Tag: ArcGIS Online

About Using Explorer Screen Captures

We’ve recently had a few questions regarding the legal aspects of using ArcGIS Explorer screen shots in educational materials and publications. ArcGIS Explorer’s default content, and the content found on the Resource Center, are published via ArcGIS Online. The ArcGIS Online FAQs cover the use of this content.

In short, yes, you can use Explorer screen shots if you’re not using them for commercial purposes, provided you include the required attribution. When you choose View > Copy View to Clipboard, or use File > Print, you automatically capture the required attribution in the lower middle of the screen. 

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Taking a Look at Earthquakes (in many different ways)

This morning a 5.2 quake hit Illinois, shaking a large part of the Midwest, with many aftershocks following the main temblor. The quake was believed by USGS scientists to have involved the Wabash fault, an extension of the New Madrid fault. That fault generated the 1812 New Madrid quake, one of the largest ever recorded in the US.

So this morning we took at look at things using Explorer, first connecting to an ArcIMS service found on the Geography Network. We connected to the Geography Network at www.geographynetwork.com  and added the ESRI_Quake_Rec service to Explorer. That service is updated every 15 minutes by ESRI and the USGS.

We also added the USGS topo service (physical features layer) from the Explorer Resource Center (Contents > Layers) and here’s how things looked.

Next we visited the USGS Hazards Program site, and downloaded the CSV file for magnitude 1+ earthquakes over the last 7 days. We used Explorer’s import capabilities to create results from the lat/long coordinates to add them to our map. We chose the magnitude as the title, and date and time as the description. And below we’ve used the swipe tool on the topo layer to reveal the imagery underneath.

From the same site we also clicked to open the KML file.


Next, we imported the CSV file and created a file geodatabase. Why did we do that? You’ll find out in a couple of paragraphs, but here’s the local file geodatabase in Explorer. When we click on the earthquake location point, the attribute information for the quake is displayed.

Using the file geodatabase from above, we decided to be a little more creative. We buffered each point (to create polygons at each quake location for better visualization) then symbolized and extruded each of those polygons based on the earthquake magnitude using ArcGlobe. To make things more visually dramatic, we added a multiplier to the magnitude just to extrude the features further. We saved the ArcGlobe .3DD file, and published it via one of our ArcGIS Servers.

Here’s the area around southern California, and you can clearly see that during the past week this region has been seismically active too.

Finally, we tapped into the USGS “Shakemap” GeoRSS feed for a real time feed of live earthquake information.

Now we’ll have to be honest and let you know we’re cheating a bit with this one, but only just a little bit. The above screenshot showing a GeoRSS connection was created using today’s daily build of Explorer hot off the development machines.

For everyone else, you won’t be able to connect to a GeoRSS feed using the currently released Explorer 450, but you’ll be able to do everything else we’ve shown here. GeoRSS support is just one of the many new features we’ll be releasing with Explorer 480.

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Explorer at the FedUC

Last week marked ESRI’s Federal User Conference in Washington, D.C. During the plenary on Tuesday a variety of ESRI software and applications were showcased, including ArcGIS Explorer. We’ve had a few requests to recap what was shown in a little more detail, so here’s the overview of the ArcGIS Explorer plenary presentation.

First, the new Resource Center (introduced with Explorer 440) was highlighted by adding one of the newly published results – State Capitals – and showing the popup links to the USGS Science In Your Backyard Web site for each result. From there the Physical Features layer was added to the map, with a demonstration of the swipe and transparency tools. Shown below is the swipe tool being used with the seamless USGS topographic map layer that is included in the service.

