GIS 215 - GIS Data Models

Module 10 - GPS with Trimble: Getting started

2011-04-26T09:30:00.000-04:00

LEARNING OBJECTIVES

Utilize Trimble software and hardware to collect GPS data
Discuss GPS Pathfinder Office utilities
Build a Data Dictionary in GPS Pathfinder Office
Perform mission planning for GPS data collection
Describe the rigorous data collection parameters utilized in TerraSync to ensure sub-meter (sub-foot) accuracy.
Set up data collection parameters in TerraSync
Differentially correct GPS data using Pathfinder Office
Convert GPS data to shapefile format

TERMS TO KNOW

MS Active Sync
.ssf
.cor
Differential Correction
WAAS
Post-process
TerraSync
GPS Pathfinder Office
Multipath
PDOP
SNR
Elevation mask

DISCUSSION

ACTIVE LEARNING EXERCISE

STEPS TO A TRIMBLE GPS FIELD SURVEY PROJECT

Project setup (Pathfinder Office)
Database design / Field Reconnaissance (Pathfinder Office)
Project / Database transfer to TerraSync
TerraSync settings and set-up
Field data collection
Post-process differential correction
Export to GIS

ACTIVE LEARNING EXERCISE

Steps 1 and 2 - Project set-up, designing your database, and buidling a data dictionary

http://docs.google.com/Doc?id=ddh8bbwd_652gtttttgv

Steps 3, 4 and 5 - Tranfering Data, Mission Planning and more ...

http://docs.google.com/Doc?id=ddh8bbwd_654fm9927dj
connect GPS
conduct mission planning
explore GPS Pathinder Office utilities

Collect GPS data using TerraSync
Transfer and differentially correct GPS data
GeoXT (TerraSync) QuickStart Guide

SUPPLEMENTAL RESOURCES

HOMEWORK

TerraSync Evaluation Demo for your desktop PC

Follow this Evaluation Guide using the Demo above loaded on your desktop

Module 9: GPS: The Global Positioning System

2011-04-19T08:01:00.002-04:00

LEARNING OBJECTIVES

Identify the 3 segments of GPS
List the acceptable number of satellites (SV's - space vehicles) for an accurate 3D position
List and explain sources of error in the GPS system
Explain why satellites are provide a good system for located positions on the earth
Define trilateration
Discuss how the distance from the satellite to the GPS receiver is determined.
Describe the almanac and what it is used for
Define ephemeris information and what it is used for
Define autonomous GPS
Describe differential GPS (SBAS, Post-processing)
Describe the critical software settings in Trimble TerraSync

GENERAL GPS TERMS TO KNOW

GPS - Global Positioning System
NAVSTAR - Navigation Satellite Timing and Ranging
Almanc
Ephemeris
Accuracy
DGPS - Differential GPS
SBAS - Satellite Based Augmentation System
WAAS - Wide Area Augmentation System
Selective availability
Mulitpath
Obstructions
Atmospheric Delay

RECREATION GRADE GPS TERMS TO KNOW

tracks
waypoints
gpx
kml
Garmin MapSource
GPSUtility
GPS Babel
GPS Visualizer - website based on GPS Babel
DNR Garmin

DISCUSSION

GPS PowerPoint Supplement

- refresh the page if the file does not download

ACTIVE LEARNING EXERCISE

Utilize Garmin recreation grade GPS to collect waypoints and tracks around campus. Incorporate this data into Google Earth (KML) and ArcGIS (shapefile).

more ...

more Module 9 - GPS - Recreation Grade Lab

2011-04-19T08:00:00.000-04:00

INTRODUCTION

'Recreation grade' GPS receivers provide accurate data collection tools for a fraction of the cost of 'Professional grade' GPS tools. We will look at several Garmin GPS receivers during this class. There are many other manufacturers of recreation grade GPS units like Magellan that have similar functionality but we will stick to Garmins since that is what we have a school.

