Mapping Center

Tree symbols are a great way to enhance the appearance of a large scale, detailed map. To make attractive point symbols for trees, you need a good place to start from and thankfully all of us ArcGIS users have that. Using multi-layer character marker symbols, the variety of tree symbols you can create is endless. This blog is meant to introduce (or reintroduce) you to the ESRI US Forestry 2 font. It is also meant to give you some tips for creating a variety of tree symbols to use on your maps.

The most important part of the process to understand is the Symbol Property Editor and the capabilities/functionalities that are available to you in this dialog. If you aren’t familiar with the Symbol Property Editor dialog, a good starting point to learn more about it is a previous Mapping Center blog post: Customizing Multi-Layer Symbols.

With the Symbol Property Editor, you can create multi-layer symbols, which are symbols that are composed of multiple layers of graphics within one symbol. In the examples above, you can see how the layers can be combined to create an unlimited number of tree symbols.

Using a multi-layer symbol is an effective way to give the impression of "leafiness" to your tree symbols. Incorporating multiple colors, angle rotations, or other characteristics, such as fruits or flowers, make your tree symbols appear truer to reality.

To create your tree symbols, you’ll work with character marker symbols that use the ESRI US Forestry 2 font (Figure 1).

Figure 1. The ESRI US Forestry 2 font.

To access this font, first set your symbol type to Character Marker Symbol in the Type dropdown of the Symbol Property Editor. Then, in the Font dropdown, scroll to ESRI US Forestry 2 (Figure 2).

Figure 2. The Symbol Property Editor is used to create Character Marker Symbols.

In this font you will find the individual components needed to create a variety of tree symbols.

To create the tree symbol in Figure 3, three layers are used. Each layer within the symbol has its own properties. The first and third layers of the symbol both use the same character marker (Unicode 189), while the second layer’s character marker symbol is Unicode 187. Each layer is a different color; the first layer is a lighter shade of green than the third layer which helps promote the effect of leaves on the same tree with different levels of illumination. The second layer is brown and put in between the first and third layers so it looks as though there are branches in the tree. The second and third layers have an angle of 65 assigned to them with an X Offset of 2 points so they are visible underneath the first layer. Finally, the second layer is approximately 5 points smaller than the first and third layers to give the impression of leaves coming from the branches.

Figure 3. The tree Character Marker Symbols are created as multi-layer symbols.

You can use the sample trees style (.zip file, 0.17MB) associated with this blog post to begin exploring how you can create tree symbols in ArcGIS using the ESRI US Forestry 2 font. Look through the sample symbols and the other character markers in the font, play around with them, and most importantly, have fun!

September and October sure went fast. We on the Mapping Center team have been very busy working on mapping projects, and have not spent as much time here--but we're finding a balance and will be getting more good blogs done soon (several are in the pipeline).

This post's topic is important because many of the questions we get on Ask a Cartographer are about where to get map data. I think a big reason for this is because most ESRI's software users work in larger organizations and thus, don't get much in the way of a hands-on experience with ESRI, so they often do not know about all of what they get with their ArcGIS license.  ESRI's online presence (blogs, resource centers, and ArcGISOnline) are all important ways to connect the day to day users of ArcGIS software to valuable content. 

Some of that content is map data--and ESRI has worked hard to provide progressively better and better map data, free, to licensed users of our software*.  As of a few years ago, the quality of that data was arguably as good as any data out there--and our data continues to improve. Today, for many of our datasets, I don't know of a better source.

Now there is a new blog, the ArcGIS Data Blog, that you should subscribe to in order to keep up on what's new with all that data--this will give you an advantage by being able to produce better maps because you've got better content to use.

* Not all that data may be redistributed or used in for profit commercial uses--so check the help and metadata: here is a help topic that gives an overview of the data and it contains links and information about what your license permits.

Need to add a quick locator map to your page layout? Want to spice things up a bit? Try this locator map – it has visual appeal because of the 3D appearance (promoted by the choice of projection and the gradient fill). There are just a few basic steps to creating this map: 1) Prepare the data to make the map, 2) create the map, 3) add your area of interest (optional), and 4) export the data used to make the map, if desired (this will save some drawing time for you.)

Note that this is a technique you would want to use only if your area of interest is large enough to be seen on the map, and it is best used when you want the map reader to get an idea of where in the world your area of interest is located.

Prepare the data

1. Get these data from ESRI Data and Maps CD: World30 (this is the graticule for the world in 30 degree increments and the path to the data is \dm_stmap_dvd\world\data\world30.sdc\world30), Country (this is a generalized country polygon feature class and the path to the data is \dm_stmap_dvd\world\data\country.sdc\country).
2. Dissolve World30 using the Dissolve tool (this is in the Data Management Tools toolbox, and it is located in the Generalization toolset). Use the Dissolve tool to create a feature class that has the extent of the world but no graticule lines. Call it World30_dissolved. This will be the polygon feature class that you will symbolize with a gradient fill.
3. Create the color ramp that you will use to symbolize the ocean (this is actually the World30_dissolved feature class that you created in the previous step). This should be created as a multi-part algorithmic color ramp with two parts:
   • Top part Color 1 - HSV 195, 64, 95; Top part Color 2 - HSV 195, 38, 95.
   • Bottom part Color 1 - HSV 195, 38, 95; Bottom part Color 2 – White (HSV 0, 0, 100).

   To create a new color ramp, from the top menu bar, click Tools > Styles > Style Manager. On the left hand side of the dialog, expand your personal style (or the style in which you want to create this color ramp) and highlight the Color Ramps folder. On the right hand side of the dialog, right click anywhere in the white space and click New > Multi-part Color Ramp. In the Multi-part Color Ramp Properties dialog, click Add and click Algorithmic Color Ramp. Click Add again to add one more algorithmic color ramp. Highlight each color ramp and click Properties to assign the color values listed above.

   

   Create the map

4. Add all the data to a data frame and arrange the layers in this order from bottom to top: 1) World30_dissolved, 2) Country, 3) World30.
5. Symbolize the data as follows:
• World30 – Fill color: No Color; Outline color: 80% gray, Outline width: 0.40 points
• Country – Fill color: White; Outline color: No Color
• World30_dissolved – Gradient Fill Symbol, Intervals: 100, Percentage: 95, Angle: 90, Style: Circular, Color Ramp: The color ramp you created to fill the ocean.
  