The next part of the presentation showcased Explorer’s ability to connect to and integrate a wide variety of different content services, each published through different servers at locations throughout the US. The layers included:

  • several ArcGIS Online layers
  • an ArcIMS service from the ESRI Geography Network
  • a WMS services found via the FGDC clearinghouse
  • an ArcGIS Server map service (population growth by county)
  • a dynamic weather map service that updates every 15 minutes. The weather data is collected in an enterprise geodatabase (ArcSDE) via a connection to a Meterologix weather service, and published as an ArcGIS Server map service. The Explorer layer properties were set to update every 15 minutes to match the updates on the server.
  • an ArcGIS Server globe service (hurricane tracks)

Added to the map was a stamp of ”confidential.” This was done using the new Display Overlay property added to Explorer 440. Go to File, then Map Properties, and look for the Display Overlay property. The overlay can be placed at a variety of different locations, and is a great way to include your company logo with your map.

Next, Explorer’s ability to add a variety of local data sources was highlighted. Shown in the map below are a raster file (the historical map), a file geodatabase (Oregon county polygons), a shapefile (airport locations), and a KMZ file from the NRCS Web site (Snotel precipitation and snow levels). Also shown is the KML/Z popup window.

The airport symbol is part of Explorer’s new billboarded point symbol set. These are optimized for performance, so even though there are many 10s of thousands of airports worldwide (see below) the navigation speed is not impacted significantly.

The city of Portland was visited next, with a 3D cityscape of the downtown area. The buildings were authored using ArcGlobe, extruding building footprints based on attributes containing elevation. Also shown are tax lots (an ArcGIS Server map service) and a link to a YouTube video showing a walking tour through Portland.


Several tasks were demonstrated, including a few of the default tasks (powered by ArcGIS Online) and a Weather Finder task downloaded from the Explorer Resource Center. Finally, a custom service area analysis task was used to determine drive time service areas, shown below as a red polygon. The geoprocessing task was authored using ArcGIS Desktop, and published via ArcGIS Server.


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ArcGIS Explorer = Many Kinds of Layers

One of Explorer’s distinguishing features is its ability to connect directly to a wide variety of Web service-based content and a wide variety of local data, both vector and raster, and integrate and manipulate them all in a single map. It’s truly in a league of its own in this regard. Shown below is Explorer with:

  • 2 ArcGIS Online layers
  • 1 WMS layer
  • 1 ArcIMS layer
  • 2 2D ArcGIS Server layers (1 of them dynamically updated every 10 minutes)
  • 1 3D ArcGIS Server layer
  • 1 KML (from the USGS site)
  • 1 KMZ (from the NOAA site)
  • 1 Shapefile
  • 1 Result (a collection of points imported from GPS coordinates in a textfile)
  • 1 BSQ raster image (from the EROS Data Center)

And we could add even more.

Several of the layers have been made partially transparent so they can be overlayed, and several have scale dependencies. The underlying data sources for the Web-based content include everything from enterprise ArcSDE geodatabases, file and workgroup geodatabases, and local sources that include shapefiles, rasters, and points added from textfiles containing GPS coordinates.

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Updates to ArcGIS Explorer's Services = Cache Cleaning Time

Just prior to this latest release a couple of the ArcGIS Online services which deliver content in several of the maps and layers available through the Contents tab on the Explorer Resource Center were updated. These changes include the following:

  • World Shaded Relief: added additional levels of detail
  • Physical World: added additional levels of detail, plus bathymetry at small scales

An ArcGIS Online Forum post also covers these changes, with a few additional details.

To view these updates, you’ll have to clear your cache for these layers. To do so, choose Tools, Manage Layers, and then select the layers above (if you are using them in your map) and click the Clear Layer Cache button.

If you don’t use these layers regularly, but want to make sure you’ve cleared their cache to see the updates, you can take your cache housekeeping a little further and delete all of your cache, and start afresh. This isn’t required, but you might want to do this from time to time just as a regular housekeeping task.

Remember that if you do clear all your cache, you’ll be fetching fresh cache from ESRI’s servers, as well as from any other servers that you may connect to, and generating new cache for your local data sources. Your performance will be a little slower while you fetch or generate cache again.

To clear out your cache, choose Tools, then Options, and choose Cache in the options list. Click Dick Cache, and under Cache Clean Up choose All Caches before clicking the Delete Caches button.