LEARNING OBJECTIVES

Describe the GPX format
Utilize the main pages on a 'recreation' grade GPS unit (one of the school Garmins or your own)

Satellite page
Map page
Compass page
Main menu

Define waypoint
Define track
Modify GPS settings through setup menu

Set coordinate system
Activate WAAS

Create waypoints
Save tracks
View map
View satellites
Navigate to waypoint
Connect to GPS using several FREE utitities
Utilize GPSUtility and Garmin MapSource to transfer GPS data to desktop computer
Display GPS data in Google Earth and ArcMap

LEARNING RESOURCES

GENERAL GPS

About GPX

About KML

DNR Garmin

GARMIN RESOURCES
Garmin 60cs on Garmin website
Garmin 60cs 60c review - great screen shots
Garmin 60cs manual
Garmin MapSource

Recreation Grade GPS vs Professional Grade GPS

HOMEWORK

Recreation-grade GPS assignment

http://docs.google.com/Doc?docid=ddh8bbwd_651d6b77kzr&hl=en

Module 8 - Database design and Final Project

2011-03-29T07:03:00.001-04:00

Review this supplemental document on geodatabase design as well as looking back over your lecture notes and the PowerPoint from our geodatabase design discussion.

Begin to explore this Final Project for this class.

Module 7 - LiDAR

2011-03-22T05:55:00.003-04:00

Lidar 101

Another Lidar 101

ACTIVE LEARNING EXERCISE

LiDAR in ArcMap - http://docs.google.com/Doc?id=ddh8bbwd_925h6bz6chc&hl=en

LIDAR RESOURCES

CLICK -Center for LIDAR Information Coordination and Knowledge
http://lidar.cr.usgs.gov/

Back to the Campus Geodatabase Project

2011-03-15T17:26:00.004-04:00

Continue with steps 6-9 of the Campus Geodatabase Project.

http://docs.google.com/View?id=ddh8bbwd_673hqvjnbg4

Topology in ArcGIS

2011-03-13T12:43:00.001-04:00

LEARNING OBJECTIVES

Define topology
Describe map topology
Describe geodatabase topology
Describe coincidence
Explain how topology helps with analysis and data integrity
Define cluster tolerance
Define ranks in a topology
List several topology rules
Describe topology validation
List several types of topology errors
Discuss 2 ways topology errors may be fixed.

TERMS TO KNOW

topology
map topology
geodatabase topology
connectivity
adjacency
containment
validation
topology errors
data integrity
coincidence
cluster tolerance
ranks

CLASS DISCUSSION

In ArcGIS there are 2 types of topology.

Map Topology: Available at the ArcView license. Used during an edit session to ensure coincident features maintain coincidence while editing.

Geodatabase Topology: Available only with ArcEditor and ArcInfo licenses. Powerful rule based topology that help with data validation.

** See supplement resources below for more information on both these topics.

Working with Geodatabase Topology - ESRI LIVE Training Seminar (recorded at an earlier date)

ACTIVE LEARNING EXERCISE

Creating and Editing Geodatabase Topology with ArcGIS Desktop (for ArcEditor and ArcInfo)

SUPPLEMENTAL RESOURCES

fom the ESRI WebHelp
About Topology
Basics of Map Topology
Topology in ArcGIS - Geodatabase Topology
Geodatabase Topology Rules

Module 5 - The geodatabase lecture - Part 2

2011-03-01T07:01:00.002-05:00

LEARNING OBJECTIVES

Describe how relationships work in the geodatabase
Describe the different ways information is validated in the geodatabase
Describe topology
Describe map topology
Describe geodatabase topology

DISCUSSION

Class discussion (slides 44 -61) - Advanced Functions of the Geodatabase - PowerPoint Supplement

Class Discussion - Topology

ESRI Webhelp:

ACTIVE LEARNING EXERCISE

Module 4: Creating, Editing and Managing Geodatabases for ArcGIS Desktop

Virtual Campus Course is due before class next week.

STUDY QUESTIONS

What are the 3 types of relationships that can exist in the geodatabase?
What are the 4 types of cardinality that can exist in the geodatabase?
Describe relationship classes.
List and describe the 4 types of validation rules.

