Misplaced Pages

#484515

112-608: HMAS Harman is a Royal Australian Navy (RAN) base that serves as a communications and logistics facility. The main base is located in the Australian capital of Canberra , and is geographically recognised as the suburb of Harman (postcode 2600) in the District of Jerrabomberra . Established in the late 1930s as the Royal Australian Navy Wireless/Transmitting Station Canberra , the facility

224-699: A large number of civilian-crewed vessels under contract to the Australian Defence Force. RAN personnel utilise the following small arms: There are currently several major projects underway that will see upgrades to RAN capabilities. The RAN currently has forces deployed on seven major operations: Direction finding RDF systems can be used with any radio source, although very long wavelengths (low frequencies) require very large antennas, and are generally used only on ground-based systems. These wavelengths are nevertheless used for marine radio navigation as they can travel very long distances "over

336-728: A commission by the Governor-General as Commander-in-Chief on behalf of His Majesty King Charles III. Naval officers are trained at the Royal Australian Naval College (HMAS Creswell ) in Jervis Bay as well as the Australian Defence Force Academy in Canberra. Royal Australian Navy Other Ranks wear "right arm rates" insignia, called "Category Insignia" to indicate specialty training qualifications. This

448-621: A common center point. A movable switch could connect opposite pairs of these wires to form a dipole, and by rotating the switch the operator could hunt for the strongest signal. The US Navy overcame this problem, to a point, by mounting antennas on ships and sailing in circles. Such systems were unwieldily and impractical for many uses. A key improvement in the RDF concept was introduced by Ettore Bellini and Alessandro Tosi in 1909 (U.S. Patent 943,960). Their system used two such antennas, typically triangular loops, arranged at right angles. The signals from

560-530: A directional antenna is used which is more sensitive in certain directions than in others. Many antenna designs exhibit this property. For example, a Yagi antenna has quite pronounced directionality, so the source of a transmission can be determined by pointing it in the direction where the maximum signal level is obtained. Since the directional characteristics can be very broad, large antennas may be used to improve precision, or null techniques used to improve angular resolution. A simple form of directional antenna

672-498: A directional antenna pattern, then the amplitude may be included in the comparison. Typically, the correlative interferometer DF system consists of more than five antenna elements. These are scanned one after the other via a specific switching matrix. In a multi-channel DF system n antenna elements are combined with m receiver channels to improve the DF-system performance. Radio direction finding , radio direction finder , or RDF ,

784-441: A few tens of kilometres. For aircraft, where the horizon at altitude may extend to hundreds of kilometres, higher frequencies can be used, allowing much smaller antennas. An automatic direction finder, often capable of being tuned to commercial AM radio transmitters, is a feature of almost all modern aircraft. For the military, RDF systems are a key component of signals intelligence systems and methodologies. The ability to locate

896-632: A fleet of mobile DF vehicles around the UK. If a transmitter was identified by the fixed DF stations or voluntary interceptors, the mobile units were sent to the area to home in on the source. The mobile units were HF Adcock systems. By 1941 only a couple of illicit transmitters had been identified in the UK; these were German agents that had been "turned" and were transmitting under MI5 control. Many illicit transmissions had been logged emanating from German agents in occupied and neutral countries in Europe. The traffic became

1008-581: A fleet unit within a larger imperial force, controlled centrally by the British Admiralty . In 1908–09, a compromise solution was pursued, with the Australian government agreeing to establish a force for local defence but that would be capable of forming a fleet unit within the Royal Navy, albeit without central control. As a result, the navy's force structure was set at "one battlecruiser, three light cruisers, six destroyers and three submarines". The first of

1120-635: A gymnasium. The base covers an area of 2.5 square kilometres (0.97 sq mi). 970 people work at Harman . Functions performed at Harman include: On 11 July 2013, ex-CIA contractor Edward Snowden revealed documents that alleged Harman , amongst three other locations in Australia and one in New Zealand, were amongst those used in the PRISM surveillance program conducted by various United States intelligence agencies. The Defence Network Operations Centre (DNOC)

