The Laser Airborne Depth Sounder (LADS) Flight was a unit of the
Royal Australian Navy
The Royal Australian Navy (RAN) is the principal naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister of ...
. Unlike the rest of the flying units of the RAN, it was not controlled by the
Fleet Air Arm
The Fleet Air Arm (FAA) is one of the five fighting arms of the Royal Navy and is responsible for the delivery of naval air power both from land and at sea. The Fleet Air Arm operates the F-35 Lightning II for maritime strike, the AW159 Wil ...
from , but instead fell under the operational control of the
Australian Hydrographic Service at , providing a platform for the operation of the
laser airborne depth sounder system.
LADS Flight conducted its last sortie on 7 November 2019.
History
In the 1970s, the Royal Australian Navy's Hydrographic Service was still limited in its ability to survey the vastness of Australia's coastal waters, and was still producing charts on areas where surveying was incomplete or had not even taken place.
As a consequence, the RAN began to search for a way of effectively surveying the Australian coastline from the air, which led to the development of the Laser Airborne Depth Sounder system by the
Defence Science and Technology Organisation
The Defence Science and Technology Group (DSTG) is part of the Australian Department of Defence dedicated to providing science and technology support to safeguard Australia and its national interests. The agency's name was changed from Defenc ...
, a part of the Australian
Department of Defence Department of Defence or Department of Defense may refer to:
Current departments of defence
* Department of Defence (Australia)
* Department of National Defence (Canada)
* Department of Defence (Ireland)
* Department of National Defense (Philipp ...
, with trials beginning in 1977.
[Slade, in Oldham, ''100 Years of the Royal Australian Navy'', p. 171] In 1992, a new unit was formed to operate the system, the Laser Airborne Depth Sounder Flight, with the LADS system fitted to a highly modified
Fokker F27
The Fokker F27 Friendship is a turboprop airliner developed and manufactured by the Dutch aircraft manufacturer Fokker. It is the most numerous post-war aircraft manufactured in the Netherlands; the F27 was also one of the most successful Europe ...
aircraft.
This aircraft was subsequently replaced in 2009 by a modified
Bombardier Dash 8
The De Havilland Canada DHC-8, commonly known as the Dash 8, is a series of turboprop-powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. DHC was later bought by Boeing in 1988, then by Bombardier in 1992; then by ...
.
Operation
The LADS Flight was a joint operation between the Australian Hydrographic Service and the Fugro LADS Corporation, part of
Fugro
Fugro is a Dutch multinational public company headquartered in Leidschendam, Netherlands, that specializes in collecting and analysing geological data, both on land and at sea.
Employing approximately 9,000 people in 65 countries, Fugro serv ...
a
Dutch
Dutch commonly refers to:
* Something of, from, or related to the Netherlands
* Dutch people ()
* Dutch language ()
Dutch may also refer to:
Places
* Dutch, West Virginia, a community in the United States
* Pennsylvania Dutch Country
People E ...
corporation, which also runs hydrographic operations for the private sector. The aircraft itself was owned by the Fugro LADS Corporation, which also provides the flight crews and system maintenance technicians. Aircraft engineers came from the civilian contractor,
Surveillance Australia, while the hydrographic specialists are serving members of the RAN.
The flight was stationed at
Cairns in the
far north of
Queensland
)
, nickname = Sunshine State
, image_map = Queensland in Australia.svg
, map_caption = Location of Queensland in Australia
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, establishe ...
, but could be deployed to other locations for up to three months at a time; the aircraft had an operational endurance of up to seven hours for operations close to its base, reducing to four hours on station at a distance of up to 300
nautical miles
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. Historically, it was defined as the meridian arc length corresponding to one minute ( of a degree) of latitude. Today t ...
.
In December 2016, the aircraft deployed to the
South Island of New Zealand to assist in surveying the coast following the
Kaikoura earthquake.
Laser Airborne Depth Sounder
The Laser Airborne Depth Sounder (LADS) is an
airborne lidar bathymetry
Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. It can also be ...
system used for
hydrographic surveying by the
Australian Hydrographic Service (AHS).
[ The system uses the difference between the sea surface and the sea floor as calculated from the aircraft's altitude to generate hydrographic data.][
The lack of progress made in surveying Australia's territorial waters, most of which was unsurveyed or relying on Age of Sail-era ]charts
A chart (sometimes known as a graph) is a graphical representation for data visualization, in which "the data is represented by symbols, such as bars in a bar chart, lines in a line chart, or slices in a pie chart". A chart can represent tab ...
prompted the Royal Australian Navy
The Royal Australian Navy (RAN) is the principal naval force of the Australian Defence Force (ADF). The professional head of the RAN is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. CN is also jointly responsible to the Minister of ...
to seek a method of effectively surveying large areas from the air in the 1970s. The Defence Science and Technology Organisation
The Defence Science and Technology Group (DSTG) is part of the Australian Department of Defence dedicated to providing science and technology support to safeguard Australia and its national interests. The agency's name was changed from Defenc ...
developed the LADS system, with feasibility trials beginning 1977.
The LADS system is built around a Nd:YAG laser, which emits an infrared beam at 990 hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is sā1, meaning that o ...
. The beam is frequency doubled
Second-harmonic generation (SHG, also called frequency doubling) is a nonlinear optical process in which two photons with the same frequency interact with a nonlinear material, are "combined", and generate a new photon with twice the energy of ...
to produce a green laser. This is split into two beams, one infra-red, one green, by an optical coupler, with the infra-red beam aimed directly below the aircraft, and the green beam directed across the target area with a scanning mirror. The infra-red laser does not penetrate the water's surface, and its reflected pulse indicates the height of the aircraft above the surface. However, the green laser penetrates to the ocean floor, and the return pulse from the green laser indicates the height of the aircraft from the ocean floor; the difference between the two values is used to calculate the water's depth. The data from the lasers is not processed aboard the aircraft, but instead by a ground support team, with aircraft flight data and global positioning system
The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of the global navigation satellite sy ...
information used to help generate hydrographic readings. The aircraft makes multiple, overlapping passes of the target area to ensure accurate data is collected. The LADS system is capable of taking 990 soundings per second, with data points positioned apart across a swath up to wide. The system is capable of working with waters up to deep, and can be modified to perform land surveys of areas with an altitude variance less than
LADS entered service with the AHS in 1993.[ The equipment was initially fitted to a ]Fokker F27 Friendship
The Fokker F27 Friendship is a turboprop airliner developed and manufactured by the Dutch aircraft manufacturer Fokker. It is the most numerous post-war aircraft manufactured in the Netherlands; the F27 was also one of the most successful Eur ...
aircraft.[ In 2010, the system was installed in a ]de Havilland Canada Dash 8
The De Havilland Canada DHC-8, commonly known as the Dash 8, is a series of turboprop-powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. DHC was later bought by Boeing in 1988, then by Bombardier in 1992; then by ...
aircraft.[
]
References
Further reading
*
External links
Laser Airborne Depth Sounder Flight
ā Royal Australian Navy
ā Australian Hydrographic Service
{{Use dmy dates, date=June 2017
Australian naval aviation
Military units and formations established in 1992
Royal Australian Navy
Hydrography