Transforming and Projecting Shapefiles in R & ArcGIS for Desktop?
Perhaps this is an issue with one of my original data sources, but I've searched extensively to address this problem both through ArcGIS and R.
I've got 2 separate sources of a county layer SourceA and SourceB.
I'm trying to project the SourceA layer so that it aligns with the SourceB layer.
The original SourceA layer is in NAD83, UTM zone 10 projection:
proj4string :[+proj=utm +zone=10 +datum=NAD83 +units=m +no_defs+ellps=GRS80+towgs84=0,0,0]
The SourceB layer is in NAD83, Albers, California.
proj4string : [+proj=aea +lat_1=34 +lat_2=40.5 +lat_0=0 +lon_0=-120 +x_0=0 +y_0=-4000000 +datum=NAD83 +units=m +no_defs+ellps=GRS80 +towgs84=0,0,0]
I've tried to transform the county data using both R and ArcGIS, but am having problems.
When I try to project it in ArcMap, the program puts in a string of characters (see circled image below: WGS84 to NAD 83 + WGS84 to NAD83) in the geographic transformation section, which it shouldn't because they're both supposedly in NAD83… (right?), and it won't let me take that string off the chart with that little X button. If I run it anyways, as setup in the screenshot below, it throws an error "invalid extent for output coordinate system".
When I use use spTransform in R to project the SourceA data to Albers California, it runs the transformation and results in a skewed county shape in comparison with the original SourceA shapefile (which is in UTM). I think this is to be expected (see screenshot below). But… that transformed layer won't align or even show up on the same map with the SourceB data that is also projected in NAD83, Albers California .
The SourceA layer after spTransform to Albers California reads the following proj4string:
proj4string :[+proj=aea +lat_1=34 +lat_2=40.5 +lat_0=0 +lon_0=-120 +x_0=0+y_0=-4000000 +datum=NAD83 +units=m +no_defs+ellps=GRS80 +towgs84=0,0,0]
Here's the R code using the spTransform command to transform the original SourceA data into NAD83 Albers, California resulting in the image above. Sourced from spatialreference.org:
county <- spTransform(county,CRS("+proj=aea +lat_1=34 +lat_2=40.5 +lat_0=0 +lon_0=-120 +x_0=0 +y_0=-4000000 +ellps=GRS80 +datum=NAD83 +units=m +no_defs"))
Three zipped shapefiles illustrating the problem can be downloaded off this dropbox link. 1) SourceA original projection, NAD83 UTM zone 10, 2) SourceA transformed to NAD83 Albers California through R's spTransform, and 3) SourceB in NAD83 Albers California.
Is there something wrong with the original SourceA or SourceB projection information? Any suggestions?
The problem is that the data was never in UTM to begin with, and so by having a UTM projection, the file was ultimately being told to be something it wasn't. (Such is life) :) Reprojecting it doesn't fix the problem, because the transformation math is based on coordinates that don't match the assigned projection.
To fix this I deleted the .prj file, and then changed the coordinate system of the dataframe to a few projections I thought might be close. Here in California we often use UTM or State Plane systems, and county governments often use the later. Modoc County is in State Plane Zone I. When I assigned the coordinate system State Plane Zone I Feet, the data (with the unassigned projection) snapped right into place, which is a good sign that that's its original projection. I then assigned the data the State Plane projection permanently. Now you can reproject it if you like and the math will be accurate.
To figure out which file has a problematic projection and get additional clues about how to fix it, you can plot the maps on an ArcGIS basemap. This will get the shapefiles to appear on the same screen so you can see which is problematic. In this case you can quickly see that the SourceA file is plotted off in the Atlantic Ocean far from it's proper location in California, while the SourceB file lines up appropriately.
A second clue to find out how to assign the proper projection comes by seeing that the SourceA object appears far larger than the correctly positioned SourceB file, which suggests that it is not projected in meters projection, but probably in US feet instead, hence why it looks ~3x too large. Some of the StatePlane projected coordinate systems use feet and this is often used by counties, so it is a good projection to try.
You can run the Define Projection tool in ArcMap to the NAD 1983 (2011) StatePlane California I FIPS 0401 (US Feet) and it will move it to the proper place with perfect alignment.
If this hadn't worked, several colleagues told me that it can be a painful process to try out all possible predefined projection systems. Furthermore, you can potentially still end up without a solution if the file is corrupted, under a custom defined projection system, or somehow completely distorted in its coordinate system.
I haven't been able to fix this in R yet.
Choosing an appropriate transformation
A geographic coordinate system defines a framework for identifying locations on a 3D globe. Each geographic coordinate system (GCS) has a spheroid which sets size and shape. Each geographic coordinate system is also tied to the earth in a particular way. Because of this, the same location on the ground will have different coordinate values in different geographic coordinate systems. Displaying data in a projected coordinate system can exaggerate the differences which can be from a few centimeters to hundreds of meters. If you are using datasets that are based on different geographic coordinate systems, you will need to set a geographic, or datum, transformation.
The terms geographic coordinate system and datum are often used interchangeably. Datum is an older term. The concept of a datum is included within a geographic coordinate system.
A geographic transformation is always defined in a particular direction, like from NAD 1927 to WGS 1984. Transformation names will reflect this: NAD_1927_To_WGS_1984_1. The name may also include a trailing number, as the above example has _1. This number represents the order in which the transformations were defined. A larger number does not necessarily mean a more accurate transformation. Even though a geographic transformation has a built-in directionality, all transformation methods are inversible. That is, a transformation can be used in either direction. ArcGIS will apply a transformation appropriately based on the input and output geographic coordinate systems.