1232-437: A known wave angle (reference data set). For this, at least three antenna elements (with omnidirectional reception characteristics) must form a non-collinear basis. The comparison is made for different azimuth and elevation values of the reference data set. The bearing result is obtained from a correlative and stochastic evaluation for which the correlation coefficient is at a maximum. If the direction finding antenna elements have

SECTION 10

#1733093535485

1344-500: A landfall. In the United States, commercial AM radio stations were required to broadcast their station identifier once per hour for use by pilots and mariners as an aid to navigation. In the 1950s, aviation NDBs were augmented by the VOR system, in which the direction to the beacon can be extracted from the signal itself, hence the distinction with non-directional beacons. Use of marine NDBs

1456-399: A multiple channel receiver system. One form of radio direction finding works by comparing the signal strength of a directional antenna pointing in different directions. At first, this system was used by land and marine-based radio operators, using a simple rotatable loop antenna linked to a degree indicator. This system was later adopted for both ships and aircraft, and was widely used in

1568-517: A number of radio DF units located at civil and military airports and certain HM Coastguard stations. These stations can obtain a "fix" of the aircraft and transmit it by radio to the pilot. Radio transmitters for air and sea navigation are known as beacons and are the radio equivalent to a lighthouse . The transmitter sends a Morse Code transmission on a Long wave (150 – 400 kHz) or Medium wave (520 – 1720 kHz) frequency incorporating

1680-459: A number of small antennas fixed to a circular card, with all of the processing performed by software. Early British radar sets were also referred to as RDF, which was a deception tactic. However, the terminology was not inaccurate; the Chain Home systems used separate omnidirectional broadcasters and large RDF receivers to determine the location of the targets. In one type of direction finding,

1792-551: A receiving and a transmitting station in Canberra in 1937, with the transmitting station sited at Ginninderra Creek in Belconnen , approximately 20 kilometres (12 mi) north-west of the main receiving facility. Construction of the transmission facility (Royal Australian Navy Wireless/Transmitting Station Canberra) commenced in November 1938. The facility established on 20 April 1939 and started transmitting on 22 December 1939. Work on

1904-456: A ring and use electronic switching to rapidly select dipoles to feed into the receiver. The resulting signal is processed and produces an audio tone. The phase of that audio tone, compared to the antenna rotation, depends on the direction of the signal. Doppler RDF systems have widely replaced the huff-duff system for location of fleeting signals. The various procedures for radio direction finding to determine position at sea are no longer part of

2016-598: A small loop's null. For much higher frequencies still, such as millimeter waves and microwaves , parabolic antennas or "dish" antennas can be used. Dish antennas are highly directional, with the parabolic shape directing received signals from a very narrow angle into a small receiving element mounted at the focus of the parabola. More sophisticated techniques such as phased arrays are generally used for highly accurate direction finding systems. The modern systems are called goniometers by analogy to WW II directional circuits used to measure direction by comparing

2128-430: A suitable oscilloscope, and he presented his new system in 1926. In spite of the system being presented publicly, and its measurements widely reported in the UK, its impact on the art of RDF seems to be strangely subdued. Development was limited until the mid-1930s, when the various British forces began widespread development and deployment of these " high-frequency direction finding ", or "huff-duff" systems. To avoid RDF,

2240-811: A troublesome German coastal raider. The SMS Emden and HMAS Sydney met in the Battle of Cocos, the Emden was destroyed in Australia's first naval victory. Following the almost complete destruction of the East Asia Squadron in the Battle of the Falklands by the Royal Navy, the RAN became able to be reassigned to other naval theatres of the war. On 28 February 1915, the Royal Australian Naval Bridging Train (RANBT)

2352-489: A wider electronic warfare suite. Several distinct generations of RDF systems have been used over time, following new developments in electronics. Early systems used mechanically rotated antennas that compared signal strengths from different directions, and several electronic versions of the same concept followed. Modern systems use the comparison of phase or doppler techniques which are generally simpler to automate. Modern pseudo-Doppler direction finder systems consist of

