Synthetic Aperture Radar (SAR) in the Australian Maritime Surveillance System

Mayor (Tek) Jon K.Ginting, Perwira TNI AU sedang tugas belajar di University of New South Wales at the Australian Defence Force Academy, Anggota Dewan Penasehat Harian TANDEF

Abstract
The geographical constellation of Australia gives a good value that there is no land boundary to concern. However, there are risks in having a long coastline and maritime zones. Therefore, maritime security aspect has paid an attention from the Government for years. The most concerns are directed to Australian northern approaches, as the biggest possibility of adversary will come from that particular area. This is the primary reason driving Australia to maintain a wide scope of elements within maritime surveillance system. Amongst some assets of Australian maritime surveillance system, Spaceborne Synthetic Aperture Radar (SAR) has been used for around 17 years.

Although it is not privately owned by Australia, its combination with the existing Over The Horizon Radar (OTHR) within the Jindalee Operating Radar Network (JORN) program has contributed significantly to provide up-to-date information and detection of northern approaches maritime activities. The existence of SAR has proven capable of reducing risk produced by the disadvantage of OTHR in bad weather. As understood, ensuring a huge area of Australian maritime zones requires a great effort and is never an easy task. Assessed from risk management perspective, SAR has proven to be capable of helping the system achieve its objective.

Introduction
Australia has a huge range of maritime assets and jurisdiction. With almost 60,000 km long coastline and large offshore jurisdiction (Geoscience Australia 2006, p.4), it requires a systematic effort to ensure the security and sovereignty of the sea are maintained. Bateman (2007) asserts that managing the civil dimension of securing Australia’s maritime approaches has over the years been reactive, lacking in strategic vision and generally uncoordinated. Amongst some critical areas Australia has to cover, northern approach is of a serious concern. It has been a major priority for the Australian Government (Fensom et al 1993). Northern region is obviously providing more strategic values for Australia than other regions; however, there are also greater challenges and risks. The biggest risk will rise if Australia could not manage to provide a proper maritime surveillance system capable of ensuring detection and warning of any adversary. The SAR is a method providing this expected capability in the Australian Maritime Surveillance System.

This essay will discuss the contribution of SAR to maritime surveillance system portfolio and to the achievement of Australian maritime surveillance objectives whereas the coverage will only be the SAR and not be the coordination and cooperation among elements within the overall Australia’s maritime surveillance system.

Australian Maritime Surveillance Challenges
There are certain facts that can provide an idea of what situation is faced by Australia (Sea Power Center Australia 2000):
a. Australia is an island continent in a maritime region,
b. Australia’s area of strategic interest is vast (the jurisdiction areas alone comprise almost 16 million square kilometres),
c. Australia and the nations of the region are dependent on the sea for transport,
d. Maritime forces possess significant access and influence in our region, and
e. Australia requires maritime forces capable of meeting the challenges of our strategic geography.

Basically, a maritime surveillance system has been run for many years. Nevertheless, when current and planned civil and defence surveillance system offer individual advantage, none of them provides a fully effective solution for the detection, classification and tracking of ships and boats, especially in terms of temporal and areal coverage, and robustness to cloud cover and time of day (Fensom et al 1993). The situation is also described by Bateman (2003) as “...characterized by less than optimum coordination and cooperation between the agencies involved...” Figure 1 below shows Australia’s maritime scope to secure.

The description above suggests that there are two practical issues in Australia’s maritime surveillance system:
a. providing a proper capability to detect, classify, and track any incoming ships and boats to Australia’s maritime zone, and
b. managing a wide range of entities responsible to maintain the security of Australia’s maritime.
Managing the Challenges
The ability to locate and monitor potentially hostile forces in the sea and air approaches and on Australia’s territory is essential to prevent or nullify threats to Australia’s interests (Department of Defence 1994). However, it is not merely the responsibility of the Defence Force. For this reason, Australian maritime surveillance is provided a radar network called JORN operating since 2003 and appears to be primary component of the portfolio. The JORN is controlled by a Joint Offshore Protection Command (JOPC) formed in March 2005. This organisation is responsible to both the Chief of Defence Force (CDF) and the Chief Executive Officer of Customs for conducts of military and civil maritime tasks respectively (Strengthening Australia’s Offshore Maritime Security 2005).