If a pair of geographic coordinate systems does not have any transformations, it is sometimes possible to build a chain of transformations by using a third geographic coordinate system. Most often, WGS 1984 is the common link. The Create Custom Geographic Transformation tool can also be used to define a new transformation if you have the necessary information: method and parameter values.
Types of coordinate systems
There are two common types of coordinate systems used in GIS:
- A global or spherical coordinate system such as latitude–longitude. These are often referred to as geographic coordinate systems.
- A projected coordinate system based on a map projection such as transverse Mercator, Albers equal area, or Robinson, all of which (along with numerous other map projection models) provide various mechanisms to project maps of the earth's spherical surface onto a two-dimensional Cartesian coordinate plane. Projected coordinate systems are sometimes referred to as map projections.
Coordinate systems (either geographic or projected) provide a framework for defining real-world locations. In ArcGIS, the coordinate system is used as the method to automatically integrate the geographic locations from different datasets into a common coordinate framework for display and analysis.
Navigating in the data frame and working with its layers
The Tools toolbar is one of the primary ways that you interact with geographic information displayed in the data frame. It contains tools for working with the contents within the active data frame, for example, to pan and zoom your map, to identify features, and to measure distances.
Functions on the Tools toolbar
Allows you to zoom in to a geographic window by clicking a point or dragging a box.
Allows you to zoom out from a geographic window by clicking a point or dragging a box.
Allows you to pan the data frame.
Allows you to zoom to the full extent of your map.
Allows you to zoom in on the center of your data frame.
Allows you to zoom out on the center of your data frame.
Allows you to go back to the previous extent.
Allows you to go forward to the next extent.
Allows you to select features graphically, by clicking or dragging a box around them. You can also use the Select By Polygon, Lasso, Circle, and Line tools to select features using graphics drawn to the screen.
Unselects all the currently selected features in the active data frame.
Allows you to select, resize, and move text, graphics, and other objects placed on the map.
Identifies the geographic feature or place on which you click.
Triggers hyperlinks from features.
Triggers HTML pop-up windows from features.
Measures distances and areas on your map.
Finds features in the map.
Allows you to calculate point-to-point routes and driving directions.
Allows you to type an x,y location and navigate to it.
Opens a time slider window for working with time-aware layers and tables.
Allows you to create a new viewer window by dragging a rectangle.
In addition, right-clicking in the data frame displays a context menu of data navigation tools.
Right-clicking inside the data frame view displays this context menu.
Interactive panning and zooming using basemap layers
Smooth, continuous panning and zooming can be turned on and are productive, especially when using basemap layers.
Geographic Information Systems (GIS): On the web
Vanderbilt Campus Map - The Facilities Information Services Mapping Department is responsible for the creation and maintenance of the University's campus maps. Vanderbilt campus data is available to students, faculty, and staff at the University.
Metro Nashville Planning Department- Interactive Mapping Site - This public access service allows you to view property, zoning, topographic and planimetric data. In addition, it allows you to search the database by owner, address or parcel number.
Tennessee Spatial Data Server - distributes spatial data layers that are shared among Federal, State, and local GIS facilities in Tennessee.
Tennessee Map Portal - A portal for accessing a wide variety of GIS related information, resources, and on-line mapping services in Tennessee, indluding published map services for use in ArcGIS Desktop.
American Factfinder - Quick and interactive access to summary data, reports, and maps from the Census Bureau.
Census Tiger/Line Shapefiles - US Census Bureau access to free downloadable shapefiles including legal and statistical geographic areas, rivers, roads, etc.
ESRI Census Cartographic Boundaries - ESRI access to US Census Bureau free downloadable cartographic boundary shapefiles by geography type by county.
National Historic GIS -NHGIS provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States between 1790 and 2010.
ICPSR Historic Cartographic Boundaries - ICPSR (Inter-University Consortium for Political and Social Research) access to historic Census TIGER/line files, 1990 - 2006.
The National Map erver - US Geological Survey server providing free downloads of national base layers and elevation data as well as other geospatial data layers.
National Atlas of the United States (USGS) - Find and make maps that capture and depict the patterns, conditions, and trends of American life using data from a collection of Federal organizations.
ESRI World Basemap Data - Download ESRI Basemap data for use in GIS software. Features include country boundaries, cities, rivers, roads, etc. Select by area of interest.
ArcGIS Online- a cloud-based, collaborative content management system for maps, apps, data, and other geographic information. You can create maps on the web or add content from ArcGIS Online straight to your ArcGIS Desktop projects.
Other Data Link Sites
University of California, San Diego - A massive collection of GIS data sources sortable by topic, type, source, and region. The UCSD GIS Data libguide is an excellent starting point for your data search.
University of Tennessee - The UT Map Library GIS Data page provides a list of data links for Tennessee as well as the links to national and international data.
North Carolina State University - The NCSU Library GIS Data page provides an extensive list and descriptions of useful GIS data links.
