WHAT CAN GIS DO FOR AIRPORTS?
The Air India flight, AI171, took off from Ahmedabad’s Sardar Vallabhbhai Patel International Airport in India’s western state of Gujarat. The Boeing 787-8 Dreamliner was headed to London Gatwick, and scheduled to land at 6:25 p.m. local time (1:25 p.m. ET). Air India said 242 passengers and crew members were on board
The personality of each authority that manages an airport is as different as the surrounding communities and governing
bodies. The reasons that airports desire a GIS are also
varied. The impetus for development of a GIS may
come from an individual engineer or planner, it may
come about from difficulty in understanding a specific
problem, it may come from the surrounding communities or from the municipal government, it may come
from an opportunity for an application which presents
itself, and it may even result from a conscious management decision.
Management of airports is a very dynamic and very
exciting profession. If one looks at the changes that
have occurred in aviation and airports in the last 20
years, what is constant is that change is always
occurring. New aircraft, new regulations, new
technology, new procedures, and new construction are
all part of the job. Computer management tools are
often highly effective for managing anything that is
always in a state of change. GIS is one such computer
management tool that has great potential for the
management of an airport. Although GIS is an
excellent management tool, it is also an excellent
analysis tool for engineers and planners. Moreover, this
tool is an information system; it could even become the
airport information system. A GIS can be as small or
as large and all-encompassing as is desired.
The reasons that a GIS is needed and wanted at airports vary greatly, and the following chapters will give
some specific applications. Some of these applications
are a result of the management capabilities of a GIS:
pavement management, infrastructure management,
management of lease space, management of noise mitigation programs or management of projects. Some of
the applications are a result of the ·analytical capabilities of a GIS: noise analysis, noise monitoring, and
pavement analysis. One of the reasons that airports
need GIS is to integrate data from several sources and
display it. Funding is a major limitation at airports, as the FAA
monitors and approves most major projects under development. Most of the potential applications of GIS
at airports will qualify for federal funding either under
the airport improvement program, planning grants or
under the voluntary Part 150 program. The real key is
to develop the GIS under the application that is eligible
for funding and to add additional applications later as
time and resources permit for cost-effectiveness.
The major cost of developing a GIS is not the hardware or software required. The major cost by far is the
development of the graphic and attribute data. If a GIS
is going to be developed for noise mitigation, most of
the airfield pavements must be included in the graphic
data representing the airfield anyway. If the graphic
data representing the airfield are included in such a
way that a pavement management system can be supported with the same GIS using a different attribute database, the cost of developing the application has been
reduced considerably.
If an airport is large enough to invest in a management system of some kind, the airport is probably large
enough to have a GIS. Even small airports have to
prepare master plans, airport layout plans, and other
federally mandated requirements such as a storm water pollution prevention plans. Since these requirements
must be completed anyway, it will eventually save
money if they can be computerized in CAD drawings.
Once CAD drawings are completed, an entry-level GIS
can be started on a personal computer.
By prior planning for future GIS applications, both
in the airport’s data management plan and in the development of a GIS application that is funded, future
GIS applications can be added at reduced cost with a
better chance for becoming cost-effective. The ultimate
power and usefulness of a GIS is not measured by its
ability to perform an intended single application; the
real power comes when it can be used as a tool to
quickly analyze a critical problem which was not even
contemplated when the system was actually designed.
DISTINCTION BETWEEN GIS AND
OTHER INFORMATION SYSTEMS
systems is not that a GIS uses geographically referenced or spatial data. Other systems also use geographic information such as automated mapping (AM),
computer cartography, and land information systems
(LIS). There is an entire industry of professionals that
caters to those specific applications. The real distinction between GIS and other systems is the ability of a
GIS to perform spatial analysis.
Spatial analysis is the ability to analyze the spatial
relationships of objects to each other. For example, to
determine which homes in a specific district are within
500 feet of an overhead power line, requires knowing
the locations both of the power lines and of the homes
and performing the spatial analysis to determine if the
500 foot horizontal distance criterion is met. It is this
spatial analysis capability of a GIS, coupled with the
tremendous ability to integrate data and visually display it, that has caused the great popularity of GIS for
a multitude of professions.
Often confused with GIS is computer-aided drafting
or computer-aided design (CAD). There have been
many improvements in the state-of-the-art of CAD in
the last several years. With CAD packages now available on personal computers, it is possible to have geographically referenced drawings. It is also possible,
with what has been termed as “SmartCAD,” to attach
information in a relational database to an object in a
CAD drawing. This process is similar enough to be
confused with GIS, especially since some GIS packages are using CAD programs for the editing of the
graphic data. However, the distinction between a true
GIS and SmartCAD is that only a GIS can perform
spatial analysis using the graphic and attribute data.
Another reason for the confusion concerning what is
a GIS is that some software vendors are representing
their products as GIS when not all the capability of
performing spatial analysis is actually there. Some
products can do little more than graphically display
data. Other products are severely limited in their spatial analysis capabilities. Another factor adding to the
confusion is that some of the intrinsic capabilities or
advantages of GIS can be achieved without the spatial
analysis component. In the following chapters several
potential applications of GIS will be presented, but not
all the applications will require the spatial analysis
capability of a GIS.
For example, some of the infrastructure management
applications can be performed by specialty software
programs designed for automated mapping or facility management (AM/FM). However, a GIS can perform
the automated mapping function, but AM/FM software
cannot perform the spatial analysis capabilities of a
GIS. GIS is an engineering tool with capabilities that
may not be immediately recognized as needed; but
once the capabilities are recognized, new applications
and analyses can be performed.
INTRINSIC GIS CAPABILITIES
Having defined what a GIS is and is not, the next
step is to define some of intrinsic capabilities of a computerized GIS. One of the primary reasons that GISs
are developed is to visually see the spatial relationship
of data. An intrinsic capability of all GIS is the ability to graphically display and compare raw or queried
data. The old adage is that a picture is worth a thousand words. Data becomes information only after a relationship can be visualized between the raw data and
something else.
Data visualization is a major selling point for GIS
because far more information can be conveyed much
faster by graphically visualizing the relationships of
either raw data or queried data. If someone were trying to justify a pavement rehabilitation project in a
certain area, he/she would be better able to convince
the decision makers with a graphical representation of
the relative severity of distress levels of each geographically located pavement than by providing a multiple page, computer generated, tabular report.
Another capability that is viewed as a definite advantage is the ability of GIS to integrate multiple databases. An important point about GIS is that the attribute databases need not reside on the desktop where
the analyses are performed. It is completely feasible to
-graphically display the results of a query on one remote
database with the results of another query from a second database. This is an important aspect of GIS and
is used frequently. One advantage this provides is that
several users with access privileges can analyze data
that belong to another system, but the individual
doesn’t have to duplicate the data or have the responsibility of keeping the other person’s data up to date.
Another advantage, not normally considered when
purchasing or developing a GIS, that is quickly realized after using GIS: it provides an effective mechanism for detecting errors in the database. If the graphic
features are linked to the attribute database and queries are made, it is obvious if a section is missing or
displays an unusual value. These errors are far more often present in large databases than one would think.
Any large database with manually entered data is
highly susceptible to errors.
