The National Map is a collection of mapping products and services
produced by the USGS National Geospatial Program.
The Products and Services are accessed via the Internet through
service calls and graphical user interfaces.
The National Geospatial Program has released a series of how-to videos
for people who are working with The National Map data and services.
The video show how to use the services and interfaces to access data
and tools for viewing, analyzing and printing geospatial data.
Lessons one and two serve as an introduction
to the training materials and the remaining how-to videos may be
viewed as needed in any order depending on the user.
Lesson 4a The National Map download application.
In this lesson, we will provide a brief introduction
on how to use The National Map download application.
To access The National Map
download application, go to apps.nationalmap.gov/downloader,
or from the TNM applications web page, apps.nationalmap.gov
locate and select the application titled TNM Download Client.
The TNM Download Application allows users to explore
and access the USGS staged products available for download.
This application is a user friendly version of the USGS
Staged Product Application Programing Interface,
and it is available on most platforms. Using TNM download
application is basically a two-stage process.
First, you will define your area of interest using a variety of map tools.
The second step is to select the products you are interested in.
Refer to Lesson 4b for instructions on how to download data and maps.
First, a little bit about
navigating the application interface and the map.
Let's start with the toolbar at the top of the screen.
A guide to the application is available by clicking the help link.
Access the guide by selecting a section below to expand
the content.
Custom
views are useful to regular users of the site.
They help narrow the interfaces, focus on specific themes
such as elevation, imagery or maps.
The share link button captures the URL at any point in the session
so that you can copy and share the information with someone else.
Please note that the application will show notifications on the top right
when a task is complete or if there is an error.
Now let's focus on the map interface.
You can zoom in and out with the plus and minus buttons,
or by using your mouse wheel and pan by holding the left
mouse button down and dragging the map to an area of interest.
The default map
view icon can be clicked to return the map to the initial extent
without removing your areas of interest, footprints
or thumbnails.
On the top right of the map screen
you can change the base map background.
You can also turn on the topographic map indices at any time for reference
by using the dropdown menu on the top right, below the base map dropdown.
Please note you may need to zoom in to see the map indices.
The search location box can be used to enter an address,
place name or map name to establish an area of interest.
The map zooms to the particular location.
There are several ways
to use the map to define an area of interest.
By default, the map extent geometry options are selected,
indicating whatever area is visible on the map
will be used for spatially filtering the product results.
In other words, you can use the pan and zoom to quickly narrow your search area.
A point or rectangle
can be drawn on the map to identify your area of interest,
using the extent, polygon, point,
or coordinates options.
To delete to polygon or point.
Click the clear geometry button.
You can also enter coordinates to create an area of interest.
Type the Xmax and Ymax in decimal degrees or lat long
for opposite corners of a box.
The area of interest can also be changed to no filter
to not restrict the products by any spatial filter.
This will produce a very large number of results.
This can be helpful if you are looking for data that covers the nation.
You can also select from a list of reference
polygons to establish an area of interest.
The reference polygon is now your area of interest for the search.
Lastly, a shape file can be
added to the application for visualization purposes.
A shape file can be used as a guide to draw your product
search area of interest by using the Polygon Draw Tool
or as an aid to choose selectable polygons.
The application does not use the shape filed to select an area, but provides
a visualization so that the user can create their own area of interest.
The shape file and its supporting files should be uploaded
into the application as a single zip file.
In this lesson, we demonstrated
the basic features of The National Map download application.
For the most up to date information on the national map
or the download application, please visit the delivery page at
usgs.gov/nationalmap/data
This concludes lesson 4a. To continue to the next lesson.
Please return to the course homepage.
usgs.gov/ngpvideos
refer to Lesson 4b for
instructions on how to download data and maps.