  
  
6. Project and symbolize the data frame:
• Use the World from Space projection (this projection is in the Projected Coordinate Systems folder, in the World sub-folder).
• Make the following modifications to the longitude of center and the latitude of center to show the western seaboard of the U.S. (you can modify the latitude and longitude of center to show other locations on the Earth):  Longitude of Center: -150.0, Latitude of Center: 25.0.  To make these modifications, on the Data Frame Properties Coordinate System tab click the Modify… button after you have selected the World from Space projection.
  
  
  
• Set these data frame properties: Frame – Border: None; Background: None

Add your area of interest (optional):

There are two ways to do this – with a feature class that uses a Definition Query or with an Extent Rectangle.

• Feature class that uses a Definition Query:
• Add the feature class to the locator map data frame.
• Write a Definition Query to ONLY display the feature (or features) of interest.
• Symbolize with: Fill color: Black; Outline Color: Black, Outline Width: 1 point (you can vary this depending on how well you can see the features on your map – a wider outline will show smaller features more clearly, but don't make the line so wide that you exaggerate the location too much -- you don't want to give the impression that the area is massively larger than it really is.
  
• Extent Rectangle:
  • Add an Extent Rectangle for another data frame to show its location on your locator map.
  • Use these frame properties: Border: 1.0 point, Color: Black.
    

Export the data (optional)

1. Right click each feature class in the projected locator map data frame and click Data -> Export Data.
2. Select the option to Use the same coordinate system as: the data frame, and click OK.
3. Do not add the exported data to the map as a layer.
4. For each layer in the locator map data frame, right click the layer, click Properties, click the Source tab, click the Set Data Source button and select the exported data that has the data frame’s projection.

Hopefully, you now have a nice looking locator map for your main map!

One of the presentations we gave at this year's User Conference was "The One Minute Cartographer". While we were developing the presentation, we had several intentions in mind. Most importantly, we wanted to demonstrate to the attendees of our session that making a good map in ArcGIS isn't always as hard as it seems – often times, it is just a matter of going one or two steps beyond the defaults. Another thing that was really important to us was to make sure that all the data we used to produce this map was also available to you, so we used data on the ESRI Data and Maps DVD. In addition, we wanted to create a set of resources with great potential to help map makers in a variety of ways:

1. it could be used by teachers to demonstrate and explain how to make a map in ArcGIS,
2. portions of the presentation could be used as labs in GIS and cartography classes,
3. professionals or students could run through the set of instructions to update or test their map making skills,
4. newcomers to the software could use the resources to get up to speed in map making, and
5. you could use the instructions to create the same kind of map for your own local area.

All of the resources you need to create the map of Washington Elevation are available on the Mapping Center website. Click on the Other Resources tab at the top of any Mapping Center page, and the first tabbed page contains a list of all our presentations. You will find three downloads to the resources you need to make this map:

1. WashingtonElevation_Presentation.zip -- this zip file contains a PDF version of the presentation we gave at the 2009 ESRI International User Conference in the "One Minute Cartographer" session. The bottom notes of the presentation include all the instructions necessary to make the Washington Elevation map.
2. WashingtonElevation_Documentation.zip -- this zip file contains the PDFs of three maps -- the Washington Elevation map that we demonstrated how to make in our "One Minute Cartographer" presentation, an enhanced Washington Elevation map to which we added a locator map, physiographic feature labels, summits and their labels and gradient fill in the ocean. We also included a map that our colleague, David Barnes, made of the same area using the same data but a different affective design.
3. WashingtonElevation_ArcGIS_Resources.zip -- this zip file contains the data and other resources necessary to create the map in ArcGIS that we demonstrated how to make in our "One Minute Cartographer" presentation. Specifically, this file includes:

• WashingtonElevation.mxd – an ArcMap document that was used to create the map. The Washington Elevation data frame contains the data used on the final map. The “Demo Data” data frame contains intermediate data used to create some of the cartographic effects in the final map.
• WashingtonElevation.gdb – the file geodatabase used to create the map.
• WashingtonElevation.style – an ArcMap style that contains the color ramps used to symbolize the hillshade and layer tint on the map, as well as the point symbols used for cities and the line symbols used for boundaries.
• WashingtonElevationBookmarks.dat – the bookmarks used in the WashingtonElevation.mxd.
• WA_HydroPolys_Lakes.exp – the SQL query used for the WA_HydroPolys:Lakes label class to label only the lakes within the state of Washington.
• USHydroFlowLines_1.exp – the SQL query used for the USHydroFlowLines:1 label class to not label the streams outside the state of Washington.

Together, these resources provide everything you need to create the Washington Elevation map. The original data sources are documented on the General tab for each layer in the map document. As we said above, all data came from the ESRI Data and Maps DVD. So you can easily re-create the map for any location that is covered by data on the ESRI Data and Maps DVD.

We said in the presentation, "A map is always done when you run out of time!" Using the tips and tricks we outlined in the presentation, we hope we can help you can make the most of your time. If you have extra time, and energy, we encourage you to add any final touches to the map or make any enhancements that you see fit. We’d love it if you would tell us about your work here so that it can be shared with others! You can use the Comments option at the end of this blog post to let us know what you’ve done. Or you can ask for any clarifications, if you need them – in the comments or on the Ask a Cartographer page. We look forward to hearing back from you!

Note -- we will be posting an enhanced version of this map on the Maps page of Mapping Center in the very near future.  Look for more instructions there on how to achieve more great cartographic effects with this map!

Save the representation rules from the template geodatabase 

1. Add the "Faults" feature class from the GeologicMap feature dataset in the ESRI_Geology.gdb to a new ArcMap document. 
2. Right-click on the Faults layer in the Table of Contents, select Properties and then Representations on the Layer Properties Symbology tab. 
3. Select a fault symbol ("2.1.1," for example) and then click the lower right arrow below the column of symbols and choose "Save Rule." The rule is then saved to the “Representation Rules” folder in your personal style. 
4. In "Save Rule to Style" window, name the symbol. You can accept the default name (2.1.1 in this example), or rename the symbol. 
5. Repeat steps 1-4 procedure for all symbols you need from any of the feature classes in the template.
   
