This document discusses different methods for forecasting airport passenger traffic: seasonally adjusted and seasonally fitted. Seasonally adjusted data removes seasonal fluctuations to simplify interpretation, while seasonally fitted defines a model controlling displacement and rotation factors to accurately map trends over 1-3 years. Both methods are useful, with seasonally adjusted best for overall trends and seasonally fitted ensuring the right picture over shorter periods. Sample forecasts are provided for several major international airports using the seasonally fitted method.

1. AIRPORTS Forecasting
Getting The Right Picture
Head to Head analysis
Seasonally Adjusted Vs Seasonally Fitted
by: Mohammed Salem Awad
Research Scholar – Aviation Management
Furthers to my previous articles, this article will address the
difference and compare the Seasonally Adjusted technique Vs
Seasonally Fitted. Basically Forecasting model can be defined by
four components i.e Trend, Cyclical, Seasonal, and Irregular.
A model that treats the time series values as a sum of the
components is called an additive component model
(Yt=Tt+Ct+St+It) , While a model that treats the time series values
“Facts are Many but
as a product of the components is called a multiplicative
the Truth is One.”
component model (Yt=Tt×Ct×St×It) Rabindranath Tagore
Seasonally Adjusted:
Most economic series published by
international Organizations ( IATA, ICAO) are
seasonally adjusted because seasonal variation
is not of primary interest. Rather, it is the
general patterned of economic activity,
independent of normal seasonal fluctuation that
is of interest. So seasonally adjusted is done to
simplify data so that they may be more easily
interpreted by statistically unsophisticated users
without a significant loss of information. e.g –
IATA Forecasting.
Seasonally Fitted:
General guidance, we set a constrains to
measure the Goodness of Fit, this time we use
R and Signal Tracking ( R ≥ 80 and 4 ≥ S.T.≥ -
4 ). The seasonal model fairly fitted by defining
and controlling two main factors for mapping
the figure, first is Displacement Factor which
can be defined by the value of signal tracking, it
is either upper or lower of the base forecasting
line. Where the second factor is the rotating
angle and that can be monitor by the value of R
i.e why both R and signal tracking are displayed
in the graph.
Summary:
Both methods are fair, so to get the general
trend, we use seasonally adjusted but to ensure
to get the right picture we have to define the
seasonality patterned and define their accuracy
measuring factors in terms of R and Signal
Tracking, the issue of this method only its
applicability for short range period 1-3 years if
we exceed the time/period the program should modified and set a new one.

2. AIRPORTS Forecasting INTERNATIONALS Airports
A'A Airport
Airports Forecasting:
Airport forecasting is an important issue in
Aviation industry. It becomes an integral parts of
transportation planning. It sets targets and goals
for the airports, either for long term or medium
term planning. The primary statistical methods
used in airport aviation activity forecasting are
market share approach, econometric modeling,
and time series modeling.
Model Used:
Based on a historical data of the airports, (3 years
on monthly bases) the mathematical model is
developed where its fairness and goodness of fit
can be defined by two important factors:
R2 (Coeff. Of Determination) > 80%
S. T (Signal Tracking) ..(- 4  S.T.  4)
This time we try to set (S.T.) to Zero
Oslo Airport, Gardermoen (Norwegian: Oslo
lufthavn, Gardermoen; IATA: OSL, ICAO:
ENGM), also known as Gardermoen Airport, is
the principal airport serving Oslo, the capital of
and most populous city in Norway. Oslo is also
served by the low-cost Torp Airport and Rygge
Airport. Gardermoen acts as the main domestic
hub and international airport for Norway, and is
the second-busiest airport in the Nordic countries.
R2 = 93 % , S.T.= 0
2013(F) = 23,717,975 Pax
Munich Airport (IATA: MUC, ICAO: EDDM)
(German: Flughafen München), is an
international airport located 28.5 km (17.7 mi)
northeast of Munich, Germany, and is a hub for
Lufthansa and Star Alliance partner airlines. It is
located near the old city of Freising and is named
in memory of the former Bavarian Prime minister
Franz Josef Strauss. The airport is located on the
territory of four different municipalities:
Oberding (location of the terminals; district of
Erding), Hallbergmoos, Freising and Marzling
(district of Freising).
R2 = 94 % , S.T.= 0
2013(F) = 42,565,394 Pax
Paris Orly Airport (French: Aéroport de Paris-
Orly) (IATA: ORY, ICAO: LFPO) is an
international airport located partially in Orly and
partially in Villeneuve-le-Roi, 7 NM (13 km; 8.1
mi) south of Paris, France. It has flights to cities
in Europe, the Middle East, Africa, the
Caribbean, North America and Southeast Asia.
Prior to the construction of Charles de Gaulle
Airport, Orly was the main airport of Paris.
R2 = 91 % , S.T.= 0
2013(F) = 29,120,442 Pax