See the Help topic Cache Management in ArcGIS Explorer for additional details, and more information.

There will be other service updates during Q1 next year, and we’ll keep you posted as to when they’ll be happening.

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Designing a map to overlay ArcGIS Online in a Web application

In November 2006, ESRI announced the public beta release of ArcGIS Online, a set of base map and reference services available for ArcGIS users. These services include imagery, street maps, elevation data, and more. For ArcGIS Desktop users, overlaying your own data on top of ArcGIS Online is as easy as clicking the Add Data button.

But how do ArcGIS Server users overlay their data with ArcGIS Online in a Web application? It’s straightforward to add multiple services to a Web application in Manager or Visual Studio. Remember, though, that ArcGIS Online services are cached, so when using them with your map services, you’ll need to make considerations on how your map services are prepared and cached.

In this post, we’ll talk about some of the steps required for building a cached map service that you can overlay with ArcGIS Online. Note that Version 9.2, Service Pack 2 of the Web ADF included enhancements for overlaying multiple cached maps in a Web application, so before attempting these steps, you’ll need to get Service Pack 2 or greater.

Overlaying map caches in the Web ADF is all about choice of scales. For best performance, the scales from all of your map caches should match so that the original tiles can be used for each layer. Suppose you’re overlaying Cache A, which has 14 scales, with cache B, which covers a smaller area. You don’t have to build Cache B at all 14 scales, but you should make sure that the scales you do use for Cache B match a sequential subset of the scales used in Cache A.

What scales are used in ArcGIS Online?

The ArcGIS Online caches use a set of precise scales that have been carefully devised for two purposes:

  • Match the scale-change thresholds built into ESRI globe clients The globe caches on ArcGIS Online were originally made from the 2D caches draped over the globe (To learn how you can use this technique, see the previous post Creating a 3D globe cache from a 2D map cache.). Unlike 2D caches for which you can pick your scales, ESRI 3D clients have built-in levels at which globe cache tiles take effect. If you use the scales in ArcGIS Online for your 2D caches, you can depend on your original rendering for each scale level appearing in ArcGIS Explorer and ArcGlobe if you ever use your service to create a 3D cache.
  • Match edges at 180 degrees longitude when used on a globe Because the 2D caches are used to make the 3D caches, the scale levels used must be engineered to avoid overlap at the “edge” of the globe at 180 degrees longitude.

The scales (or technically, “scale factors”) used by ArcGIS Online are as follows:

  • 147748799.285417
  • 73874399.6427087
  • 36937199.8213544
  • 18468599.9106772
  • 9234299.95533859
  • 4617149.97766929
  • 2308574.98883465
  • 1154287.49441732
  • 577143.747208662
  • 288571.873604331
  • 144285.936802165
  • 72142.9684010827
  • 36071.4842005414
  • 18035.7421002707
  • 9017.87105013534
  • 4508.93552506767

Remember, you only need to use these precise values when building the cache in ArcGIS Server. When designing your map in ArcMap, you can use these scales without worrying about the values beyond the decimal point. To learn how to load this list of scales into ArcMap’s dropdown list, see the post Viewing cached map services (such as ArcGIS Online) in ArcMap.

Designing your map

How did ESRI design the maps that are available in ArcGIS Online, for example, the World Street Map? The cartographers in charge of this project first determined the scales at which the map would be cached, then chose layers and symbology appropriate for each of those scales. You’ll do a similar thing when building your map service that will overlay ArcGIS Online.

This is an easier process when working with raster imagery. You’ll notice that the ArcGIS Online satellite and aerial imagery services only include two or three different resolution raster images, and no extra symbology changes are needed before caching these at numerous scale levels. However, when using vector features, you may need to make subtle symbology changes at each scale in order to keep your layers from cluttering the map, or to keep the map from looking too sparse. Since you’re more likely to be putting your vector data on top of ArcGIS Online raster layers, instead of vice versa, we’ll focus on what it takes to prepare vector data for caching and overlay.

