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Geographic
Information Systems (GIS)
GIS is a simplified
world, brought into a computer environment.
It
could be compared with cartography, but GIS adds another
dimension - data. A map may display a parcel
of land in green, with a label "Park". The park is made up
of two dimensional boundary lines and a label.
In
a computer,
the boundary data can be stored in a table or database,
and the word "park" can be stored in another table, and linked
to
the
boundary information. Now you can ask the computer a simple
question, like "how many parks are there withing 10km radius
of this point?". The tabulated data easily finds the answer
and displays it, either in tabular form, or in map form.
This is GIS.
GIS can model what-if and thematic scenarios,
using date/time, distance or any other
criteria. Applications include
envronment, health, roads, utlities, town planning,
property records, demographics and marketing. The digital
map database
interacts with tabulated data on each entity, so is completely
relational.
(With acknowledgement to Tor Bernhardsen,
Geographic Information Systems, An Introduction, publ 1999,
John Wiley and Sons) |
Getting
information into GIS
Information
stored in GIS is retrieved in many ways.
Information can be scanned from old maps
or plans to start the process. Then information relating
to the various subjects required, can be entered as supporting
data.
At Johnny Appleseed GPS, we have expertise
to supply and support the field methods for
obtaining
and
verifying
data.
Programs are available for computer and
hand-held devices, to capture position and other information
in a systematic
format. This information is formatted in the same manner
as the parent GIS, for which the data is intended.
We supply field compatible hardware (camera,
PDA, GPS, DGPS) and software to capture data.
Please see links below. |
Johnny Appleseed GPS
