Using The National Map Web Services in ArcMap

In this lesson, we will provide an overview
and demonstrate how to use The National Map’s

web services in a mapping application.

Although downloading data from The National
Map is a popular option for many users, there

are numerous situations where it may be preferable
to simply call The National Map web services

into your mapping application.

By using the National Map services, you can
eliminate data storage issues and the need

to download data on a regular basis in order
to maintain currentness.

By the end of this lesson, you will be able
to use The National Map web services in a

mapping application by adding The National
Map services as an ArcGIS Server REST service.

For this lesson, we will use Esri’s ArcGIS
software.

USGS has an Enterprise License Agreement with
Esri, and any USGS staff can request a software

license from the Enterprise GIS Team within
the Office of Enterprise Information.

There are a number of ways to call The National
Map’s services into ArcGIS.

We will demonstrate a quick way to set up
the usage of The National Map services in

ArcMap, so that the services are easily accessible
for repeated use.

This abbreviated list of services shows the
service URLs that we will add to ArcMap, in

order to access the
Base Map Services (http://basemap.nationalmap.gov/arcgis/services)

Vector Overlay Services (http://services.nationalmap.gov/arcgis/services)
Raster Overlay Services (http://raster.nationalmap.gov/arcgis/services)

Here you can see I’ve opened ArcMap.

Let’s start by clicking on the Catalog icon.

This is the icon that looks like a filing
cabinet.

In the Catalog pane which has now appeared,
locate the GIS Servers folder, and expand

the folder by clicking on the plus sign.

Select Add ArcGIS Server, and then double-click
it.

In the popup window that appears, select Use
GIS Services, then click Next.

Next, enter the Server URL for The National
Map Base Map Services, which we referenced

earlier (http://basemap.nationalmap.gov/arcgis/services)
Then click Finish.

You can see a new entry has been added in
Catalog for the Base Map Services.

Click on the plus sign to expand and view
the list of available layers.

To add one of these layers to your map, drag
and drop one of them from the Catalog pane

into the map pane.

Here, we will add the USGS Topo service to
the map.

Zooming in to an area of the map, we can see
that this is the same base map that appears

as the default cached background base map
in The National Map viewer.

Return to the Catalog pane, and add the Vector
Overlay Services, by following the same procedure.

Select Add ArcGIS Server, and double-click
it.

Select Use GIS Services and click Next.

Then enter the vector service URL, and click
Finish (http://services.nationalmap.gov/arcgis/services).

Expand the layer to see the available services.

Select a layer, then drag and drop it into
the map pane.

Here we are adding the map indices layer.

Likewise, also add the Raster Overlay Services
URL (http://raster.nationalmap.gov/arcgis/services).

Select a layer, then drag and drop it into
the pane.

Here we have added the 2011 Land Cover layer.

Looking at the list of services available
at each URL, you may notice what seems like

duplicative layers among them, and wonder
which is preferable for your use.

For example, you can see several different
NHD layers.

In general, the cached tile basemap services
provided at the basemap URL provide excellent

performance at scales from World to 1:18,000.

If you are mapping at larger scales, such
as those below 1:18,000, the vector and raster

overlay services are likely more preferable
to use.

A complete list of The National Map service
endpoints is available at the following site

(http://viewer.nationalmap.gov/example/services/serviceList.html).

And FAQs on the Services are available through
the Help link at The National Map viewer.

In this lesson, we discussed how to use The
National Map’s web services in ArcMap.

We added each of the three service URLs to
ArcMap using the Add GIS Services function

in Catalog, we expanded the services in Catalog
to see what layers are available, and demonstrated

how to drag and drop layers from Catalog into
the map pane.

The National Map web services provide a quick
and useful way to access the most current

National Map data for use in mapping applications,
without the inherent limitations of downloaded

data.

This concludes Lesson 5, to continue to the
next lesson, please return to the course homepage.