6. In ArcMap, click New Map (prevents locks).

Create representation class and add symbols 

1. Add your feature class to the empty map document. 
2. Create a representation class for your feature class. (Right-click layer and select “Convert Symbology to Representation”.  This will create a simple representation class with the default symbology). 
3. Open Layer Properties and select Representations on the Symbology tab. 
4. Click the black arrow again and select “Load Rule.” 
5. Scroll down until you see symbol 2.1.1 in Representation Rule Selector window. 
6. Name the Rule. The default name is Rule_1, Rule_2, etc. 
7. Repeat as needed. Note the Rule IDs (the number in brackets [2]) for each symbol); you will need to know these to symbolize your data. 
8. Click OK when finished.

Assign Rule ID to features 

1. Start Editing. 
2. Select all faults in your feature class that should be symbolized with the 2.1.1 symbol. 
3. Calculate the Rule_ID field with the Rule ID using the Field Calculator in the Attribute Table or if it is just one or two features, use the Attributes window.  Symbol 2.1.1 in this example was the first Rule loaded to the new representation class. Therefore, the calculated value should be 2, as the Rule ID for the first rule loaded using this method will always be [2].

This procedure can be applied to any representation symbol you want to move between geodatabases that support representations.

A common question that we get on Mapping Center is how to create an elevation legend in ArcMap. In September of 2007, there was a blog entry on Mapping Center (Creating a legend for hypsometrically tinted shaded relief) that outlined a method for creating a legend for hypsometrically tinted shaded relief. When that blog was written, the option to Convert Graphics to Features was not yet available. This blog outlines a simpler method for creating an elevation legend using this new option (version 9.3 and later).

1. Creating a graphic for the legend

   To use the Convert Graphics to Features Option, you have to be in Data View. On your completed map, choose a location where you want your elevation legend to appear, and draw a rectangle using the New Rectangle tool on the Draw Toolbar.

   

2. Converting the graphic to a feature

   Once you have created your graphic rectangle, select it and then right click on the name of the active data frame and select the Convert Graphics to Features option. Use the option to use the same coordinate system as the data frame, and specify the output location of the feature class. You can also check the option to automatically delete graphics after conversion, or you can delete it manually once the features have been created.

   Click OK and choose the option to add the exported data to the map as a layer.

   

3. Symbolizing the legend

   You will need two copies of the converted graphic feature class for your legend. The bottom copy will be symbolized the same way you symbolized the hillshade on your map (this usually involves only specifying the color ramp), and the top copy will be symbolized the same way you symbolized the layer tint on your map (this usually involves specifying the color ramp and the amount of transparency).

   In the Table of Contents, right click the feature class, click Properties and click the Symbology tab. Click the color patch and then click the Properties button in the Symbol Selector dialog to get to the Symbol Property Editor. Here, change the Type to Gradient Fill Symbol and leave the default Style as Linear. Select the same color ramp you used to symbolize your hillshade. Change the Intervals to 100, the Percentage to 100, and the Angle to -90. (This is if you are creating a horizontal legend – the angle would be 0 if you were creating a vertical legend.) Click OK twice and then click Apply to see the changes. Check to make sure that the darker color is on the bottom and the lighter color is on the top – if they are reversed, go back and change the Angle to 90. Otherwise, click OK.

   

   Once you have this feature class symbolized, right click it in the Table of Contents and click Copy. Then right click on the name of the data frame and select Paste Layer(s).

   Now right click the top copy and click Properties. On the Display tab, change the transparency to the same transparency level as the layer tint on your map (in our case it was 40%). Then on the Symbology tab, click on the symbol patch and click Properties. Select the same color ramp you used for your hypsometric tint. and change the Angle to 0. (If you are creating a vertical legend, the angle would be 90.) Click OK twice and then click Apply. Check to make sure that the lower elevation colors are on the bottom and the higher elevation colors are on the top – if they are reversed, go back and change the Angle to -90. Click OK to keep these changes.

   

4. Adding the legend text

   At this point, you can switch to Layout View to add the text to your legend. There are two options for creating the text for your elevation legend. Both use the New Text Tool on the Draw Toolbar and both will place the text in an annotation group. The difference is that you can choose to associate the text with the legend feature class so that if you turn this on or off in the Table of Contents, the text will also turn on or off.

   With the first option, you simply place the text in an unfocussed data frame. With the second option, you create the new annotation target and you specify that this is where you want the text to go. Then you place the text in a focused data frame.

   To use the second option, in the Drawing menu located on the Draw Toolbar, select New Annotation Group. In this dialog box, specify a name for the new annotation group (for example, "Legend Text"), and then select the Associated Layer (the feature class that you created when you converted the graphic rectangle to a feature). You can also set a reference scale and scale range, if you want. Click OK to accept your selections.

   

   Before you place your text, double click your data frame in layout view so it becomes focused (you will know it is focused when you see hashed lines around the frame of your map).

   Click on the Drawing menu of the Draw Toolbar and under the Active Annotation Target make sure your newly created annotation group is checked on. You can then begin using the New Text tool to add the elevation values and units of measurements to your map. When you are done, you can check that this works right by turning off the legend layer in the Table of Contents – the legend text should also turn off.

You should now have an elevation legend that corresponds to the right colors for elevation values on your map!

Depending on the type of highway you are labeling (interstate highway, U.S. route highway, or state route highway), the standard highway shield symbol may or may not be wide enough for all the characters in your labels.

Often, you do not get the desired outcome by simply using one shield for all highway number labels because one size rarely fits all! The numbers look “squished” or they overrun the shield symbol when there are more than two characters (depending on how large you make the shield and the characters).

Here are some tricks you can use to create highway shields for labels of varying widths, especially when there are more than two characters in some of the highway names.

A. Preparing your data

Often the field that contains the name you want to appear in the shield also has other characters in it. You need a label field that ONLY contains the numbers that will appear inside of the highway shield.

In Figure 1, ROUTE_NUM is the original attribute and HWY_LABEL is the field that is used to label the highway shields.

Figure 1: the HWY_LABEL field is used to label highways.

There are two steps to setting up this label field: 1) adding the label field, and 2) using a special tool to populate it.

