5040/lecture3/Pract3_08/2.htmlhttp://www.geog.leeds.ac.uk/courses/postgrad/geog5040/lecture3/Pract3_08/2.html


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Week 3: Spatial data In, out andshake it all about!

Spatial d ata -in,out and shake

it all about!

What ArcGISapplications do Ineed to use?

How do I

change/edit datawithin ArcGIS?How do I exportmy data?



ArcCatalog, ArcMap, ArcToolbox

Digitising,importing,

joining attributedata, geocoding

The editortoolbar, editingtables

Variousformats

accessed fromcontext menu

Practical exercisebuilding a geodatabase


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Practical

Build further the personal geodatabasestarted in the lectureUsing ArcMap and the Editor Toolbar,create data in your geodatabaseWe will revisit this geodatabase in Week 5and explore network analysis


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Practical and Assignment

This practical will give you experience in:Building geodatabasesUsing the Editor Toolbar to add new data andmanipulate data

Assignment (in brief see VLE for full details)Build the geodatabase and add some features to it.

Create some metadata for your Sewer FeatureDatasetSend me your geodatabase for assessment.


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Next week

TablesQueryingDisplaying dataPresenting data

Documents

ArcGis Concepts