SECTION 20

#1733093535485

2464-800: Is Chief of Navy (CN) Vice Admiral Mark Hammond AM, RAN. The Chief of Navy is also jointly responsible to the Minister for Defence (MINDEF) and the Chief of the Defence Force (CDF). The Department of Defence , which is a part of the Australian Public Service , administers the ADF, and ergo, the Royal Australian Navy. In 2023, the Surface Fleet Review was introduced to outline the future of

2576-568: Is a holdover from the Royal Navy. The Warrant Officer of the Navy (WO-N) is an appointment held by the most senior sailor in the RAN and holds the rank of warrant officer (WO). However, the WO-N does not wear the WO rank insignia; instead, they wear the special insignia of the appointment. The WO-N appointment has similar equivalent appointments in the other services, each holding the rank of warrant officer, each being

2688-437: Is formed. The CDTs have two primary roles: As of June 2023, the RAN has 14,745 permanent full-time personnel, 172 gap-year personnel, and 4,607 reserve personnel. The permanent full-time trained force consists of 3,070 commissioned officers, and 9,695 enlisted personnel. While male personnel made up 75.9% of the permanent full-time force, while female personnel made up 24%. The RAN has the second-highest percentage of women in

2800-457: Is known as radio direction finding or sometimes simply direction finding ( DF ). Using two or more measurements from different locations, the location of an unknown transmitter can be determined; alternately, using two or more measurements of known transmitters, the location of a vehicle can be determined. RDF is widely used as a radio navigation system, especially with boats and aircraft. RDF systems can be used with any radio source, although

2912-702: Is located at HMAS  Kuttabul , Sydney and the second, Fleet Base West , is located at HMAS  Stirling , near Perth. In addition, three other bases are home to the majority of the RAN's minor war vessels: HMAS  Cairns , in Cairns, HMAS  Coonawarra , in Darwin, and HMAS  Waterhen , in Sydney. The Clearance Diving Branch is composed of two Clearance Diving Teams (CDT) that serve as parent units for naval clearance divers: When clearance divers are sent into combat, Clearance Diving Team Three (AUSCDT THREE)

3024-517: Is now only one position as the loop rotates 360° at which there is zero current. This acts as a phase reference point, allowing the correct null point to be identified, removing the 180° ambiguity. A dipole antenna exhibits similar properties, as a small loop, although its null direction is not as "sharp". The Yagi-Uda antenna is familiar as the common VHF or UHF television aerial. A Yagi antenna uses multiple dipole elements, which include "reflector" and "director" dipole elements. The "reflector"

3136-428: Is often stated was a deception. In fact, the Chain Home systems used large RDF receivers to determine directions. Later radar systems generally used a single antenna for broadcast and reception, and determined direction from the direction the antenna was facing. The earliest experiments in RDF were carried out in 1888 when Heinrich Hertz discovered the directionality of an open loop of wire used as an antenna. When

3248-608: Is one of the largest and most sophisticated naval forces in the South Pacific region , with a significant presence in the Indian Ocean and worldwide operations in support of military campaigns and peacekeeping missions. The Commonwealth Naval Forces were established on 1 March 1901, with the amalgamation of the six separate colonial naval forces , following the Federation of Australia . The Royal Australian Navy initially consisted of

3360-409: Is the loop aerial . This consists of an open loop of wire on an insulating frame, or a metal ring that forms the antenna's loop element itself; often the diameter of the loop is a tenth of a wavelength or smaller at the target frequency. Such an antenna will be least sensitive to signals that are perpendicular to its face and most responsive to those arriving edge-on. This is caused by the phase of

3472-496: Is the hub of the third largest communications network in Australia after Telstra and Optus . The DNOC provides network support for military operations throughout the Australian Defence Force . During 2012 and 2013 it was reported that the expansion of communication facilities at Harman had resulted in budget cost overruns in excess of the original budget of A$ 90 million. A revised estimate of A$ 163 million

