EXERCISE 5 – Hurricanes, The White House, and Nail Salons

EXERCISE 5 – Hurricanes, The White House, and Nail Salons

Environmental Resources 372:362
Intermediate Environmental Geomatics

Geocoding 101

Today we are going to make some spatial data from scratch.

After today you should be able to:

Create a table containing x,y coordinates

Convert it into a set of points (shapefile)

Address match a table

Edit and print metadata.

From 1600 Pennsylvania Avenue to Lat: 38.8971443 Lon: -77.0368347

We all understand street addresses better than decimal degrees, so why can't we just get our computers to think that way? Well, to some degree (pun intended), we can. If you have appropriate software (like ArcGIS), and appropriate reference data (like TIGER street files from the U.S. Census Bureau) you assign coordinates to a record based upon its street address. This act of assigning coordinates to street addresses is commonly called address geocoding.

Address geocoding is especially popular in marketing, parcel delivery, and other geo-business applications because it allows for easier geographic analysis of mailing lists, customer lists, and competitors. It is also part of popular web-based applications like Google maps that ask for an address to help you make a map. Almost all of these begin with some version of the TIGER (Topologically Integrated Geographic Encoding and Referencing) street files, but have cleaned these up and added information. On a nationwide basis the clean up can be expensive. That's one reason why free services (like Google) might be off a little on addresses like 1600 Pennsylvania Ave or 14 College Farm Rd, but expensive pay services can get it really close.

Hurricane Tracking

The good folks at NOAA have helped track plenty of hurricanes over the years. To get to the top level of the hurricane archives, follow this link:

http://www.nhc.noaa.gov/pastall.shtml

Choose a year, then a hurricane. Try to use one from 2005, 2006 or 2007. Open the Word document for your hurricane and scroll down to the table that includes the latitude and longitude information. Many, but not all, have Lat Long coordinates in a table. The more recent ones will have better data, but the older ones may have more exciting paths to follow.

Simply highlight the entire table and copy it, then paste it into a blank Excel spreadsheet. (You might need to use Paste Special...and paste it as Unicode text)

You need to clean this table up a little. Get rid of the merged cells and empty rows, convert your "wests" to negatives (using a formula something like this: =C3*(-1)), turn the topmost row into field names (something useful and simple - use only letters). If you are keeping the Stage column, be sure all the cells are populated with the correct data. Check out \\ad-rsc\data\teach\intgeo\ClassWork\fran.xls for a idea of what a “clean” file looks like. Make sure all the entries in the data column are consistent as well. Save it as an Excel file. You might need to close the file in Excel before you can do anything with it in Arc9.

Start a New Map. ArcGIS 9.2 allows us add Excel files directly to ArcMap, but there’s a bug (feature?) that requires there to be some other type of data in the data frame before adding the Excel file. So add \\ad-rsc\data\teach\intgeo\ClassWork\avdata\world\cntry04 and latlong. Then Add Sheet1 of the Excel file to ArcMap. Open the table to make sure it looks ok. Right click on the table in the Table of Contents and choose to Display the XY data. Make sure it is guessing your X and your Y correctly (then accept the defaults and say OK).

When you have plotted the points, add the Lat/Long and Countries layers for context. Export your hurricane data as a shapefile so that it is saved in a more useful format.

It's Metadata Time!

Now that you've created your own hurricane shapefile, take a shot at entering some basic metadata for it. Fire up ArcCatalog, find your hurricane shapefile and view its metadata. Thankfully, ArcCatalog has gone through the trouble of automatically entering some of the metadata, such as the Spatial Domain and Attribute Information. Notice that by choosing a different style sheet in the Stylesheet drop down menu, you can change the way the metadata is organized and displayed but the metadata itself doesn't change.

Click on the Edit Metadata button next to the Stylesheet drop down menu. Notice there are two levels of tabs for navigating through the metadata. Explore the tabs to see how you'd go about accessing the different types of metadata for editing. Fill out the Description boxes and the Data Set Credit under the Identification->General Tab, and the Identification->Time Period, Status and Keywords (don't worry about the thesaurus or stratum fields) information. Remember, you created the shapefile but not the data, so be sure to give credit where credit is due. The federal standards for metadata can be found at http://www.fgdc.gov/metadata/metadata.html. For a taste of well-done metadata, look at the examples found at http://njgeodata.state.nj.us/. To access the data and metadata at this site, you need to create a login, but it's worth the effort because they have a lot of data that you might find useful in a few weeks.

The Match Game

A different way to create data from scratch is to use a geocoding system based on street addresses.

Go to an online Yellow Pages type directory and find at least ten street addresses in Middlesex County (maybe something like, 10 tire stores, or ten public libraries, or ten bookstores, or ten churches, or ten wellness centers, etc.). Open a new Excel file and enter these addresses with the street address, town, zip code, and the name of the facility or store as your fields. The first row in the Excel file must be the names of your fields, not actual data. Use Address, City, Zip, and Name as your first row field names. Save this as an Excel file. Take a look at \\ad-rsc\data\teach\intgeo\ClassWork\ad.xls to see what it should look like.

Open a new map document in ArcMap. Add the street layer from \\ad-rsc\data\teach\intgeo\ClassWork\middlese. Now add Sheet1 from the Excel file you created containing address.

Open it and see that it all made it alright, then close it. Right click on this table in the Table of Contents and choose to Geocode Addresses. Add the address locator from \\ad-rsc\data\teach\intgeo\ClassWork\middlese that is called street.mxc. Make sure that you Zone is your zip code.

And set your geocoding options to include ALL 4 possible Output Fields. Hit OK.

If you have less than 75% matching, you should use the Interactive matching to see if you can improve your odds. We'll go over this one in class for sure.

What is the coordinate system for these data points?

Assignment 5- Due Monday March 3rd

You should turn in 2 maps. One of your hurricane, one of your address matching. Make 'em nice. Also turn in your edited hurricane metadata.

Additional Notes on Excel

If the Excel file isn’t working, try saving it as a CSV – a comma delimited text file. If neither can be loaded into ArcMap, try quitting Excel and then adding one of them.