1. Add a label field

   First, add a text field to your attribute table that is at least as long as the longest number that will show in your highway shields.

2. Populate the label field

   Second, download the Label String Management Tools from the ArcScripts download Web site. In the download, there are some things you may want to take a look at including the contents of the Doc folder and the readme.txt file.

To load the toolbox into ArcToolbox, right click on the ArcToolbox icon. Select Add Toolbox and navigate to the folder into which you downloaded the Label String Management Tools. Click Label Text Tools and click Open. The Toolbox will now appear in ArcToolbox.

In the newly added Label Text Tools toolbox, in the Custom Field Calculators toolset, open the Extract Hwy Numbers for Hwy Shield Labels tool. This tool populates the label string field that you added with the text that will be shown in the highway shields. For example, if the highway name is "10", the tool will populate the new label field with "10".

3. Add the highway type field

   If you are going to be using different highway shield symbols for different types of highways, you need a field in your attribute table that identifies what type of highway each feature is. Ours is "Class", and it identifies interstate highways as "I", state route highways as "S", and U.S. route highways as "U" (see Figure 1).

Now that your data are ready, you can create the labels.

B. Create the labels

1. Create multiple label classes

   The next step is to create different label classes for each type of highway of each label length. This is most easily done in Label Manager (Figure 2). The following examples use the Maplex Label Engine. Depending on your data, you could have up to six classes if you have interstate highways, state route highways, and U.S. route highways with names that are 1-2 characters long and 3 or more characters long. 



Figure 2: Label Manager can be used to create the label classes.

In our example, interstate highways can be 1, 2, or 3 characters long. Cartographically, the desired result is to have one highway shield that can be used for interstates that are 1 or 2 characters long and a second shield for labels with 3 characters. (There are no interstates with names that are more than 3 characters).

The same would hold for highways other than interstates. In those cases, the number of characters might even be more than three. You would need to create a label class for each unique combination of highway type and number of characters.

In our example, we created two label classes in Label Manager:

• Interstate_Shield – this is used for interstates with names that are less than 3 characters long.
• Interstate_WideShield – this is used for interstates with names that are 3 characters long.
  
  
2. Create the highway shield symbol for interstates with names that are less than 3 characters long

   The EASIEST way to create these symbols is to select them from the Symbol Selector and then make any edits you need to make. We want a symbol like the U.S. Interstate HWY symbol (Figure 3), but we want it to have a white fill with a dark gray outline. So in Label Manager click the Symbol button to select this symbol, and then click Properties in the Symbol Selector to make some changes.



Figure 3: There are a number of highway shields in the default ESRI Style that you can simply modify.

There are a number of dialog boxes you need to navigate through to get to the point where you edit the highway shield symbol. Follow these steps to get there:

• With your label class highlighted in the Label Manager window, select Symbol.
• In the Symbol Selector window, click Properties.
• In the Editor window, click the Advanced Text tab and make sure Text Background option is checked.
• Click the Properties button located under Text Background.
• In the next Editor window, click Symbol.
• In the Symbol Selector window, click Properties.

Now you will be able to edit your highway shield symbol.

3. Edit the highway shield symbol

   You can click on the symbol layer and change any properties you want to – we changed the two fill symbols to white and the outline to dark gray (Figure 4).



Figure 4: The multi-layered symbol can be edited to appear as you like.

Click OK twice to accept the changes you made.

Note: At this point, note that the Editor dialogue box you have the option to "Scale Marker to fit text". If you use this option, you will scale the symbols in both the x and y dimensions so that they fit your text (Figure 5). This is NOT usually the effect that you want, but if you are in a hurry it is a better option than having your text overrun the shield symbol. The better option is to use a different symbol for the highways with longer names. This is pretty easy once you have the first label class set up.



Figure 5: The "Scale Marker to fit text" option increases the height of the shield symbol as well as the width.

Click OK again to accept the changes and return to the first dialog box in Label Manager.

4. Set up the label class SQL queries

   The last step in setting up this label class is to specify that you will use these rules to ONLY label the interstate highways that have names that are less than three characters long.

   On the first dialog box of Label Manager, click the SQL Query tab and type in the following SQL query (the operator CHAR_LENGTH searches the character length of a given field):

   

   Click Apply to see the results.

5. Create the highway shield symbol for interstates with names that are 3 characters long

   Since you now have one of the label classes set up, you can right click it and select Copy Parameters. Then right click on the second label class and select Paste Parameters.

   All you have to do now is to change the SQL query and edit the shield symbol. The SQL query for this class is:

   

   Now edit the symbol to make these changes (Figure 6):

• Change the font to ESRI Shields.
• Change the symbol for the dark gray outline to the symbol with Unicode value 94.
• Change the symbol for the white fill to the symbol with Unicode value 91.



Figure 6: A few minor edits will result in a highway shield that can be used for labels that are 3 characters long.

You should now have two types of highway shields for labeling your interstate highways. For labeling other types of highways, follow the same methodology using different shield types and adjust the second query to be >= 3 as some U.S. Route and State Route highways are more than 3 characters long.

This might seem like a lot of hoops to jump through but the result should be really good looking highway shields on your map. And of course you can always save the feature class as a layer file and reuse the symbology and labeling on your other maps!

All of us on the Mapping Center Team were at the ESRI International User Conference in San Diego, California this past week (July 11-17). We taught Tech Sessions, we demoed our online map services, we had meetings with users, we attended sessions, we judged maps, we promoted books, we solicited feedback on our work, and we made connections for future projects.  We also got to see many people we know and to make new friends!

We thought you might like to hear what the highlights of the conference were from our perspective, but we'd love to hear what you thought about the conference, if you were able to be here. Please take a moment to add a comment so we can hear from you!

For those of you who weren't able to attend, many of the conference sessions have been taped and will be available to you on the ESRI web site in the near future!  And all of the presentations of the Mapping Center Team will be posted on our Other Resources - Presentations page within the next week.