Geographic Information Systems: Geospatial Guidance
Geospatial Analysis & File Conversion: Understanding basic possibilities of GIS
Data Cleaning & Management: Transforming and manipulating data for GIS analysis
Geospatial Visualization: Approaches to creating maps and illuminating GIS data
Geocoding: Generating latitude and longitude coordinates to reference data in GIS software
Georeferencing: Ascribing location data to scanned images of historic maps
The Structure of a Geographic CRS
A geographic CRS uses a grid that wraps around the entire globe. This means that each point on the globe is defined using the SAME coordinate system and the same units as defined within that particular geographic CRS. Geographic coordinate reference systems are best for global analysis however it is important to remember that distance is distorted using a geographic lat / long CRS .
The geographic WGS84 lat/long CRS has an origin - (0,0) - located at the intersection of the Equator (0° latitude) and Prime Meridian (0° longitude) on the globe.
Let’s remind ourselves what data projects in a geographic CRS look like.
Data Note: The distance between the 2 degrees of longitude at the equator (0°) is
69 miles. The distance between 2 degrees of longitude at 40°N (or S) is only 53 miles. This difference in actual distance relative to “distance” between the actual parallels and meridians demonstrates how distance calculations will be less accurate when using geographic CRS ’s
Want ArcGIS Pro to warn you when you’re using a transformation, like ArcMap does?
- Go to the Project tab > Options > Map and Scene > Spatial Reference and check the box for Warn if transformation between geographic coordinate system is required to align data sources correctly.
Don’t have enough transformations? Do you want more accurate transformations?
- Some transformations are grid-based, meaning they are very large files and not included in the standard installation of ArcGIS Pro. You can download them from My Esri. Select My Organizations. Next to either ArcGIS Pro or ArcGIS Desktop (ArcMap), click View Downloads. Scroll down to Data and Content and next to ArcGIS Coordinate Systems Data, click Download.
- Get more information at the Esri Community.
- You can also use the Create Custom Geographic Transformation tool. For an example of how to use this tool, see Adding a Newer Coordinate System Definition to an Older Version of ArcMap.
Know that a transformation exists, but it’s not showing up in the list?
- This may be because the extent of your data doesn’t overlap with the transformation’s area of use. Try adding some fake features to your data layer on the far side of the world. Run the Recalculate Feature Class Extent tool and see if the transformation becomes available.
- The extents of all transformations in ArcGIS can be found in Geographic and Vertical Transformation Tables.
Watch the Deep Dive into Transformations video to learn more and see some troubleshooting examples.
What GIS resources does Princeton have?
The University Library and the Office of Information Technology work together to provide GIS data, software, training, and project support to university faculty, staff and students.
GIS Data and Library services
A good analysis requires good data. An extensive collection of GIS data is available through the Map and Geospatial Information Center.
ArcGIS Desktop and ArcGIS Pro software are available to Princeton faculty, students and staff through a university-wide license, and can be downloaded onto PCs running Windows. Installation instructions for ArcGIS Pro 2.x are available. Please contact Bill Guthe at [email protected] for any installation questions.
ArcGIS Online/ Portal for ArcGIS are on-line mapping and analysis tools available to the Princeton community. These services are accessed through web browsers by going to the. Princeton University ArcGIS Online portal. Choose the Princeton University option to log in to the site using your Princeton NetID and password. Once on the site, you can create and load data, make web maps and build web applications. Please contact Bill Guthe at [email protected] or T. Wangyal Shawa at [email protected] if you have any questions.
Research Computing staff support ERDAS Imagine and other products from Hexagon Geospatial. ERDAS Imagine is used for image analysis, remote sensing, and GIS. A limited number of stand-alone licenses are available each year.
Harris Geospatial Solutions
ENVI is image analysis software built using IDL, a scientific programming language. A limited number of floating licenses are available each year.
Research Computing staff supports QGIS, an open-source GIS product that runs on most operating systems. The software can be downloaded from the QGIS site. Related open-source software such as PostgreSQL/PostGIS, GeoServer, OpenLayers, and Leaflet are also supported.
17554 Lec 004 &ndash Assistant Professor Sean Moran
Austin Community College &ndash Fall 2010
Tuesdays and Thursdays 8:45 AM to 11:20 AM at Northridge Campus (NRG), Building 3, Room 3231.
Sean Moran will be the instructor for Introduction to GIS.
Mr. Sean Moran is the Chair of the GIS Department and an Assistant Professor of GIS. He was formerly the Regional Planning Director at the Capital Area Planning Council (CAPCOG). He has over 15 years of professional planning, Geographic Information Systems (GIS), and Global Positioning Systems (GPS) experience. He has extensive experience utilizing information technology to facilitate planning, engineering, and environmental projects. His professional accomplishments include: developing the 2005 Vacant Land Inventory - a comprehensive inventory of vacant land in the Austin-Round Rock MSA coordinating and creating the digital Geologic Atlas of Texas securing key partnerships for the creation of the $40 million Texas Strategic Mapping Program and publishing GeoDisc 98: The 1998 Austin Metro GIS Inventory CD-ROM. Mr. Moran's experience as an educator, manager, coordinator, supervisor, and technician give him a comprehensive base of knowledge on which to draw. Prior to coming to ACC in 2009, Mr. Moran taught applied GIS to graduate-level planning students in the School of Architecture at the University of Texas. He has a BS in Forest Science from Texas A&M University and an MS in Community and Regional Planning from the University of Texas. Mr. Moran&rsquos contact information is listed below:
email [email protected]
T, Th 11:30 AM - 2:00 PM at NRG 3212 or by appointment
GIS (Geographic Information Systems) is a computer-based tool that uses spatial (geographic) data to analyze and solve real-world problems. This course is designed to introduce the student to the basic principles and techniques of GIS. The lab material will emphasize GIS data collection, entry, storage, analysis, and output using ArcGIS.