Module 4 - The Geodatabase

2011-02-21T08:46:00.004-05:00

INTRODUCTION

We will be introducing the Geodatabase, what they are comprised of and the different types of geodatabases available at 9.3

LEARNING OBJECTIVES

Define the geodatabase
List the elements of the geodatabase
Describe how the geodatabase is different that other spatial data formats in it's handling of 'real-world' behaviors
What is an 'object' in a geodatabse?
Describe a domain in depth
Describe what domain split and merge policies are
Describe a subtype
Describe a feature class
Describe an object class
describe a feature dataset

TERMS TO KNOW

Geographic database
Geodatabase
object-relational
object
File Geodatabse
Personal geodatabase
Scalable or ArcSDE geodatabase
Relational Database Management System (RDBMS)
domains
subtypes
feature class
feature dataset

READING ASSIGNMENT

Class discussion (slides 1 - 43) - Introduction to the Geodatabase - PowerPoint Supplement

ESRI Webhelp:

An overview of the geodatabase

An overview of the spatial reference

An overview of working with feature datasets

An overview of attribute domains

An overview of subtypes

ACTIVE LEARNING EXERCISE

Module 2&3: Creating, Editing and Managing Geodatabases for ArcGIS Desktop

Virtual Campus Module 1: Creating, Editing and Managing Geodatabase

2011-02-15T19:19:00.003-05:00

Due next week:

Module 1: Creating, Editing and Managing Geodatabases.

Instructions:

Go to http://training.esri.com
Login (create an account if you do not have one)
Go to My Training
Go to My Virtual Campus Courses
Start a New Course
Enter the code you got in class
Complete Module 1
I will look at it next week at the beginning of class.

Lab Test: Working with CAD data

2011-02-15T08:00:00.000-05:00

Follow the instructions below to complete the lab test.

Get the test and files here

Module 3 - CAD data in ArcGIS | Campus Mapping Project

2011-02-01T07:33:00.000-05:00

LEARNING OBJECTIVES

Describe CAD data
Discuss the differences in GIS and CAD data
Define CAD dataset layer
Define CAD drawing layer
List the 3 most commonly used CAD formats
Describe the contents of a CAD drawing
Define world files and describe how they work
Georeference CAD data

TERMS TO KNOW

CAD
CAD feature datasets
CAD drawing datasets
world file
projection file
georeferencing
transformation
control points
link table

DISCUSSION

Introduction to CAD data in ArcGIS

ACTIVE LEARNING EXERCISE

A-B Tech Asheville Campus Geodatabase Project

Module 2 - Introduction to data models / data types / the geodatabase

2011-01-24T06:51:00.000-05:00

LEARNING OBJECTIVES

Describe the Coverage data format
Describe the Shapefile data format
Describe the Geodatabase data format
Describe the CAD data format
Compare and conrast each of the above data formats
List several other data formats used for storing geographic information

TERMS TO KNOW

Describe the raster data model
Describe the vector data model
Define data format
Coverage
Shapefile
Geodatabase
CAD
feature class
feature dataset
stored / shared topology
coincident features

READING ASSIGNMENT

Modeling Our World - Chapter 4 and the ESRI support pages below

PowerPoint Supplement

From the ESRI support pages:

ACTIVE LEARNING EXERCISE

Working with different data formats exercise

The data for this exercise can be found on the server: H:\GIS\GIS_classes\GIS215\SpatialDataFormats

Copy it to your flash drive to complete this exercise.

STUDY QUESTIONS

List 4 disadvantages of the CAD data format
What is a geo-relational data model?
What are 3 disadvantages to the ArcInfo Coverage?
Describe the shapefile
How many files must be present for a shapefile to be considered whole?
What are 3 disadvantages to the shapefile?
Describe the geodatabase in 1 sentence.
List the geodatabase types.
What type of information is modeled well using raster data?
What type of information is modeled well using vector data?

HOMEWORK ... YES HOMEWORK

Working with CAD data in ArcGIS 9.2

Module 1: Class Introduction / Review ArcGIS / Data Models / Project 1

2011-01-10T13:21:00.003-05:00

COURSE INTRODUCTION

LEARNING OBJECTIVES

Review of ArcGIS and GIS 111 (follow the link)
Define data model
Define data format
Describe the differences and similarities of the data models and data formats
List 2 data formats

TERMS TO KNOW

Data model
Coverage
Shapefile
Geodatabase
CAD
Raster
Vector

READING ASSIGNMENT

Modeling Our World - Preface and Chapter 1 (for next week)

PowerPoint Supplemements (refresh page if download does not begin)

Lecture 1 - Data Models and Data Formats (see video of lecture/PPT here)

ACTIVE LEARNING EXERCISE

Project 1: Building a Buncombe County Geodatabase

https://docs.google.com/document/pub?id=1Du6NsWvB_BfCdI-kSRHapy9hj9Sa_OBjz__svq4anu8

HOMEWORK

Finish Project 1 for next week.