So here were the highlights for us:

• More than one of us said the highlight was when people realized that some of the things you can do with ESRI software to make great looking maps are really not hard at all!
• For me, one of the highlights was learning that there is a Student Resources link for the Map Use book that includes for every chapter the PowerPoint presentation (every graphic in the book is on a separate PowerPoint slide!) as well as the exercise so they can simply download them from the Web site for their classes. (For teachers, there is a Teacher Resource CD with the answers that we can send to you.)
• Since we have been making so many maps lately, especially for online map services, it is not surprising that some of us felt that one of the highlights was seeing our maps in demos and used as examples to show people how to get their information online and out to a wider audience.
• For me, one of the highlights was meeting some of you who have written to us on Ask a Cartographer. In fact, one person came up after a session to ask if you could use fractions in scalebars (right now you can't, so we'll write a blog entry on how you can achieve this effect nonetheless!) Because we have been here at the UC this past week, we didn't respond as quickly as we usually do, so I was able to answer him in person -- a real treat!
• One person said that the highlight was getting the whole room to laugh while he was presenting in a Tech Session -- that indicated to him that people were relaxed and not intimidated by what he was trying to teach them.
• Another person said that the highlight was getting good feedback after her presentation. We all work really hard to put together our demos and talks -- since technology is involved, you sometimes don't know how things will turn out, so it's always nice when it all comes together in the end!  And it's even nicer when the audience members let you know what they thought about how you did.
• For many of us, one of the major highlights was seeing colleagues, former students, and friends that we have not connected with for a while -- one person unexpectedly ran into a buddy of his from graduate school that he hasn't seen for 18 years! It was exciting to see so many of you doing really interesting and important things in your jobs, and to learn that you are still making your great maps!
• For all of us, one of the other highlights was getting to know new people -- for me, these were the folks from The Nature Conservancy and the USDA Natural Resources Conservation Service --  we are really looking forward to working with them in the coming months to make their maps and data "come to life" (as Clint put it) on the Web.
• Finally, for me, one of the other conference highlights was seeing Jon Kimerling walking through the Map Gallery on opening night with the "Meet the Authors" sign for our new Map Use book -- as he carried the sign over to the Academic Fair area, people started following him like he was the Pied Piper! We don't know if it was because he was laughing the whole way, because they might have known him and wanted to talk to him, or they really did want to "meet the author"!

Next week, it's back to Redlands where we'll be working full time on Mapping Center again!

In the next couple of blog posts, we want to explain a bit about the two tools you can use to create buffers in ArcGIS. Buffers are used not only in analysis of distances and areas around point, line and area features, they are also used in mapping to achieve a number of cartographic effects, such as coastal vignettes. Since there are two tools and multiple methods you can use to create buffers, and each have their particular strengths and weaknesses, we thought it would be good to review these for you. In the next couple of blog posts, we'll describe the tools and methods, how they differ and what you need to consider when using them.

As an introduction, this tool review is an extension of the work that our colleague, Tom Bole of the ArcMap Team, did a few years ago in response to the map that appeared in The Economist on May 3, 2003. This map showed the countries that can be reached by North Korean missiles with different ranges.

The map was corrected in the May 17 issue of The Economist.

The buffers in these articles are clearly for analysis purposes, so knowing how they are generated and how accurate the results are is imperative. Although there is a little more leeway with buffers for cartographic effects, it still behooves the good map maker to know how ArcGIS create buffers. So this first blog post focuses on the Buffer Wizard. In the next one, we’ll discuss the Buffer Tool in ArcToolbox, as well as the variations between the two tools. (Thanks to Tom for the map graphics in this blog!)

The ArcMap Buffer Wizard functions evolved from tools developed for the ArcView GIS 3.x environment. By default, The Buffer Wizard uses a temporary on-the-fly projection to minimize distortion in the output buffers. Many users migrating from ArcView GIS 3.x to ArcGIS Desktop are not aware of the effects of spatial reference on buffer results, and might not adjust the spatial reference of the ArcMap Data Frame to an appropriate coordinate system. The default setting of the Buffer Wizard adjusts for this by using a temporary coordinate system to construct geometrically correct buffers.

To add the Buffer Wizard to ArcMap, go to Tools > Customize > Commands tab. In the Categories window on the left, scroll down and select Tools. From the Commands window on the right, select the Buffer Wizard tool, then drag and drop the tool onto any toolbar displayed in the ArcMap window (Figure 1).

Figure 1. Location of the Buffer Wizard tool in ArcMap.

In ArcGIS Desktop versions 8.3 and earlier, the Buffer Wizard was included in the Tools dropdown menu, but was moved to the Customize dialog at 9.0.

How the Buffer Wizard works with coordinate systems

The ArcMap 8x Buffer Wizard uses a temporary spatial reference system called the Buffer Processing Coordinate System, or BPCS, when creating buffers. There are four options available for the BPCS, and you can change the setting in ArcMap Advanced Settings Utility > Miscellaneous tab. Figure 2 illustrates one page of this dialog.

The utility is located in the ArcGIS install folder at \Utilities\AdvancedArcMapSettings.exe. ArcMap must be closed in order to open the dialog. Administrative permissions are required to change settings, because entries change Registry settings on the computer. Any changes should be made with caution.

Figure 2. The ArcMap Advanced Settings Utility dialog Miscellaneous tab, with the Buffer processing coordinate system options displayed in the dropdown. "Feature set optimized coordinate system" is the default setting for the Buffer Wizard when ArcMap is installed.

Here is a detailed description of each option for the Buffer Processing Coordinate System:

• Feature set optimized coordinate system – This is the default setting. The BPCS is based on the spatial distribution of the buffered features. A temporary Hotine Oblique Cylindrical projection is calculated based on the position of the features being buffered. Once the buffer is created, the buffers are reprojected and saved in the coordinate system of the ArcMap Data Frame. This setting helps minimize distortion regardless of the spatial reference of the Data Frame. If you are buffering from a selected subset of features, the centerline of the temporary projection is calculated using the subset of features.
  
• Feature optimized coordinate system - A BPCS is created for each feature being buffered, and each is based on an azimuthal equidistant projection created for each separate feature. For lines and polygons, the center point of each feature is calculated. Once created, the buffers are reprojected and saved in the coordinate system of the ArcMap Data Frame. This setting also helps minimize distortion regardless of the spatial reference of the Data Frame. Though performance will be slower with this setting, it does offer the least distortion when buffering point features.
  
