Figure 15: Cleaning of kinks for slower flights.
. Adjustment of flight level
The method used consists of:
o
Dropping a flight leg if the slope in absolute value between two points is higher than 10000 ft.
o
Averaging the flight leg if the slope in absolute value is higher than 3000 ft but less than 10000ft. The absolute value of the slope of the previous leg is extended to the erroneous point but the sign of the flight leg slope is kept (Figure 16). This allows keeping the position of the point in terms of latitude and longitude but to smoothen the trajectory for compensating the erroneous flight level.
trajectories did not include flight level or presented inconsistent ground speeds due to successive positions recorded in a short period by different radar centres and rounded to the closest minute.
Table 28: Code system attributed to the zone indicator combinations.
Departure En route Arrival Code
C F C 0
C F I 1
C D C 2
C D I 3
I F C 4
I F I 5
I D C 6
I D I 7
. Creation of a table with necessary information for the merge.
The assessment finished; the information contained into the temporary flight table and the first and last legs information from the temporary flight leg table is imported into a temporary merge table (Table 29).
Table 29: Table MERGE_FLIGHT_INFO_TEMP.
Col # Column Name Data Type Data Description
1 OID NUMBER(15) Object Identifier for the flight
2 CALLSIGN VARCHAR2(15) Flight’s callsign
3 FLUID VARCHAR2(21) Flight unique identifier
4 DEP_AIRPORT VARCHAR2(5) Airport of departure
5 DEP_TIME DATE Time and date of departure
6 ARR_TIME DATE Time and date of arrival
7 FIRST_EVT DATE Time of the first event recorded
8 FIRST_LAT NUMBER(17,7) Latitude of the first event
9 FIRST_LON NUMBER(17,7) Longitude of the first event
10 LAST_EVT DATE Time of the last event recorded
11 LAST_LAT NUMBER(17,7) Latitude of the last event
12 LAST_LON NUMBER(17,7) Longitude of the last event
13 ASSESSMENT NUMBER(1) Number (0 to 7) attributed to the trajectory for assessing the quality
14 MATCH_OID NUMBER(15) Object identifier used to match flights that must be merged
16 ARR_AIRPORT VARCHAR2(5) Airport of arrival
. Identification of duplicated flights
The temporary merge table is scanned upon two criteria:
o
All flights that have the same FLUID are declared as duplicated.
o
Flights that have a different Fluid but the same callsign, departure airport and arrival airport can be duplicated if:
.
Condition 1: The difference of time between the airports of departure of potential duplicated flights is inferior to 600 minutes.
.
Condition 2 (Figure 17): The interval of time between the first event time of the reference flight and the last event time of the compared flight is less than 950 minutes and:
.
The average speed between the first flight leg of the first flight and the last flight leg of the second flight is 0 or within 110 – 750 knots range.
.
The average speed between the last flight leg of the first flight and the first flight leg of the second flight is 0 or within 110 -750 knots range.
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