On the other hand, it is also necessary to use the advantage of SAR technology to provide early detection of ships and aircrafts coming to Australia. NASA defines SAR as a high-resolution ground-mapping technique that effectively synthesizes a large receiving antenna by processing the phase of the reflected radar return. A key advantage offered by SAR is its day/night and all-weather operation, together with the ability to scan extremely large areas at about 2000 km2 per second, far exceeding airborne capabilities (Fensom et al 1993). Compared to OTHR, SAR offers more strength against bad weather disturbance.

Project Management Overview
From the project management perspective, the advantage of SAR should be integrated with OTHR to cover its flaw, thus produce an optimum benefit for the whole portfolio. The SAR has so far been developed into more advanced models. It is a well proven technology, with SEASAT, SIR-A, SIR-B, and the Russian ALMAZ-1 now in history, ERS-1 and JERS-1 currently operating, and SIR-C, ERS-2 and the Canadian RADARSAT well into development (Fensom et al 1993). Australia has taken advantages from the European Space Agency (ESA) ERS-1 since its launching on 17 July 1991 (until its operation termination in 2000), followed by the second serial ERS-2 on 20 April 1995 (Geoscience Australia 2006).

Having said that the JORN’s OTHR as the primary asset for Australian maritime surveillance system has a significant drawback in terms of bad weather, taking the advantage of SAR’s capability into the portfolio is a measure to perfect the detection and identification process of incoming ships and aircrafts from northern approaches. The combination of two different characteristics of OTHR and SAR will provide a complete coverage of surveillance, thus minimise the probability of sea and air adversaries to enter Australia’s territory. The basic relationship of SAR and OTHR under the JOPC’s command can briefly be described as the picture below:

As the Australian maritime objective to protect Australia’s interests from sea adversaries is considered a very broad spectrum of tasks, taking SAR into the portfolio provides significant improvement to Australian surveillance capability. In spite of OTHR fast revisit time, its capability will be very limited in bad weather (as it depends on the clarity of signal pathway to and from ionosphere). This will not be an issue for spaceborne SAR; however, its 35-day revisit time is longer than that of OTHR (Fensom et al 1993). Its long revisit time can simply rise a risk of using SAR, however, combining it with the use of OTHR is a risk managing measure. For JOPC, the task of detecting and identifying suspicious target at any time and any weather will be much easier by combining their capabilities. As Thiry (2004) suggests that in a program, some projects will be better than individual with a coordinated management.

Conclusion
Australia, with its huge maritime area, requires a comprehensive set of maritime surveillance system which is aimed to maintain its sovereignty in the sea by providing a capability of detection, identification, interception and strike to incoming adversaries. For detection and identification needs, the JORN with its OTHR has been the major element for the system. Nonetheless, OTHR limitation in adapting with bad weather creates a risk potential that can endanger Australian security. This risk can be well-managed by applying SAR that performs better in bad weather condition, thus allow Australia’s maritime zones to be monitored at any time. The SAR provides capability the Australian needs, and with already-established JOPC to manage it with other surveillance assets, applying SAR as a part of the maritime surveillance portfolio will enhance the system, and finally ensure the Australian maritime zones and territorial security.

Reference List
Anonymous 2005, Strengthening Australia’s Offshore Maritime Security, viewed 1 April 2008

Bateman, Sam 2007, Securing Australia’s Maritime Approach, Security Challenges Vol.3 No. 3.

Department of Defence 1994, Defending Australia: Defence White Paper 1994, Australian Government Publishing Service, Canberra.

Fensom, D.S., Longstaff, I.D., Tuohy, I.R. 1993, An Equatorial Satellite Maritime Surveillance System, The Institution of Engineers Australia, Canberra.

Geoscience Australia 2006, ERS-1 Earth Resource Satellite, in Geoscience Australia: ACRES ERS-1- Earth Resource Satellite, viewed 9 April 2008

Sea Power Center Australia 2000, AUSTRALIAN MARITIME DOCTRINE – RAN DOCTRINE 1 – 2000, viewed 2 April 2008

Thiry, Michel 2004, ‘Program Management: A strategic decision management process’, in Morris, P.W.G., Pinto, J.K. (eds), The Wiley guide to managing projects, John Wiley and Sons, Hoboken, New Jersey.