• Coordinate system of the data frame (output) - The BPCS is based on the coordinate system of the Data Frame. Accuracy of the buffers will depend on how appropriate the coordinate system of the Data Frame is for the features being buffered. To obtain maximum accuracy for buffers using this setting, the ArcMap Data Frame needs to be set to a custom equidistant projection with parameters defined to center the coordinate system in the middle of the data. For more information on different projections and their properties, and creating custom projections in ArcMap refer to Knowledge Base articles 24646 and 30583 on the ESRI Support Center (http://support.esri.com/).
  
• Coordinate System of the feature class (input) - The BPCS is based on the coordinate system of the features being buffered. Once created, the buffers are reprojected and saved in the coordinate system of the Data Frame. Accuracy of the buffers will depend on how appropriate the coordinate system of the feature class is for the features being buffered, as well as the coordinate system of the ArcMap Data Frame.

Given the information above, you will need to decide how you want the Buffer Wizard to perform, and what results you need when you buffer features. Here are some issues to consider that primarily pertain to buffering points, but apply to buffering lines and polygons as well.

People instinctively expect buffers around points to be round. However, if the ArcMap Data Frame is set to a Geographic Coordinate System like GCS_North_American_1983 or GCS_WGS_1984, buffers that are geometrically correct, and measure the same distance from the center point to the buffer in any direction, will display as ovals.

Is your map being prepared for GIS professionals who will understand the buffer display, and how the buffers may be “stretched” east to west if a Geographic Coordinate System is applied to the Data Frame?

Is your map being prepared for people who are not well-versed in GIS principles, and will expect to see round buffers? If this is your situation, it would be advisable to change the projection of the ArcMap Data Frame to a projected coordinate system that used units of meters or feet. This might be UTM, State Plane or another projected coordinate system. Changing the projection of the ArcMap Data Frame will result in the geometrically correct buffers displaying as round circles, meeting expectations for people who will be viewing the map.

The examples below, created using large buffer distances, demonstrate some of the visual distortions introduced when displaying buffers in a Geographic Coordinate System, as well as the inaccuracy introduced when creating buffers when the calculation is based on a GCS.

Buffer Wizard Test using ArcMap

Three buffer rings of 5,000 km each around a point (Pyongyang) and polygon (North Korea) were created using 3 different BPCS settings and 2 different Data Frame coordinate systems.

In order to assess the accuracy of the buffer, major world cities are labeled with their great circle distance to Pyongyang (125.941074 E, 39.785978 N). The distances were taken from the following website - http://www.wcrl.ars.usda.gov/cec/java/lat-long.htm.

BPCS: Coordinate System of the Data Frame
Data Frame Coordinate System: GCS_WGS_1984

Figure 3. These buffers are not accurate. Only Johannesburg is within the correct buffer ring (10,001-15,000). Buffering from the North Korean polygon gives similar results. Even though the buffer rings display as the expected circles, the buffer distances from Pyongyang are not correct.

Notice in this world view, displayed in a Geographic Coordinate System, that the North and South Poles, which are points, appear as long as the Equator. This "stretching" of data always occurs when data is displayed in a GCS. At the Equator, 1° east to west measures approximately 69 miles. At the North or South Pole, 1° measures 0 miles, since the Poles are points. The distortion in data display increases with distance north or south of the Equator.

BPCS: Feature optimized
Data Frame Coordinate System: GCS_WGS_1984

Figure 4. These buffers appear to be correct. Buffering from the North Korean polygon gives similar results. Notice, though, the difficulty that might occur when viewing the buffers as shown in this map. Even though the buffer rings are geometrically correct, the distortion in the buffer shapes introduced by displaying the buffers in a Geographic Coordinate System might defeat the purpose of the map for the intended audience. Compare with the display of these buffers shown in Figure 7.

BPCS: Feature set optimized (temporary Hotine projection)
Data Frame Coordinate System: GCS_WGS_1984
Buffer from point

Figure 5.  These buffers are not correct.  Note that in comparison with the great circle distances shown in the table, the cities do not lie within the correct buffer rings.

BPCS: Feature set optimized (temporary Hotine projection)
Data Frame Coordinate System: GCS_WGS_1984
Buffer from polygon

Figure 6. These buffers are inaccurate. Buffering from the North Korean polygon gives different results, also incorrect. Buffering at these distances creates problems for the temporary Hotine projection, and this is a limitation of this buffer processing method.

BPCS: Coordinate System of the data frame
Data Frame Coordinate System: Azimuthal_Equidistant

Figure 7. These buffers appear to be accurate, and visually present the buffers in a way that is easier to understand and interpret than the presentation in Figure 4.

BPCS: Feature optimized
Data Frame Coordinate System: Azimuthal_Equidistant

Figure 8. These buffers appear to be accurate.

BPCS: Feature set optimized (temporary Hotine projection)
Data Frame Coordinate System: Azimuthal_Equidistant

Figure 9. These buffers are inaccurate. Buffering at these distances creates problems for the temporary Hotine projection, and this is a limitation of this buffer processing method.

Conclusions

1. The default processing for the 8x Buffer Wizard has issues with large distances at the world scale. This is a limitation of using a temporary Hotine projection.
2. The best result was achieved by using the Feature optimized option.

   BPCS: Feature optimized
   Data Frame Coordinate System: GCS_WGS_1984

   

   BPCS: Feature optimized
   Data Frame Coordinate System: Azimuthal_Equidistant

   

Last week we started telling you about the new ArcGIS Online World Topographic Map. As I was working on the design of that map, with the intent of providing a better basis for mash-ups, I had an idea. It was born of frustration with the fact some mash-ups don't work because too much information obscures the base map, making for an unreadable, often ugly result. Demographic layers represent a great example of the kind of information that just doesn't always work well in a simple mash-up.

What I really needed was a way to "sandwich" the demography layer between the terrain and the reference information--that way the reference information would be legible, and I would still be able to understand the demography. The two images below illustrate the inadequacy of a conventional mash-up and how what we've loosely been calling a "map sandwich" produces a better result.

Mash-up where base map is obscured.                  Map sandwich with legible base information.

The idea is to make a map that looks more like a map than a mash up.  