Ormsby, Tim et al. 2008. Getting to Know ArcGIS Desktop. Redlands, CA: ESRI Press. Second Edition, Updated for ArcGIS 9.3. ISBN 9781589482104. NOTE: You MUST use the edition that has been updated for ArcGIS 9.3.1. The software has changed significantly from version 9.2. Make sure the ArcGIS DVD in the book is version 9.3.
Readings assigned that are in in the required text will be available in electronic format. Most lectures include an assigned reading that should be completed before lecture. Students should come to lectures prepared to discuss the reading assignment.
An external USB flash or hard drive with at least 2GB of storage is required. A 4GB is even better. When it comes to GIS, the more storage space, the better.
Lecture will consist of an opening discussion, lecture, project exercise, and description of the lab assignment relative to the weekly topic. Students will be permitted to begin lab work if time permits.
Lab will begin with a guest speaker when appropriate otherwise the instructor will be available to assist students with the weekly lab assignment.
Introduction to GIS is designed to provide the students with an understanding of the methods and theories of spatial analysis that will allow students to apply GIS knowledge and skills to everyday life and their chosen careers, to apply the course towards an associate&rsquos degree at Austin Community College, and to prepare them for success in upper division courses in GIS at other institutions.
Students will learn how to compile, analyze, and present geospatial data while emphasizing the value of visual communication. Students will learn these basic geospatial concepts while working with ESRI&rsquos ArcGIS software.
By the end of this course, the student will be able to:
- Will be able to describe what geography and GIS are
- Will understand the importance of scale, projection, and coordinate systems in GIS
- Will understand vector and raster data structures and the appropriate use of each of these data structures
- Will understand the basics of data capture, storage, analysis, and output in a GIS and
- Will understand typical uses of GIS in business, government, and resource management.
Course Evaluation/Grading System
Grading components are based on the successful and timely completion of lab exercises and quizzes, three tests, and three projects.
The final grade is based on a total of 100 points and the following grade scale:
|A||90 &ndash 100|
|B||80 &ndash 89|
|C||70 &ndash 79|
|D||60 &ndash 69|
|F||0 &ndash 59|
Class participation is based on each student&rsquos contribution to class throughout the semester. While not a formal grading component, attending class and participating in lectures will influence your quiz, test, project, and final grades. I will take attendance in case there are any questions about your final grade and commitment to this course.
Each week&rsquos topic includes a textbook lab exercise(s) and supporting quiz. Quizzes will include 10 questions - 5 from the lecture and 5 from the lab. Quizzes will be accessed via the course Blackboard website and can be retaken as many times as desired. At the beginning of the semester, each student will receive a 20-point credit toward the quiz grading component. Students must complete all 15 quizzes with a score of 80% or better to retain all 20 points. Any quiz with a score of less than 80% at the end of the semester will result in a 2-point deduction from the quiz grading component. Successfully completing and studying the quizzes will improve your test scores.
There are two subject matter tests and one cumulative test that will be administered during class time. Each subject matter test will consist of 20 questions - 10 questions covering the lecture material and 10 questions covering the lab materials. The cumulative test will consist of 60 questions - 30 lecture questions and 30 lab questions. Each question is worth 0.5 points. Tests are structured to measure and reinforce overall comprehension.
There will be three projects assigned during the semester. Each project will include a work breakdown structure (i.e. list of tasks) and description of the final deliverable that builds on the material covered in lecture and lab. The first two projects will include a list of tasks supported by step-by-step instructions. The final project will include a list of tasks supported by more general instructions. I'll end each lecture with a demonstration of the corresponding project task. Students will be able to complete project tasks at the end of lecture and/or during lab. Each project is worth 10 points. Any project turned in late will be penalized 2 points per day. The projects are designed to build the skills and confidence required to complete real-world applications using GIS.
Please see the following course policies regarding attendance, withdrawals, incompletes, scholastic dishonesty, students with disabilities, and academic freedom.
While not a formal grading component, attending class and participating in lectures will influence your quiz, test, project, and final grades. I will take attendance in case there are any questions about your final grade and commitment to this course. You are responsible for any announcements made in class even if you were not in class that day. Students who miss lecture need to make arrangements to hand in assignments and obtain class related notes, handouts, and announcements.
The last day to withdraw from this course for the Fall 2010 session is Thursday, November 18, 2010. It is the student&rsquos responsibility to withdraw from the course. If you have attended at least one class, the instructor will NOT withdraw you from the class. The instructor will only withdraw those students who have never attended class.
An Incomplete grade, or &ldquoI&rdquo, is rarely assigned in this course. In the event that a true emergency (e.g. such as hospitalization) prevents the student from taking the last test, a grade of &ldquoI&rdquo may be given at the discretion of the instructor. Incompletes must be made up by the published date in the ACC College Calendar, or the &ldquoI&rdquo will automatically be converted to an &ldquoF&rdquo.
Acts prohibited by the college for which discipline may be administered include scholastic dishonesty, including but not limited to cheating on an exam or quiz, plagiarizing, and unauthorized collaboration with another in preparing outside work. Academic work submitted by students shall be the result of their thought, research, or self-expression. Academic work is defined as, but not limited to tests, quizzes, whether taken electronically or on paper projects, either individual or group classroom presentations, and homework.