Test 3 Study Guide - GPS

2010-12-13T10:59:00.000-05:00

Access study guide here

Module 6 - Database Design

2010-10-17T18:04:00.001-04:00

Test 1 Review

2010-09-15T08:00:00.001-04:00

Test 1 next week -

The test format will be multiple choice, true/false, and discussion. It will cover Chapters 1and 3 in the book, working with CAD data and anything else we have covered so far this semester.

Get the study guide here

Next generation GPS to be more accurate

2010-05-07T11:13:00.003-04:00

Looks like the new IIF satellites will have accuracies down to 3 feet in real-time. See the Wired article on this from yesterday.

Test 2 Review

2010-03-23T20:57:00.002-04:00

Test 2 Review

Describe in detail the 3 types of geodatabases
Describe the geodatabase and it's major components
What is SDE?
Define domains. Describe both types and what fields they may be applied to.
Describe subtypes. Why use them?
What is a relationship class and what differentiates them from build relationships between tables in ArcMap.
Compare and contrast raster datasets and raster catalogs.
What is a feature class?
What is an object class?
What is a feature dataset? Describe 2 reasons we may use them.
What is topology, in general?
Why is topology important?
Compare and contrast map topology and geodatabase topology. IN DEPTH
Describe coincidence and clucster tolerance.
Explain how topology helps with analysis and data integrit.
Define ranks in a topology
Describe several topology rules
Describe topology validation
List several types of topology errors.
Describe the steps to designing a geodatabase
Describe why geodatabase design is important
How can existing data models help your design?

Trimble GPS video

2009-05-05T20:59:00.001-04:00

Record your screencast online

Module 8 - Geocoding

2009-04-07T14:16:00.005-04:00

INTRODUCTION

Geocoding is the process of creating geographic representations (usually points) from descriptions of locations (typically addresses, coordinates, zipcodes ...) in a table.

LEARNING OBJECTIVES

Define geocoding
List the 3 required elements to perform geocoding in ArcGIS
What is reference data?
Geocode addresses in ArcGIS

TERMS TO KNOW

geocode
address match
reference data
address locator

READING ASSIGNMENT

Download Geocoding - PowerPoint Supplement

Harvard University Geocoding Best Practices

Plus the links in the Active Learning Exercise to the online help

ACTIVE LEARNING EXERCISE

Geocoding Exercise

STUDY QUESTIONS

What are several reasons an address may not match during the geocoding process?
What is reference data and list a couple types
What is geocoding
What is an address locator
How does composite geocoding work?

Student information needed please

2009-02-02T18:01:00.003-05:00

Please fill out this form with your contact information. It is imperative that you do this now so that I have your contact information in case we miss school this week due to weather. If school is cancelled due to weather, I will be emailing everyone in the class with instructions on what you are resonsible for by the next class. This information will be posted here on the blog.

Recreation grade GPS assignment

2008-12-03T07:21:00.005-05:00

Get the assignment below ...

http://docs.google.com/Doc?id=ddh8bbwd_651d6b77kzr

Geodatabase design and topology

2008-11-17T09:41:00.001-05:00

Designing Geodatabases

Topology in ArcGIS Desktop Help

Topology Rules Poster

Geodatabase support outside of ESRI

2008-11-06T12:46:00.001-05:00

http://technology.slashgeo.org/technology/08/11/06/1427221.shtml

Project work

2008-04-08T16:24:00.003-04:00

ask all the questions you can and get your geodatabase shaped up... we are running out of time...

We need to jump into the wonderful world of Global Positioning Systems.

Class 10 - Geocoding API's and Project Work

2008-03-18T20:56:00.001-04:00

http://www.batchgeocode.com

ABTECH student data...

http://www.batchgeocode.com/map/?i=fa0f74e82a9b0af45ba1b5b9e1088927

Class 7 - Starting you geodatabase

2008-02-20T13:09:00.004-05:00

We will be doing an 'out of class' assignment this week since I am traveling to Valladolid, Mexico for a school trip. Please follow these directions as closely as possible.