How the Map Sandwich Works

The basic idea is that three map services are stacked on top of each other to create a map:

Top Layer:  This layer is the reference information that contextualizes the middle layer. We've found there is only one option for caching this layer, which is to use the new .MSD file option in ArcGIS 9.3.1.  We use the PNG32 image format, and set the .MSD options for anti-aliasing to "None", and text anti-aliasing to "Forced".  This layer is cached. Note that using the .MSD file for caching means that cartographic representations and Maplex cannot be used--we used annotation for our text.

Middle Layer: The theme for this layer could be nearly anything--demography is just a straight-forward example. A statistical surface, scientific information like soils, geology, etc. could be used here.  When this layer is incorporated into a map sandwich, it is usually partially opaque (the {opacity:0.5}) or something similar appears in our JavaScript code's layer definition.  We've cached these layers as PNG8, PNG32, and JPEG--all worked fine, so our decision was based on file size.

Bottom layer:  Typically this is terrain and optionally oceans or contours.  Our first effort does not include contours.  We cached this service using the JPEG image format, though there is really no restriction about the format for this map service.

So here is a map that allows you to turn the layers of a map sandwich on and off to see, at a conceptual level, how a map sandwich is built.

Here is another example that was created by Kenny Ling from the Mapping Center Team (web application), Jessica Acosta Rodriguez from the ArcGIS Online Team (cartography for demography), and Jim Herries from the ESRI Data Team (the data) that further develops this same idea using some of ESRI's newest demographic data.  After the map loads, click the Theme button and choose a demographic variable. You can then click on the map to get a report.

Map Sandwich Demographic Example

If you've never used the ESRI JavaScript viewer before, knowing that you can use SHIFT-drag to zoom in, and CTRL-SHIFT-drag to zoom out, makes a big difference.

The map services that make these maps work are available at ArcGIS Online; just scroll down to the "Web Merctor Maps" section.  Specifically we used the World Terrain Base as the bottom layer, and the World Reference Overlay as the top layer in our map sandwich.  Any of the demographic layers can be used as middle layers.

If the demographic data piqued your interest, ESRI's demographic data has thousands of additional attributes; a veritable "data deli".

Most of the Mapping Center Team will be at the ESRI International User Conference in San Diego, California over the next week (July 11-17). If you’re there, look for us in the following presentations:

• The One Minute Cartographer - Aileen Buckley and Mamata Akella
• Map Use Book Series - A. Jon Kimerling and Aileen Buckley
• Local Government Basemaps using ArcGIS - Charlie Frye and others (Scott Oppmann and Steve Grise)
• ESRI Geologic Mapping Template - Charlie Frye and Janel Day
• Map Use: Reading and Analysis - A. Jon Kimerling and & Aileen Buckley

We'd love to meet you and hear what you think about Mapping Center. We will still be psoting blog entries while we are gone. Our travels will, however, impact our ability to respond rapidly to your Ask a Cartographer questions. Don’t let that stop you from sending them, though -- we’ll do our best to get to them as soon as we can.

The Mapping Center Team is pleased to share the ArcGIS Online News announcement that includes the availability of the new World Topographic Map. As several members of the Mapping Center team played a significant role in the design and production of this map, we would like to begin telling you about this map. The World Topographic Map covers the globe to about 1:1,000,000 scale. Within the U.S. (excluding Alaska), the map scale extends to about 1:18,000. The map is a cached map and uses the Virtual Earth/Google Maps tiling scheme (WKID = 102113). What follows are some of the essentials everyone should know about this map, including that the service is free.

As with any map, we start with the audience -- you -- the ArcGIS user who needs a topographic base map and doesn’t have the time, data, or training to make one. The purpose of the map is to provide a base to underlay and geographically contextualize your GIS data content.

The map is designed to be mashed up on. We purposefully omitted the darkest and brightest colors from the map so you could use those colors to symbolize the data you will be overlaying on this map. As a result, the "unadorned" view of this map looks a little washed out. Here are a couple of  examples:  flood plains in Sioux City, IA and hydrologic units with NWIS and STORET gauging stations. (Click on the images to see the full size versions.)

The World Topographic Map was created using best available data. We will improve this map over time as we learn of and acquire better data. More candidly, this map is, and will be a community-wide effort, with ESRI facilitating the compilation of uniform cartography. We want to work with any of you who have better data, and we'll cover more about how that will work in upcoming blog entries.

Like most online maps, the quality of the map can be largely attributed to the community of data providers. In particular, the U.S. Geological Survey’s EROS Data Center provided terrain and land cover data, and the U.S. Environmental Protection Agency, with assistance from the U.S. Geological Survey, provided NHDPlus hydrography data. Without these data sets, the World Topographic Map would not have been possible and thus, we are greatly indebted to these organizations. There were many other organizations that also produced data we used, and the REST endpoint of the map service gives credit at the service level and at each map scale. We are also in the process of compiling a more accessible list of data sources.

In addition, we have developed some ESRI JavaScript Viewer examples that use the World Topographic Map. The links below show the map with a pop-up that displays the topographic characteristics within the continental U.S. and Hawaii. The reported information is derived from slope, aspect, and elevation layers in the World Topographic Map service. Take a minute to browse the samples to see the extent and scales of the map as well as the viewer samples. (You'll know you're at the detailed scales for Portland and Philadelphia when the buildings have drop-shadows).

World Topographic Base Map - ESRI JavaScript Example

World Topographic Base Map - ESRI Virtual Earth Example

If you use the Virtual Earth Example and have not yet downloaded the Bing Maps 3D (beta), here is an example of what this map looks like in 3D (Click to see full size view of Mount St. Helens):

There's a lot more that could be said about the World Topographic Map and its related map resources, but first we simply wanted to alert you to its release. We'll be writing more about specifically how we symbolized, labeled, and compiled this map in future blog entries.You can also visit the ArcGIS online hopepage for the World Topographic Map.

We’ve posted our recently revised Color Ramps version 2.0 styles on our site to be more suitable for your use. Our impetus was we needed something new to work on a project. We were working on a printed map of Washington Landforms that we will talk about in our "One Minute Cartographer" session at the ESRI User Conference this year. This presentation will be posted on the Mapping Center - Other Resources page after the conference. The color ramp used on this map was selected from the PNW_x set in the new Hypsometry style. (PNW stands for "Pacific Northwest".)