Students with Disabilities
Each ACC campus offers support services for students with documented physical or psychological disabilities. Students with disabilities must request reasonable accommodations through the Office for Students with Disabilities on the campus where they expect to take the majority of their classes. Students are encouraged to do this three weeks before the start of the semester.
Each student is strongly encouraged to participate in class discussions. In any classroom situation that includes discussion and critical thinking, there are bound to be many differing viewpoints. Students may not only disagree with each other at times, but the students and instructor may also find that they have disparate views on sensitive and volatile topics. It is my hope that these differences will enhance class discussion and create an atmosphere where students and instructor alike will be encouraged to think and learn. Therefore, be assured that your grades will not be adversely affected by any beliefs or ideas expressed in class or in assignments. Rather, we will all respect the views of others when expressed in classroom discussions.
|Week 1 - Introduction to GIS|
|L ecture 8/24 and Lab 8/26|
GIS professionals rely on maps to illustrate relationships that are difficult to explain in words. Cartography, the art of making a map, is a valuable skill utilized by variety of professions to clarify relationships and increase understanding. A good map can succeed where words fail.
Not long ago, cartographers relied on pencils and paper to make maps. Today, we use Geographic Information Systems (GIS) to make maps. There are many GIS software packages available to GIS professionals, including: ArcGIS, Google Earth, MapInfo, AutoCAD Map, GeoMedia, Intergraph MGE, Smallworld, and GRASS. Of these, ArcGIS is the most established GIS software.
Students will be introduced to GIS, the ACC GIS Program, the GIS profession, and GIS Software.
- Review Syllabus, Course Rationale, and Objectives
- Introduce GIS
- Become familiar with ArcGIS software
- Become familiar with ArcMap menus, toolbars, and map elements and
- Learn how to explore data using ArcMap and ArcCatalog.
Getting to Know (GTK) ArcGIS Desktop. Chapter 1 Introducing GIS
GTK ArcGIS Desktop . Chapter 2 Introducing Ar cGIS Desktop
GTK ArcGIS Desktop. Chapter 3 Exploring ArcMap
GTK ArcGIS Desktop. Chapter 4 Exploring ArcCatalog
GTK ArcGIS Desktop. Exercise 3a Displaying Map Data
GTK ArcGIS Desktop. Exercise 3b Navigating a Map
GTK ArcGIS Desktop. Exercise 3c Looking at Feature Attributes
GTK ArcGIS Desktop. Exercise 4a Browsing Map Data
GTK ArcGIS Desktop. Exercise 4b Searching for Map Data
GTK ArcGIS Desktop. Exercise 4c Adding data to ArcMap
|Week 2 - Envisioning Information|
|L ecture 8/31 and Lab 9/2|
According to Ed Tufte, &ldquoenvisioning information is to work at the intersection of image, word, number, art.&rdquo Geographic Information Systems (GIS) enables us to understand this intersection and then present our findings in a compelling format. My course goal is to teach students the fundamentals skills required to acquire, analyze, and envision geospatial information.
Students will be introduced to Ed Tufte, the principles of envisioning information, and how they apply to maps.
- Introduce the concept of envisioning information
- Understand the value of maps
- Learn how to symbolize features and rasters in ArcGIS and
- Learn how to classify features and rasters in ArcGIS.
GTK ArcGIS Desktop. Chapter 5 Symbolizing Features and Rasters
GTK ArcGIS Desktop. Chapter 6 Classifying Features and Rasters
Freymann-Weyr, Jeffrey. National Public Radio, Weekend Edition - Edward Tufte, Offering &lsquoBeautiful Evidence&rsquo. August 20, 2006.
Krygier, John. Making Maps: DIY Cartography &ndash How Useful is Tufte for Making Maps? . August 16, 2007.
GTK ArcGIS Desktop. Exercise 5a Changing Symbology
GTK ArcGIS Desktop. Exercise 5b Symbolizing Features by Categorical Attributes
GTK ArcGIS Desktop. Exercise 5c Using Styles and Creating Layer Files
GTK ArcGIS Desktop. Exercise 5d Symbolizing Rasters
GTK ArcGIS Desktop. Exercise 6a Classifying features by Standard Methods
GTK ArcGIS Desktop. Exercise 6b Classifying features manually
GTK ArcGIS Desktop. Exercise 6c Mapping density
GTK ArcGIS Desktop. Exercise 6d Using interactive labels and creating annotation
|Week 3 - Features and Attributes|
|L ecture 9/7 and Lab 9/9|
The "G" in GIS refers to geospatial features such as lakes, soils, and buildings that are represented in a GIS. The &ldquoI&rdquo refers to the information, or attribute data, associated with each geospatial feature. The "S" refers to the system, or software, that stores, manages, displays, analyzes, and publishes features and associated attributes. Features and attributes are the basic building blocks of a GIS.
In addition to learning about features and attributes, students will also watch The World in a Box video on state-of-the-art GIS installations and the people who use them.
- Understand what features are and how they model (i.e. represent) geospatial features
- Understand what attributes are and how the describe geospatial features and
- Explore how features and attributes are linked and displayed in a GIS.
