What is online mapping?
There are many definitions for online mapping.
Online mapping is the process of creating and publishing a map
online that allows a user to interact with the map content.
Online mapping is not simply posting a static map in an image format (e.g., JPG, PDF) to a web site.
Online mapping provides dynamic maps that change based on a user's requests,
such as zooming in and out, panning or moving the map, and identifying features on the map.
The information reported back to the user is usually extracted
directly from a database. For example, a user may want to know more about a
building feature on the map. When the user clicks on that building, information such as the name
of the building, the year it was built, and the building's use might be the
information attributes that are returned.
Uses of online maps
Online mapping is used to disseminate information to the general public and to provide support systems for decision-makers. Since a user only needs a web browser, online mapping applications are an ideal way to provide GIS results to people having little or no GIS training. The web site developer determines how simple or complex the mapping site will be and what the user will see.
The most common type of online mapping application lets users find locations
and get driving directions. Popular examples of these location-based services are MapQuest,
Google Maps, and Yahoo! Maps. AAA online maps allow users to create a trip map with driving directions,
pictures of tourist destinations, and maps of lodging and restauraunt locations. Local and
federal government agencies, as well as scientific institutions and data production companies
use online mapping to distribute data, such as local streets or satellite images.
Online mapping is also very popular for social networking, such as posting
photos or creating blogs attached to specific locations throughout the world.
Online mapping possibilities exposed
Newer online mapping applications are including more of the funtionality previously found in traditional GIS systems.
For example, you could create an online mapping site that displays locations of weather stations where
users can click a button to display a continuous field of temperature or precipitation.
Alternatively, a map developer could display elevation data where users can click a button
to display 3D hillshades and viewsheds. With the use of programming languages and
advanced web technologies, online mapping offers a world of possiblities.
How does it work?
Typically, online mapping site users start by viewing a map on a web site. As the
user moves around the map, the web browser sends a request to a server that generates a revised map image and sends that
image to a web server and then, back to the web browser. These servers are typically called Internet Map
Servers (IMS). Companies and agencies (Google, ESRI, Microsoft, NASA, USGS) run mapping servers
that are publicly accessible. Universities and individual researchers also own map servers to
distribute imagery and data. Your online mapping web site can easily incorporate the image and
data feeds from others' IMS sites.
In either case, you can create online mapping sites that consume maps and data from one
or more of these Internet Map Servers.
The best way to understand online mapping is to start using an online mapping site. We have provided a brief list of sites under the Web Sites tab that illustrate varying levels of complexity. Take a look! If you've never used an online mapping site before, you'll be amazed at what is possible!