Basically, we found that our previous version of Color Ramps was now cumbersome and as such due for some streamlining. So, here's what happened in a nutshell. We had a desired result for the design in mind when we started. It's worth mentioning that we often admire the Raven Maps style of hillshade, certainly an inspiration for the final results, but not the only source for all the Color Ramps. Since we were changing one style why not go ahead and try for a more sensible approach with the contents of the remaining ones as well? We removed duplicates, arranged related groups and made sure that the category field was empty. The category field for color ramps is a known issue -- if you fill it, the ramps become unavailable.

From Several Color Ramps to Four Choices

With the design focus settled, we evaluated what the themes were for the styles and chose:

1. Hypsometry - where we batched up both terrestrial and bathymetry ramps -- that's where we started and where the Washington Landform color ramps were added;







2. CartoEffects - used for gradiant borders [see the Crater Lake map];



3. Events - which became significantly larger - but we dedicated the style to be used for environmental events, such as Active Fires, Gradual events like desertification, Seasonal and Water Events;



4. Hillshades - where we placed ramps that are used to create Area Specific hillshades - that could be mono or bicolor, multi or for lighting effects.

Using a Existing Color Ramp to Make a New One

Do you need to start from scratch every time you make a hillshade color ramp? No, but you do need to consider what you're using and make copies of existing ramps to use as your work-in-progress. One example is the specific area ramp that started this process. We took an existing style from version 1.0 and copied it into the new version, in this case we started with the Ramp named Europe_Italy. We kept the structure of the five algorithmic color ramp, and that was important because we already had our map project very near completion --and the hillshading was already established as the five part ramp. If we changed the numbers for the structure at this point, we would have a substantial amount of editing to do from a color aspect. So we made a series of modified ramps starting with the name PNW_1.00 and continued to make several variations. Here is some online help for working with color ramps.

How fast can you cache?  We keep asking ourselves that and keep finding that the more we know the faster we cache.

If you’re involved in the job of caching maps for online map services, you are already familiar with the need to optimize the process as much as possible so that it takes less time and effort. One way you can do this is to optimize how your maps are displayed – another is to optimize the environment you are caching your map in or the circumstances under which you are caching. This blog post is dedicated to the latter.

Here is what we’ve learned in the past few months:

1. Upgrade to ArcGIS 9.3.1. If you have not upgraded to 9.3.1, do it before caching because the file I/O for writing map cache tile images was vastly improved in the latest version. The result is anywhere from 25% to 2000% faster caching. Basically, the simpler the map, the more improvement you’ll see. That’s because simple maps draw faster and therefore file I/O is a larger proportion of caching time.
2. Use more than one computer to cache. If you have the luxury of using several computers to do your caching, break up the caching job first by map level, and, if needed for the largest scales, geographically. Each portion of the job should be done such that tiles are being written to each of the several computers’ hard drives. When the caching is done, then copy the tiles from each machine into a master cache. One tip here is that we bought a software application called Secure Copy by ScriptLogic Corporation which made the job of copying possible for the largest scales where the potential exists to produce millions of map tiles.
3. Set the number of processes to two. We’ve found that two is the optimum number of processes on each computer doing caching (we’ve been using 2 Duo CPUs E8500s each with 4Gb of RAM). One process just doesn’t take full advantage of available CPU and memory. Three processes pin the CPU, but actually produces fewer tiles per hour than two processes. Our theory is that file I/O is maxed out—we’ve been using 250GB and 1TB internal IDE hard drives.
4. Turn off the option for indexing in your cache folder. In the Windows file manager, right-click on your cache folder and select Properties, then click Advanced (Windows XP), and uncheck the option “For fast searching, allow Indexing Service to index this folder”. This will make cache production 15-20% faster.
5. Check your available memory. During our caching processes, we’ve usually got the Windows Task Manager open because we want to know how much memory is being used by the ArcSOC.exe processes that are being used to create the cache. This is especially important if you’ve got other services running on the server, because these services are taking up memory, too, and you want to make sure the caching process, which will be more demanding of memory usage, is not pushing out of your available physical RAM and into your pagefile.sys (which will result in catastrophically slower caching times!)
6. Relocate the server’s pagefile.sys file. Unfortunately, stability of the caching process can be an issue, especially if you have other services running on your server. We’ve found one particularly good practice to minimize unexpected stoppage of our caching processes, which is to relocate the server’s pagefile.sys file onto a dedicated partition, preferably on a disk that is not primarily involved in caching. Minimally, we used to do this for printing large maps because it kept the pagefile.sys file from becoming fragmented, which limited the size of available memory blocks.
7. Avoid having other services running while you are caching – this is really a summarization of the last few tips together!

Recently, a new version of ColorBrewer called ColorBrewer 2.0 (colorbrewer2.org) was released by Axis Maps. ColorBrewer is a web tool for selecting colors for maps. The original ColorBrewer was released in 2002, and the update incorporates comments that the developers, Dr. Cynthia Brewer of Penn State University and Dr. Mark Harrower of University of Wisconsin Madison (he used to be a grad student at Penn State), have received over the years. Here are what some of the new features are:

• In the original version of ColorBrewer, you were given a set of predefined colors to modify the symbology of roads, cities and boundary lines. In the new version you can select from a wider variety of colors to customize the symbology of map features so they appear more similar to your own to see how a given color scheme works in conjunction with your symbology.

  

• You now have the ability to turn on a hillshade in the background. Transparency settings can be varied to see how the color schemes look when overlaid on a black to white ramp for the hillshade.

  

• Previously, you had to check the suitability of each color scheme individually for colorblind-safe, print-friendly or photocopy-friendly. You can now filter the color schemes based on those factors so only the ones that are suitable for your map’s media and display requirements are shown.

  

• The Export options allow you export colors into Adobe Illustrator or Photoshop, copy and paste color specifications, and/or download the color specifications into an Excel document.

  

• Also on the Export page is an option to download a tool to run ColorBrewer directly inside ArcGIS 9.X. This allows you to see the color schemes directly in ArcMap (instead of manually typing them in). The export page provides this link to the National Cancer Institute GIS where you can get more information on this tool as well as the download: http://gis.cancer.gov/tools/colortool/.

This doesn’t mean that the original version of ColorBrewer isn’t out there -- it still is!