FIRST: Prepare

Read Chapter 12 - Geodatabase Design Guide - Modeling Our World
Read An Overview of Geodatabase Design from the ESRI WebHelp
Explore some existed ESRI Data Models (templates you could use or modify)
Consider these design tips
Explore these design steps

SECOND: Document your design - 'Design Guide'. Create some type of document (Word, Excel, Visio, FreeMind) to document your database design. Make sure to include:

Purpose of the database: What functions do you want the database to perform. What analysis will you do with it? What kind of maps will you make?

Included layers: What kinds of layers are required for your geodatabase to perform the functions and operations you wish?

For each layer, include the geometry type (point, line, poly) if vector or the type of raster data.
Include the attributes that might be necessary for your geodatabase feature classes.
Give some examples of how you might validate the attributes through domains
Give some examples of how you might better classify your data using subtypes
List what feature classes my be organized either thematically or spatially in feature datasets
What will be the projection/spatial reference of your feature classes?
This information on modeling feature classes will be helpful to read.

Other information: What other information (non-spatial) will need to included in your database?

THIRD: Research data availability

Conduct internet searches to find existing digital datasets to include in your geodatabase
Describe data you may need to create

FOURTH: Create 'test' geodatabase

Create a file based geodatabase
Incorporate an data you have located into the geodatabase
Keep them as simple feature classes for now but be thinking about how to build more functionality into geodatabase. That's next!

!!! TURN IN NEXT WEEK !!!

Your geodatabase
Your design guide

Lab Test 1 Review

2008-02-05T18:44:00.001-05:00

Georeference CAD data
Save world files
Creating geodatabases
Select data based on criteria (select by attributes)
Convert CAD feature classes to Geodatabase feature classes

Differential Correction

2007-12-03T11:39:00.000-05:00

Autonomous GPS - no correction. +/- 10 meter

Differential GPS
-real-time- Radio Beacon / SBAS / Post-processing

GPS data collection with Trimble TerraSync and the GeoXT

2007-11-27T22:02:00.001-05:00

Last class we created a data dictionary to use during our field data collection. Allen Instruments has a great operational instruction document for the GeoXT and TerraSync. It is short and to the point. It should not be used instead of the Trimble TerraSync Operation Guide by it is a great field guide. See the Trimble TerraSync Operation Guide for more in-depth instructions.

Lab Quiz

2007-11-05T10:41:00.000-05:00

Wednesday, November 7th, 2007

To successfully complete the lab quiz, you will need to do the following at a minimum.

Create a file-based geodatabase
Import a CAD feature class into the geodatabase
Create a new feature class in the geodatabase
Add and/or delete fields from the above feature classes
Add domains (range and coded valule) to the geodatabase
Apply domains and defaults to the feature class fields
Create features by editing in ArcMap

Subtypes and domains

2007-11-05T10:27:00.000-05:00

Create a sidewalks feature class. Polygon / import spatial reference from other campus data.
Add fields for Width (integer), Material (Integer), and Condition (Text)
Add coded value domains to the geodatabase - Width (2,4,6), Material ( 1= Concrete, 2 = Asphault, 3 = Gravel). Condition (Good, Fair, Poor)
Apply domains to fields
Create subtype for Material - Default concrete
Apply default values and domains to subtypes (Concrete- condition = Good, width = 4)(Asphault- condition = Fair, width = 4)(Gravel- condition = Poor, width = 2)
Go into ArcMap, add sidewalks and start editing. Notice the functionality subtypes and domains give to the editing process.

Domains and more

2007-10-29T11:40:00.000-04:00

class Thursday, October 25th, 2007

Demonstrate editing techniques - cutting polygons and auto-complete
Add new fields to building layer to store building floors and height
Adding values to attribute tables
Create range domain on floors field (1-5)
Validating range domains

More campus ...

2007-10-16T20:44:00.000-04:00

Building polylines or polygons? Yeah, you guessed it -polygons. So, how do we go from the CAD polylines to polygons?

http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?id=1535&pid=1526&topicname=Feature_To_Polygon_(Data_Management)

A great tool available at the Arc/Info license called Feature to Polygon. Check it out the screen shot.

Another great tool, if you did not have Arc/Info is an extension for the software called XTools Pro.

It has a lot of great free functionality but if you plan to use it past the evaluation period you'll need to buy it. This extension has all kinds of feature conversions, table operations, layer operations and more. Check it out!