3. AIRPORTS Forecasting INTERNATIONALS Airports
Edinburgh Airport (Scottish Gaelic: Port-
adhair Dhùn Èideann) (IATA: EDI, ICAO:
EGPH) is located at Turnhouse in the City of
Edinburgh, Scotland, and was the busiest airport
in Scotland in 2011, handling just under 9.4
million passengers in that year. It was also the
sixth busiest airport in the UK by passengers and
the fifth busiest by aircraft movements. It is
located 5 nautical miles (9.3 km; 5.8 mi) west of
the city centre and is situated just off the M8
motorway.
R2 = 93 %
S.T.= 0
2013(F) = 9,688,572 Pax
Avinor – (airports traffic) AS is a state-owned
s limited company that operates most of the civil
airports in Norway. The Norwegian state, via the
Norwegian Ministry of Transport and
Communications, controls 100 percent of the
share capital. Avinor was created on 1 January
2003, by the privatization of the Norwegian Civil
Aviation Administration known as
Luftfartsverket. Its head office is in Bjørvika,
Oslo, located on the seaside of Oslo Central
Station
R2 = 92 %
S.T.= 0
2013(F) = 49,847,034 Pax
Gold Coast Airport, or Coolangatta Airport,
(IATA: OOL, ICAO: YBCG) is an Australian
domestic and international airport at the southern
end of the Gold Coast, some 100 km (62 mi)
south of Brisbane and 25 km (16 mi) south of
Surfers Paradise. The entrance to the airport is
situated in the suburb of Bilinga on the Gold
Coast. The runway itself straddles five suburbs of
twin cities across the state border of Queensland
and New South Wales. During summer these
states are in two different time zones.
R2 = 0.64 %
S.T.= 0
2013(F) = 5,551,812 Pax

4. AIRPORTS Forecasting INTERNATIONALS Airports
Brisbane Airport (IATA: BNE, ICAO: YBBN)
is the sole passenger airport serving Brisbane and
is the third busiest airport in Australia after
Sydney Airport and Melbourne Airport. Brisbane
Airport has won many awards. Brisbane is
currently served with 46 domestic destinations in
all States and Territories and 32 international
destinations. For the 12 months ending May 2011
total passengers were 20,056,416.
R2 = 93 %
S.T.= 0
2013(F) = 21,932,169 Pax
Cairns Airport (IATA: CNS, ICAO: YBCS) is
an international airport in Cairns, Queensland,
Australia. Formerly operated by the Cairns Port
Authority, the airport was sold by the Queensland
Government in December 2008 to a private
consortium. It is the seventh busiest airport in
Australia. The airport is located 2.3 nautical miles
(4.3 km; 2.6 mi) north northwest[1] of Cairns or 7
kilometres (4.3 mi) north of the Cairns central
business district, in the suburb of Aeroglen. The
airport lies between Mount Whitfield to the west
and Trinity Bay to the east.
R2 = 92 %
S.T.= 0
2013(F) = 4,297,288 Pax
Melbourne Airport (IATA: MEL, ICAO:
YMML), also known as Tullamarine Airport, is
the primary airport serving the city of Melbourne,
and the second busiest airport in Australia. It was
opened in 1970 to replace the nearby Essendon
Airport. Melbourne Airport is the sole
international airport of the four airports serving
the Melbourne metropolitan area.
The airport is 23 km (14 mi) from the city centre.
The airport has its own postcode—Melbourne
Airport, Victoria (postcode 3045). This is
adjacent to the suburb of Tullamarine.
R2 = 83 %
S.T.= 0
2013(F) = 29,942,351 Pax
Reference:
http://en.wikipedia.org/wiki/Main_Page