GTK ArcGIS Desktop. Chapter 7 Labeling Features
GTK ArcGIS Desktop. Exercise 7a Using Dynamic Labeling
GTK ArcGIS Desktop. Exercise 7 b Setting Rules for Placing Labels
GTK ArcGIS Desktop. Exercise 7 c Using Interactive Labels and Creating Annotation
|Week 4 - Attribute Queries|
|L ecture 9/14 and Lab 9/16|
The true power of a GIS is accessed via queries and analysis. Attribute queries are standardized descriptions for retrieving data from a GIS or Relational Data Management System (RDBMS). For example, the query "SELECT Parcels WHERE Acre > 1" might be described in lay terms as select all parcels that are greater than 1 acre. Understanding how to execute standard attribute queries is an important skill for GIS professionals to master.
- Use ArcGIS to find and query attributes
- Introduce selection methodologies available in ArcGIS
- Use Structured Query Language (SQL) to execute standard database queries and
- Create summary reports based on attribute queries.
GTK ArcGIS Desktop. Chapter 8 Querying Data
ArcGIS Desktop 9.3 Help &ndash Using Select by Attributes. April 24, 2009.
ArcGIS Desktop 9.3 Help &ndash SQL Reference. April 24, 2009.
GTK ArcGIS Desktop. Exercise 8a Identifying, Selecting, Finding, and Hyperlinking Features
GTK ArcGIS Desktop. Exercise 8b Selecting Features by Attribute
GTK ArcGIS Desktop. Exercise 8c Creating Reports
|Week 5 - Tables|
|L ecture 9/21 and Lab 9/23|
Each feature's attributes are stored as a record in a table. A table is a mode of visual communication and a means of arranging data in rows and columns. Each row represents a record and each column represents a field, or attribute type. In addition to attributes, GIS tables can also store the geometry for each feature as well. The true value of a GIS is its ability to store a large number of features and associated attributes in tables - only selecting and displaying the data required for a specific analysis.
Students will be introduced to the basic structure, type, and format for tables stored and accessed in a GIS.
- Identify basic structure and data types for tables stored in a GIS
- Identify common tabular formats imported into a GIS and
- Learn how to perform a join and relate between two tables and a feature class and a table.
GTK ArcGIS Desktop. Chapter 9 Joining and Relating Tables
ArcGIS Desktop 9.3 Help &ndash An Overview of Tables and Attribute Information. April 24, 2009.
ArcGIS Desktop 9.3 Help &ndash About Tabular Data Sources. April 24, 2009.
ArcGIS Desktop 9.3 Help &ndash Joining Tables. April 24, 2009.
ArcGIS Desktop 9.3 Help &ndash Relating Tables. April 24, 2009.
ArcGIS Desktop 9.3 Help &ndash Joining the Attributes of Features by Location. April 24, 2009.
GTK ArcGIS Desktop. Exercise 9a Joining Tables
GTK ArcGIS Desktop. Exercise 9b Relating Tables
|Week 6 - Spatial Queries|
|L ecture 9/28 and Lab 9/30|
While tables and attribute queries are associated with a number of software packages (e.g. spreadsheets, database management software, financial accounting software, etc.), geospatial data and queries are unique to GIS. Spatial queries allow users to select features from existing data based on their proximity to each other. For example:
- Which businesses are within 1000-feet of a new school?
- How many wells are registered within an aquifer?
- Which roads are crossed by a proposed rail line?
These are all spatial queries that can be answered using a GIS. Students will be introduced to spatial queries and how to execute them using GIS.
- Understand spatial relationships and how to query them in GIS
- Understand how, when, and why to use definition queries
- Learn how to perform a multi-step spatial query and
- Learn how to join attributes by location.
GTK ArcGIS Desktop. Chapter 10 Selecting Features By Location
GTK ArcGIS Desktop. Exercise 10a Using Location Queries
GTK ArcGIS Desktop. Exercise 10b Combining Attribute and Location Queries
|Week 7 - Geoprocessing|
|L ecture 10/5 (First Test Taken at Beginning of Lecture) and Lab 10/7 (First Project Due at End of Lab)|
Geoprocessing refers to the development of new data by applying a spatial operation to existing data. It is one of the core functions of a GIS and can prove an invaluable asset to the GIS professional. Examples of applications that rely on geoprocessing vector data include:
- Consolidating contiguous habitat zones
- Creating new market service areas based on ZIP code boundaries and
- Performing a suitability analysis for a specific project area
Some of the more common geoprocessing functions using vector data are merge, dissolve, and clip.
GTK ArcGIS Desktop. Chapter 11 Preparing Data for Analysis
ArcGIS Desktop 9.3 Help &ndash Geoprocessing. December 9, 2008.
GTK ArcGIS Desktop. Exercise 11a Dissolving Features
GTK ArcGIS Desktop. Exercise 11b Creating Graphs
GTK ArcGIS Desktop. Exercise 11c Clipping Layers
GTK ArcGIS Desktop. Exercise 11d Exporting Data
|Week 8 - Spatial Analysis|
|L ecture 10/12 and Lab 10/14|
In addition to making maps and storing information, GIS is a powerful analysis tool that can perform a number of spatial analyses. Discreet features are best represented and analyzed as vector datasets. For example, determining whether any septic tanks are within 500 feet of a proposed well. Continuous features are best represented and analyzed as raster datasets. For example, where are the steepest slopes along a proposed high-speed rail corridor. Your objective will ultimately determine how you store and analyze your data.
Students will be introduced to the various spatial analysis performed in a GIS.
- Introduce vector, raster, and three dimensional spatial analysis
- Understand the application of spatial analysis and
- Perform spatial analyses using vector and tabular data.
