Give Your Applications Mapping Capabilities, Part 1

Some of the most interesting features of modern web sites are based
on Geographical Information System (GIS) technologies. GIS techniques
essentially give you a way to manage and show geographical data in
your systems. For example, a manufacturing company can display a map
showing every building it occupies, every office in a building, or
the location of every sale it makes (worldwide), or a cab company can
use GIS data to track the position of its cabs nearly in real time.
Not too long ago, the expense and rarity of the maps themselves hindered
the use of GIS data in applications, but today, full-featured maps are
available through Google Maps, Google Earth, and Microsoft Virtual
Earth (among others) that you can use to display your GIS data in web
applications. The advent of such mapping systems is one of the most
exciting technologies to emerge in the last few years -- and they're
still undergoing constant and rapid evolution. Today, you can easily
collect geographical data, analyze and filter that data, and merge it
with a mapping provider to create maps that display the data to your
users. This article gives you a launch point by exploring what GIS data
is, how to collect it, and how to manage it. The first step in developing
a GIS business system is to collect the geographical data, a process
interchangeably called geomapping or geocoding. Both terms refer to
the process of retrieving the real-world position of the objects or
places you want to map. This process is simple for single-pointed
objects, either static or moving, such as a building, a car, an antenna --
objects you would show as a point on a map. But the process becomes more
difficult when you want to map lines and areas. Fortunately, the
technologies involved are basically the same; first you learn how to
work with points, and then you extend the process to work with lines
(pairs of points) and then areas (sequences of lines)... An example
Google Earth XML structure is written in an XML language called Keyhole
Markup Language (KML). The most important portion of the code is the
'Point' element, which defines a point using the 'coordinates' node;
the 'coordinates' node takes three comma-separated values that specify
longitude, latitude, and altitude... Getting started with GID
applications is quite simple: you collect points via GPS or existing
maps, and render them using a mapping application. You don't need
expensive hardware, and you can write simple software without too much
work. With a little effort, you can write exciting business applications
that feature 2D maps or 3D earth-rendering systems. More Information