Utilize the feature class created from CAD import to parsing out individual layers

2007-10-15T22:06:00.000-04:00

Last class, we imported a CAD polyline feature class of the campus to a single feature class in our campus geodatabase. We also georeferenced this new feature class to real-world coordinates using the Spatial Adjust toolbar.

This new feature class had many different features of the campus like buildings, sidewalks, utility poles and other important data. These features can delineated based on the 'layer' they were on in the CAD file. This information is brought over to the GIS in a field called 'layer'.

This class, we will use the georeferenced data that we imported from CAD to a single feature class to parse out into individual features classes.

HOW?
Utilize ArcCatalog to EXPORT layers. During the export using the query tool to select a subset of features to be exported to the new feature class. This will allow you to segregate features from individual CAD layer and export them to feature classes.

You should end up with individual feature classes in your geodatabase for buildings, sidewalks, utility poles, etc...

See graphic below for an example of how the dialog box should look for exporting the features from the buildings layer to a new Buildings feature class in the same geodatabase.

Starting the campus geodatabase

2007-10-02T13:38:00.000-04:00

This exercise will mark the beginning of our campus geodatabase project. Begin by creating a folder for this project. File management is vital to the success of all GIS projects. Make sure to maintain a logical and consistent file structure for this entire project.

OBJECTIVES:

Create a file based geodatabase
Incorporate ABTech main campus parcels into geodatabase
Create raster catalog of images for ABTech main campus

STEP-BY-STEP:

In ArcCatalog, create a file based geodatabase to store our project database.
Open ArcMap and load the parcels layer for the Buncombe County.
Utilize an attribute query to select the parcels owned by AB Tech. You'll need to be creative when selecting since all the parcels owned by AB Tech are not listed exactly the same attribute table.
Unselect any parcels that are not part of the main campus.
Export the selected parcels in to the geodatabase for this project. Name this new feature class something logical.
Go to the Buncombe County digital data download page and download the 2006 aerial grid. This will be used to determine which images you need for the campus.
http://www.buncombecounty.org/GOVERNING/depts/GIS/aerialImagery_06.htm - will take you to the download page.
Unzip the shapefile and add it to ArcMap.
Utitlize select by location (Selection drop down ==> Select by Location) and select the features in the grid that intersect the AB Tech parcels.
Export the selected polygons in the grid to the AB Tech geodatabase. Add the new grid layer for the ABTech campus to map document. Open the attribute table and determine the grid numbers for the AB Tech campus.
Go back to the Buncombe County digital data download page and download the images that go with the campus. Unzip them all into the same directory.
In ArcCatalog, right-click your geodatabase and create a new Raster Catalog. --Learn more about creating raster catalogs from the ESRI Support Center.
Type in a name for the new raster catalog.
Click the Spatial Reference Properties button to choose a coordinate system for the raster catalog. You should import the spatial reference from one of the images you downloaded.
Choose that you want your raster catalog to be unmanaged by the geodatabase (as opposed to managed).
Click OK.
Now you must get the images into your Raster Catalog. In ArcCatalog, drag and drop the images into the raster catalog.
Add the raster catalog to ArcMap.

Managing CAD data in ArcCatalog

Adding CAD data to ArcMap

Transforming CAD datasets

World Files

Database design and planning

2007-09-26T18:43:00.001-04:00

Common Geodatabase Tasks

File Geodatabase

An Overview of ArcSDE Geodatabase Administrations

Class 5 - more geodatabases

2007-09-04T22:59:00.000-04:00

INTRODUCTION

Today, we'll review the new geodatabase types available at 9.2 and continue with the ESRI Building Geodatabases tutorial.

LEARNING OBJECTIVES

Mostly a review from last class. We will be reviewing the different types of geodatabases available with ArcGIS 9.2 and the benefits of using geodatabases in your GIS work.

TERMS TO KNOW

File Geodatabse
Personal geodatabase
Scalable or ArcSDE geodatabase
Relational Database Management System (RDBMS)

CLASS DISCUSSION

Based around 2 podcasts from the ESRI Instructional Series Podcast

Types of Geodatabases at ArcGIS 9.2

An Overview of Geodatabases and Five Reasons Why You Should Use It

ACTIVE LEARNING EXERCISE

Begin ESRI Building Geodatabase tutorial (Exercises 4 - 6)