GTK ArcGIS Desktop. Chapter 12 Analyzing Spatial Data
ArcGIS 9.3 Help. An Introduction to the Fundamental Tools. December 9, 2008
GTK ArcGIS Desktop. Exercise 12a Buffering Features
GTK ArcGIS Desktop. Exercise 12b Overlaying Data
GTK ArcGIS Desktop. Exercise 12c Calculating Attribute Values
|Week 9 - Map Projections and Scale|
|L ecture 10/19 and Lab 10/21|
We use two dimensional maps to represent a three dimensional surface because the Earth is too large, complex, and awkward to carry in our back pocket. The process of transforming and shrinking a spherical earth to a flat map is called projection and scale. While creating a more practical medium, map projections and scale also introduce error. Understanding the types of error introduced by map projection and scale and how they impact your analysis is essential to GIS.
- Introduce map projections, coordinate systems, and scale and
- Understand how to identify the appropriate map projections, coordinate systems, and scale for your GIS application.
GTK ArcGIS Desktop. Chapter 13 Projecting Data in ArcMap
ArcGIS Desktop 9.3 Help &ndash Getting Started with Map Projections. February 12 , 2009.
GTK ArcGIS Desktop. Exercise 13a Projecing Data on the Fly
GTK ArcGIS Desktop. Exercise 13b Defining a Projection
|Week 10 - Data Types, Structures, and Formats|
|L ecture 10/26 and Lab 10/28|
Maps use basic shapes, or data types (e.g. points, lines, polygons, grids, and triangles), to represent complex geospatial data. In addition to shapes, a GIS utilizes tabular data to store information about individual shapes. These data types are the fundamental building blocks on which a GIS is based. Understanding the different data types and their structure will ensure you select the most appropriate type to represent your data.
Additionally, geographic features can be represented as more than just points, lines, and polygons. Now they can accurately model the rules and relationships associated with the natural and physical world. For example:
- A river can be modeled to only flow downstream,
- A road could be modeled to hold a maximum level of traffic, and
- A house can be modeled to never exist within the 100-year floodplain.
Vector data stored in a geodatabase can utilize relationships, domains, validation rules, and topology to more accurately model the geography they represent.
These different data types can be stored in a variety of competing formats, including: hard copy, AutoCAD (*.dwg), MapInfo (*.tab), ESRI Personal Geodatabase (*.mdb), ESRI File Geodatabase, MrSID (*.sid), dBase IV (*.dbf), etc. We will explore these various formats and discuss the merits of each.
- Recognize the different data types and structure available to represent geospatial and tabular data
- Learn how to select the most appropriate data type and structure to support your objective
- Discuss the value of smart feature in planning applications
- Understand the role of subtypes, relationships, domains, validation rules, and topology
- Recognize the most common GIS data formats
- Explore different data types, structures, and formats using ArcGIS and
- Learn how to develop a geospatial inventory.
GTK ArcGIS Desktop. Chapter 14 Building Geodatabases
GTK ArcGIS Desktop. Chapter 15 Creating Features
GTK ArcGIS Desktop. Exercise 14a Creating a Personal Geodatabase
GTK ArcGIS Desktop. Exercise 14b Creating Feature Classes
GTK ArcGIS Desktop. Exercise 14c Adding Fields and Domains
GTK ArcGIS Desktop. Exercise 15a Drawing Features
GTK ArcGIS Desktop. Exercise 15b Using Feature Construction Tools
|Week 11 - Data Creation, Collection, and Quality|
|L ecture 11/2 and Lab 11/4|
Good decisions are based on good data. GIS professionals should know where to find reliable geospatial data that can be quickly analyzes and presented. Understanding what geospatial and attribute data is required to support your objectives and mission will ensure your GIS stays focused on the task at hand.
If your data does not already exist, you will need to create it. Because creating data is often the most expensive part of your project, understanding what data you need and how to create it is vital. In addition to data creation, we will discuss the merits of utilizing a pilot project and backing up your data.
Understanding errors and how to mitigate them will improve your GIS project. Quality assurance (QA) refers to a system of process controls that ensure a quality product. QA often involves an audit trail that can be used to measure progress and improve product quality. Quality control (QC) refers to individual process controls that involve product testing, review, and validation. Understanding the various sources of error and how to mitigate them will instill confidence in your data and analysis.
- Be able to identify the geospatial data required to support a process
- Understand the differences between utilizing existing data and creating your own
- Learn where to find data
- Understand when you need to create data
- Recognize when it is appropriate to use a pilot project
- Learn how to create vector data
- Learn how to create attribute data
- Back up your data early and often
- Understand the relationship between error, accuracy, and precision
- Discuss opportunities to introduce error and how to mitigate them
- Be able to distinguish between quality control and quality assurance
- Learn how to establish and audit trail and
- Discuss the importance of good data management.
GTK ArcGIS Desktop. Chapter 16 Editing Features and Attributes
ArcGIS Desktop 9.3 Help &ndash About Creating New Features. May 21, 2009.
Foote, Kenneth E. and Margaret Lynch. The University of Colorado &ndash The Geographers Craft &ndash Data Sources for GIS. 1995.
Foote, Kenneth E. and Donald J. Huebner. The University of Colorado &ndash The Geographers Craft &ndash Error, Accuracy, and Precision. 1995.
Foote, Kenneth E. and Donald J. Huebner. The University of Colorado &ndash The Geographers Craft &ndash Managing Error. 1996.
Wikipedia contributors. Quality assurance [Internet]. Wikipedia, The Free Encyclopedia 2009 Jan 12, 15:41 UTC [cited 2009 Jan 15].
