1. The implementation of
extended surveillance by using ADS-B is the promising way to
increase the Air Traffic Control (ATC) systems efficiency.
At present, the extended surveillance realization provides
for the implementation of mode S SSR and ADS-B systems on
the base of:
- listening of extended squitters transmissions;
- mode 4 VDL;
- universal transceiver (UAT).
Although the realization of extended surveillance using
mode S SSR is the most usual way, it is likely to find its
application only in the areas of high air traffic intensity
due to economic reasons.
In the other areas the standard MSSRs allowing the ATC system
to get air traffic situation information independently of
airborne navigation systems and their data sources condition
are used and are likely to be used in future.
MSSR upgrading by adding the capability to receive the ADS-B
information allows to realize the extended surveillance
functions with minimum expenses and also to maintain the
surveillance independence using ADS-B data validity
monitoring.
2. The block diagram of
the MSSR-JAC modification for receiving the ADS-B data,
transmitted in extended squitters via the mode 4 VDL
channels (optional) is presented in Fig 1. The supplementary
equipment is shown in blue and grey. Four fixed antennas
with 90° beamwidth, located at
the antenna module are used for the extended squitters
reception. A four-channel receiver provides separate
receiving and decoding of squitters for each of four azimuth
sectors. The information on the same target from the
different sources is combined on the basis of the respective
3D tracks identity analysis.
Fig.1 Modified MSSR-JAC block
diagram.
3. Main
performance specifications of the modified MSSR-JAC are
given in the following table:
Parameter name
|
RBS |
UVD |
ADS |
En-route/
terminal |
En-route/
terminal |
Squitter |
| Coverage area |
|
|
|
| Max range, km |
465/250 |
465/250 |
400 |
| Min range, km |
1 |
1 |
0.25 |
|
Altitude, km |
20/12 |
20/12 |
20/12 |
| Elevation angle, deg |
0.3/45 |
0.3/45 |
0.3/45 |
| Number of targets |
|
|
|
| Per scan |
200/400 |
200 |
|
Modes |
A/C |
N/H |
Passive reception |
|
|
|
|
|
|
Accuracy (RMS) |
|
|
|
| Azimuth, deg |
0.8 |
0.12 |
|
| Range, m |
20 |
20 |
|
| Latitude, min |
|
|
GPS |
| Longitude, min |
|
|
GPS |
|
Altitude discrete, m |
30 |
10 |
GPS |
|
|
|
|
|
| Resolution |
|
|
|
| In azimuth, deg |
1 |
1.5 |
GPS |
| By range, m |
100 |
400 |
GPS |
|
Detection probability |
0.98 |
0.98 |
0.95 |
|
|
|
|
|
|
Scan rate, sec |
20..10/6..4 |
20..10/6..4 |
0.5..5 |
|
|
|
|
|
|
Extended surveillance data |
No |
No |
Yes |
|
|
