Defence Update

In short LADS is a mobile hydrographic surveying system that will deliver accurate, high density, digital depth and positional data from coastal waters. With the development phase completed, the system, made up of a converted Fokker Friendship and ground trailers, both specially equipped, is now undergoing final trials and will be accepted into service by the Royal Australian Navy by early 1993.

The project has been based at Technology Park, Adelaide for some 30 months since BHP Engineering and Vision Systems Limited were awarded the Department of Defence contract worth $40m in May, 1989. This was to design, manufacture and trial a production LADS for operational use by the Navy.

Defence scientists, led by Dr Bob Ward, the Chief Defence Scientist, Mr Bob Ramsay, Director of the Defence Science and Technology Organisation (DSTO) Surveillance Research Laboratory, and Mr Mike Penny, a Principal Research Scientist at SRL, point to the extraordinary capabilities that will flow from having production LADS operated by the RAN. Penny has been associated with the LADS project fro some 20 years.

Under the normal system of charting Australia’s waters out to the continental shelf, it has been estimated than it would take up to another 100 years to complete what is now only half done. DSTO and Navy officers estimate that the LADS system will save the ADF between $350m and $500m over the next 10 years. This is because it will not need to acquire or maintain as many surface survey craft, and produce the manpower to operate such vessels. Dr Ward estimates that LADS will speed up charting Australian waters seven to 10 times the rate that could be achieved by survey boats.

Perhaps almost as significant is that he believes that between 10 and 20 such systems could be sold overseas. This sales task falls to the prime contractor, BHP Engineering, whose LADS Project Director is Mr Paul McCowage.

At the launch of the production LADS system at Adelaide Airport on January 28, it was noted that a significant milestone in the development of airborne laser hydrography, and established Australia as a world leader in such specialised technology. The LADS system further offers complete, safe coverage of complex or dangerous areas unsuitable for surveying by surface vessels. In part that applies to the half of the Australian continental shelf which remains unsurveyed to acceptable standards.

The project managers say that from 500 metres above the sea, flying at 145 knots, unhindered by reefs or shallows, the Laser Airborne Depth Sounder surveys the sea floor at a rate in excess of 50 square kilometres an hour. The system measures water depths of up to 50 metres, and the hourly sea bed survey provides 10,000 soundings per kilometre spaced 10 metres apart in a swath 240 metres wide.

This rapid, cost effective project which is also a valuable addition to conventional echo sounder technology, is a far cry from the explorers like Cook and Flinders who started charting Australia’s huge coastline of one million square kilometres around 200 years ago. The LADS system is made up of two major functional groups – the airborne laser, navigation and data acquisition equipment mounted in a Fokker F27-500, and ground based data analysis and support equipment.

BHP Engineering provides project, trials and logistic management, while Vision Systems provides technical management, and carried out the design and construction of the airborne computing hardware and software. Sub-contractors to BHP Engineering are, or have been, Eastwest Airlines, AWA Defence Industries, British Aerospace Australia, andHoneywell Australia.

The system is based on early researching by DSTO into the viability of airborne laser depth measurement, and has attracted overseas interest which confirms the views that LADS has a worldwide market potential. The infrared laser, which is operated at 168 pulses per second, is mounted on a platform which is stabilised in pitch, roll and drift. The output from the laser is frequency doubled to produce visible green light at the wavelength of 532 nanometres. The infrared pulses are transmitted vertically from the aircraft, and reflect from the sea surface to produce an initial reference. The green pulses, which reflect from both the sea surface and bottom, are scanned by way of a moving mirror at right angles to the aircraft track to form a rectilinear pattern of soundings.

The returning pulses are directed via sensitive receivers to onboard computers which extract depth information from the time difference between surface and bottom returns. The data plus positional data determined by the satellite Global Positioning System (GPS) is recorded on tape for subsequent analysis by the ground equipment. Following validation the data is ready to be used in the preparation of charts. The contractors and scientists estimate that complete charting of Australian waters should now take only 10 to 15 years.

In his launch speech, Mr Gordon Bilney said that quite rightly LADS was being pushed as “a remarkable, new Australian innovation” which was the product of nearly two decades of research and development. “To many of our competitors, including the Japanese, there would be no paradox,” he said. “They are used to inter-generational R&D, investment that requires decades to pay off, and product development cycles than can span much of an individual’s working life. “We are not, or haven’t been like that,” Bilney said. But he added that institutions like DSTO demonstrate that when we focus on the long term we can generate ideas, technologies and products than can match and beat the best in the world. “The laser airborne depth sounder is one such technology,” he said.

The Minister paid a warm tribute to Mr Mike Penny, a Principal Research Scientist at DSTO’s Surveillance Research Laboratory who has worked on LADS since its inception. “Like many such innovations, it owes much to the ingenuity, intelligence and perseverance of an individual, albeit supported by a resourceful and dedicated team,” Bilney said. “Back in 1969 Mike demonstrated a new and highly productive application of laser mapping the continent by measuring the transmission and reception of laser pulses bounced off the landscope by an aircraft mounted laser generator. Three years later he and his team applied the technology to the charting of our coastal waters,” he said.

Bilney said that all sounded reasonably straight forward, but was hardly so when it was considered what technical capacity was needed to generate, record, and analyse 500,000 soundings made over 50 square kilometres each hour. “Much of the refinement of the original idea has required countless hours of painstakingly precise scientific work – in total, the DSTO research effort amounts to more than 200 staff years,” the Minister added.

Then he detailed the efforts expended in developing and streamlining the system to maximise its capacity and deployability and to ensure it delivered accurate information taking account of flight distortions. “Without him there would be no LADS project at Technology Park, and no talk of export dollars, profits and jobs,” Bilney said.

He noted that for his efforts in developing the system, Mike Penny was awarded the Public Service Medal in 1990, and in addition he received several honours from his professional colleagues