The airspace over the large territory of Namibia has grown busier over time
due to high altitude traffic between Europe and the Republic of South Africa,
particularly during the FIFA World Cup – the football championship in 2010.
Provision of air traffic control and air safety has become urgent and the lack of
radar equipment and shortage of air traffic controllers at Namibian airports has
seriously threatened airspace safety over Namibia. Several airports had to be
closed. Namibian airspace was managed exclusively by radio communication
and aircrafts were separated by ICAO procedural separation standards.
This completely inadequate radar coverage resulted in an urgent need for
radars represented by MSS (Multi-sensor Surveillance System) for the entire area
of the country. This situation led to the decision to request for a Proposal (RFP)
issued by Namibian CAA (Civil Aviation Authorities) for the supply, optimisation
and commissioning of a Wide Area Multilateration System (WAM). There was a
need to cover a huge area with mountains reaching an elevation over 3,500 m.
The population density is one of the world’s lowest, which is combined with
the lack of an adequate and modern infrastructure. In addition, no construction
work is allowed within the large area of Etosha National Park (ca 100,00 km2).
ERA won the contract as a subcontractor to the French company Thales.
The ERA system is part of Thales’ Eurocat-X ATM system as the primary
surveillance source. The configuration of the system comprises remote Ground
Stations (GS), a redundant Central Processing Server (CPS) and a Management
System including a Remote Management Terminal. The stations are configured
as receiving sites (RXs) and receiving/transmitting sites (RXTXs). The ground
stations consist of 1090 MHz and GNSS receiving antennas, 1030 MHz transmitting
antennas and several electronic units which are housed under a shared
shielding case. ERA proposed the Distributed Time (DT ) system architecture for
the WAM system. The advantages of the chosen approach are as follows:
- Highly robust GS which minimize maintenance activity (due to a lack of infrastructure).
- No air-conditioning is necessary - no fans inside the GS, the modules are
designed to survive extreme outdoor conditions (completely dust-proof -
suitable for desert areas, immersion in 1 meter deep water for 30 minutes).
- All GS are equipped with batteries to ensure power back-up.
As the result of implementing the
above described MSS technology
for the area of Namibia, the Wide
Area Multilateration system in this
country is the largest system of its
kind in the world both in terms of
area and number of ground stations
deployed across the entire country.
The original Namibia WAM system
employs 36 widely separated and
unmanned ground based stations,
after two phases of extension the
number of stations have increased
to 55. Accuracy is usually less
than 200 meters, and in smaller
local configurations it can be less
than 50 meters. The system was
certified according to ICAO as safe
and capable of supporting aircraft
separations as low as 10 nautical
miles across Namibian air space.
WAM Namibia – the original deployment
The net of stations and coverage after the 1st extension.
“As a result of the
WAM system performance
we decided to
deploy an extension
around Walvis Bay
and in Caprivi with
being contemplated to
provide WAM redundancy
for Hosea Kutako
at Windhoek, as well
as Eros Airport.“
Thales Group is a French
company that designs and
builds electrical systems
and provides services for the
aerospace, defence, transportation
and security markets. It
is partially state-owned by the
French state and has operations
in more than 50 countries.
It has 68,000 employees
and is the 11th largest defence
contractor in the world.