Here’s a suggested workflow for preparing vector layers for a map service that will overlay ArcGIS Online:

  1. First, do some planning by making a list all of the layers that will be visible in your map. Include all layers, whether they will be visible at all scales or not. Leave some space in between each layer name.

  2. For each layer, list the ArcGIS Online scales at which the layer will be visible. For example:


    Fire stations


  3. Create a new map document and set the data frame coordinate system to GCS_WGS_84. Currently, you must use this coordinate system for any map that you intend to overlay with ArcGIS Online. In the future, ArcGIS Online intends to provide maps in additional coordinate systems.

  4. Add each layer to your map n number of times, n being the number of scale levels at which the layer will be visible. (You may find that copying and pasting the layers back into the table of contents is faster than using the Add Data button for this purpose.) You can keep the default symbology of all layers for now.

  5. In the table of contents, give each instance of the layer the name of one of the scales you chose and set a scale range on the layer that encompasses that scale. For example, name one of the layers Parks 1:72k and set a scale range of 1:50,000 to 1:100,000. Name another layer Parks 1:144k and set a scale range of 1:100,000 to 1:200,000. Be sure that the scale dependency thresholds you choose do not overlap the next highest or lowest ArcGIS Online scale (for example, you would probably not want to set a scale range of 1:100,000 to 1:300,000 because that encompasses two ArcGIS Online scales: 288571.873604331 and 144285.936802165).

  6. Now create a group layer that includes all scales for a layer. For example, take the layers Parks 1:72k, Parks 1:144k, Parks 1:288k, and Parks 1:577k and make a group layer out of those called Parks. The image below shows an ArcGIS Online source map document that has been organized in a similar way for roads and place names. Note the group layers in the table of contents.

    Group layers in an ArcGIS Online source map document table of contents

  7. Set the appropriate symbologies for all layers at all scales. A good strategy is to start at the smallest (farthest out) scale, set symbology for all layers, and then work inward by scale level, setting the symbology for all layers at that level before moving in to the next scale. This is where loading the custom scales into the ArcMap dropdown, as mentioned earlier, can be useful.

  8. When you are satisfied with the appearance of your map document at all scales, publish it as an ArcGIS Server map service.

  9. Create the map cache, using all or a sequential subset of the precise ArcGIS Online scales specified above. For the tile origin, use -180, 90. For the tile size, use 512 X 512. For image format, it’s recommended that you use PNG8. You should not use JPG if you will put the cache on top of any other layer, since JPG does not support transparency. Also, if you choose PNG24, Internet Explorer 6 users may not be able to see the transparency correctly due to a limitation in the browser.

    An example of the cache generation tool containing a subset of ArcGIS Online scales

    Additional help for creating the cache:

  10. Add the cached map service and an ArcGIS Online service to a Web Mapping Application.

    Note: Manager gives an option for you to select which service will provide the coordinate system and extent for the map. In this scenario, you can choose either the ArcGIS Online service, or the one you just cached, depending on the initial extent you want. Do not select any other services that your map may contain.


Here’s an example of a map that overlays ArcGIS Online. In this example, I created a map of USGS topographic map boundaries and names that is designed to overlay the NGS_Topo_US_2D service from ArcGIS Online. The boundaries are for three available series of USGS maps, including the 7.5 minute quadrangles. You’ll need to zoom in from the initial extent in order to see the boundaries.

Topographic map boundary viewer

The boundaries map is cached at the following scale levels:

  • 4617149.97766929
  • 2308574.98883465
  • 1154287.49441732
  • 577143.747208662
  • 288571.873604331
  • 144285.936802165

Notice how the symbology of the boxes and the annotation changes as you zoom between scale levels. This example requires some flexibility with the procedure listed above because some of the layers use the same symbology for multiple scale levels. Also, some of the layers are designed to overlap at certain scales. For example, the solid dark lines overlay the dashed green lines at a few scales.