Wikipedia contributors. Quality control [Internet]. Wikipedia, The Free Encyclopedia 2009 Jan 7, 16:42 UTC [cited 2009 Jan 15].
GTK ArcGIS Desktop. Exercise 16a Deleting and Modifying Features
GTK ArcGIS Desktop. Exercise 16b Splitting and Merging Features
GTK ArcGIS Desktop. Exercise 16c Editing Feature Attribute Values
|Week 12 - Geocoding|
|L ecture 11/9 and Lab 11/11|
Ask someone what their address is and they're likely to respond with their address. Ask them what their coordinates are and they're likely to give you a blank stare. Geocoding is the process of converting a descriptive location, such as an address, to a pair of geographic coordinates that can be viewed and analyzed in GIS.
Students will be introduced to geocoding and will perform a geocoding exercise.
- Understand geocoding and its application
- Create an address locator
- Geocode addresses from a table
- Find individual addresses
- Standardize address and reference data
- Interpret geocoding results and
- Rematch addresses automatically and interactively.
GTK ArcGIS Desktop. Chapter 17 Geocoding Addresses
ArcGIS 9.3 Help. Understanding Geocoding, June 11, 2010.
GTK ArcGIS Desktop. Exercise 17a Creating an Address Locator
GTK ArcGIS Desktop. Exercise 17b Matching Addresses
GTK ArcGIS Desktop. Exercise 17c Rematching Addresses
|Week 13 - Cartography|
|L ecture 11/16 (Second Test Taken at Beginning of Lecture) and Lab 11/18 (Second Project Due at End of Lab)|
Cartography is the study and practice of making maps. It combines science, aesthetics, and technique to communicate spatial information. Cartographers use a series of standard map elements arranged along a visual hierarchy to convey spatial information and analysis. A good map can succeed where words fail.
Students will be introduced to standard map elements, their purpose, and how to arrange them along a visual hierarchy.
- Understand the value of maps
- Understand basic cartographic techniques and why they are important
- Become familiar with map elements and the visual hierarchy and
- Generate a cartographic product using ArcGIS.
GTK ArcGIS Desktop. Chapter 18 Making Maps from Templates
GTK ArcGIS Desktop. Chapter 19 Making Maps for Presentation
Wikipedia contributors. Cartography. Wikipedia, The Free Encyclopedia. January 15, 2010, 14:54 UTC. Accessed August 19, 2010.
Foote, Kenneth E. and Shannon Crum. The University of Colorado &ndash The Geographers Craft &ndash Cartographic Communication. 1995.
GTK ArcGIS Desktop. Exercise 18a Opening a Map Template
GTK ArcGIS Desktop. Exercise 18b Adding X,Y Data to a Map
GTK ArcGIS Desktop. Exercise 18c Drawing Graphics on a Map
GTK ArcGIS Desktop. Exercise 19a Laying Out the Page
GTK ArcGIS Desktop. Exercise 19b Adding a File
GTK ArcGIS Desktop. Exercise 19c Adding a North Arrow, Scale Bar, and Legend
GTK ArcGIS Desktop. Exercise 19d Adding Final Touches and Setting Print Options
|Week 14 - Presentation Mediums|
|L ecture 11/23 and no Lab (Thanksgiving Holiday)|
Once you&rsquove acquired and analyzed your data, the final step is to envision it. Selecting your presentation medium will depend on your audience, budget, and timeline. Static hard copy and digital maps, reports, live presentations, posters and pamphlets, and interactive web sites are the primary presentation mediums GIS professionals use to present their findings.
- Recognize the importance of visual communication
- Discuss the different types of presentation medium and their appropriate use and
- Learn how to generate different presentation medium.
None (Thanksgiving Holiday)
|Week 15 - Models, Metadata, and Mapping Law|
|L ecture 11/30 and Lab 12/2|
Models, metadata, and mapping law are all distinctly different, but important aspects of GIS. Models are automated scripts visualized as flowcharts that perform complex GIS operations. Constructed in ArcGIS ModelBuilder, models are a great way to perform multiple "what if" scenarios.
Metadata, or information about data, provides a common set of terminology, definitions, and information about your GIS data. Metadata is essential when assimilated data from multiple sources, time periods, and/or scales. There are a number of standardized metadata templates and software available to GIS professionals.
Mapping law refers to a number of legal issues all GIS professionals should consider, including: data access, privacy issues, liability, and copyright.
- Introduce and build a simple model in ArcGIS ModelBuilder
- Introduce metadata and metadata standards
- Learn how to use the Metadata tool in ArcCatalog and
- Discuss various GIS legal issues.
GTK ArcGIS Desktop. Chapter 20 Creating Models
ArcGIS 9.3 Help. About Metadata, June 15, 2010.
GTK ArcGIS Desktop. Exercise 20a Starting a Model
GTK ArcGIS Desktop. Exercise 20b Building a Model
GTK ArcGIS Desktop. Exercise 20c Enhancing a Model
|Week 16 - Final Test and Project|
|L ecture 12/7 and Lab 12/9 ( Final Test Taken at Beginning of Lab and Final Project Due at End of Lab)|
Students will be able to work on the their final project during lecture. Students will take the final test at the beginning of lab on December 9th and should submit the final project deliverables to the instructor via Blackboard prior to the end of lab on December 9th. Class projects turned in late will be penalized 2 points per day.