It’s possible that your map projects will require similar adjustments. Detailed planning using drawings, tables, and other visual aids, if necessary, can help you set the proper scale dependencies and symbology for each layer. Careful testing, as well as some trial and error, will also help you ensure that your map looks appropriate at all scales. It’s worth the extra effort to make sure the map is correct before creating the cache, especially if the cache will include many scale levels.

-Sterling Quinn

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Connecting to ArcGIS Online to Use Individual Services

Recently we’ve had a few questions on how to access individual ArcGIS Online services with Explorer. So we thought we’d review how you can do that, and provide you the connection information here. Starting with the next release of Explorer you will no longer need to follow these steps, but in the meanwhile, here’s how to access them.

First, pre-published maps for Explorer can be opened directly from the ArcGIS Explorer Resource Center. The Resource Center can be opened by choosing Help > ArcGIS Explorer Resource Center.

When you click to open one of these maps it will replace your current map (just like opening a new map document in ArcGIS Desktop).

These pre-published Explorer maps are composed of a variety of separate ArcGIS Online services. Rather than open a completely new map, you can add these services individually to your current Explorer map. 

To access the individual ArcGIS Online services you need to create a new ArcGIS Server connection using the Add Content dialog in Explorer. To create the connection, use the following:

URL: http://services.arcgisonline.com/v92
User Name: arcgis_beta
Password: beta

Check the box to remember the user name and password so you won’t be prompted for these in the future. Once the connection is established you will see a list of all available ArcGIS Online services grouped into several different folders. Just click to add any of them to your map.



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How to build a cache with the same tile sizes and scales as ArcGIS Online

When building a map cache that will overlay ArcGIS Online in a .NET Web mapping
application, you need to match the tile sizes and tiling origin to that used by
ArcGIS Online. You also should make an effort to match as many scale levels as
practical with the ArcGIS Online scale levels. To quickly load this information
into the cache generation tool, you can use this
cache configuration file for ArcGIS Online

The illustration below shows how you can use the configuration file when
generating a map cache.

Browse to the tiling scheme and the scales will fill in automatically 

The closest scale level available in ArcGIS Online is about 1:4,500. If the area
you are caching is very large, this and some of the other close scale levels
may not be practical for caching. You can remove the scale levels by manually
editing the cache configuration file in an XML editor. Each scale level has an
LODInfo tag. Remove the entire tag to remove the scale level, as shown in the
example below:

Remove the LODInfo tag for each scale you want to delete 


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Explorer Workshop at GeoWeb 2007

Monday, July 23, at the GeoWeb 20007 Conference in Vancouver, British Columbia, a workshop featuring ArcGIS Explorer and ArcGIS Online will be offered. The workshop is titled Unlocking the Potential of ArcGIS Explorer and ArcGIS Online.

 The half-day workshop will focus on Explorer and will cover a broad range of topics, including initial installation and setting up your preferences, to authoring your own tasks and centralized enterprise administration. ArcGIS Online will also be featured, including different ways you can use it in your ArcGIS Desktop. Whether an expert or novice, the course will have something for everyone. If you’re already planning to attend, we hope to see you there. Registration can also be made on-site at the conference, and single day and single workshop passes are available.

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Introduction to ArcGIS Online Live Training Seminar

Here’s something that may be of interest to ArcGIS Explorer users. Tomorrow, Thursday, July 19, ESRI will present a Live Training Seminar titled Introduction to ArcGIS Online.

The seminar will be a live broadcast covering all of the basics of using ArcGIS Online in ArcMap and Explorer. The seminar will be given three times throughout the day, so there’s lot’s of opportunities to tune in. Listeners will also have a chance to ask questions. If you’ve not watched a live training seminar before, they’re a great way to learn more about a particular topic.

Click here for the broadcast schedule, software requirements for joining the seminar, course details, and other information on the Live Training Seminar series.

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