HMAS Harman - Misplaced Pages Continue

3584-448: Is the longest dipole element and blocks nearly all the signal coming from behind it, hence a Yagi has no front vs. back directional ambiguity: The maximum signal only occurs when the narrowest end of the Yagi is aimed in the direction from which the radio waves are arriving. With a sufficient number of shorter "director" elements, a Yagi's maximum direction can be made to approach the sharpness of

3696-858: The Mediterranean , the Red Sea , the Persian Gulf , the Indian Ocean , and off the West African coast . Following the outbreak of the Pacific War and the virtual destruction of Allied naval forces in Southeast Asia , the RAN operated more independently, defending against Axis naval activity in Australian waters , or participating in United States Navy offensives. As the navy took on an even greater role, it

3808-627: The Solomon Islands . The high demand for personnel in the Second World War led to the establishment of the Women's Royal Australian Naval Service (WRANS) branch in 1942, where over 3,000 women served in shore-based positions. The WRANS was disbanded in 1947, but then re-established in 1951 during the Cold War. It was given permanent status in 1959, and the RAN was the final branch to integrate women in

3920-526: The aviation world. Starting in the 1950s, these beacons were generally replaced by the VOR system, in which the bearing to the navigational aid is measured from the signal itself; therefore no specialized antenna with moving parts is required. Due to relatively low purchase, maintenance and calibration cost, NDBs are still used to mark locations of smaller aerodromes and important helicopter landing sites. Similar beacons located in coastal areas are also used for maritime radio navigation, as almost every ship

4032-447: The ionosphere . The RDF station might now receive the same signal from two or more locations, especially during the day, which caused serious problems trying to determine the location. This led to the 1919 introduction of the Adcock antenna (UK Patent 130,490), which consisted of four separate monopole antennas instead of two loops, eliminating the horizontal components and thus filtering out

4144-411: The sky waves being reflected down from the ionosphere. Adcock antennas were widely used with Bellini–Tosi detectors from the 1920s on. The US Army Air Corps in 1931 tested a primitive radio compass that used commercial stations as the beacon. A major improvement in the RDF technique was introduced by Robert Watson-Watt as part of his experiments to locate lightning strikes as a method to indicate

4256-477: The 1920s and early 1930s, the RAN was drastically reduced in size due to a variety of factors including political apathy and economic hardship as a result of the Great Depression . In this time the focus of Australia's naval policy shifted from defence against invasion to trade protection, and several fleet units were sunk as targets or scrapped. By 1923, the size of the navy had fallen to eight vessels, and by

4368-406: The 1930s and 1940s. On pre- World War II aircraft, RDF antennas are easy to identify as the circular loops mounted above or below the fuselage. Later loop antenna designs were enclosed in an aerodynamic, teardrop-shaped fairing. In ships and small boats, RDF receivers first employed large metal loop antennas, similar to aircraft, but usually mounted atop a portable battery-powered receiver. In use,

4480-521: The 1960s, many of these radios were actually made by Japanese electronics manufacturers, such as Panasonic , Fuji Onkyo , and Koden Electronics Co., Ltd. In aircraft equipment, Bendix and Sperry-Rand were two of the larger manufacturers of RDF radios and navigation instruments. Single-channel DF uses a multi-antenna array with a single channel radio receiver. This approach to DF offers some advantages and drawbacks. Since it only uses one receiver, mobility and lower power consumption are benefits. Without

4592-543: The 20th century a feature of most aircraft, but is being phased out. For the military, RDF is a key tool of signals intelligence . The ability to locate the position of an enemy transmitter has been invaluable since World War I, and played a key role in World War II's Battle of the Atlantic . It is estimated that the UK's advanced " huff-duff " systems were directly or indirectly responsible for 24% of all U-boats sunk during

HMAS Harman - Misplaced Pages Continue

4704-624: The ANMEF departed Sydney for training in Townsville before the rendezvous with other RAN vessels in Port Moresby . On 29 August, four cruisers and HMAS Australia assisted New Zealand's Samoa Expeditionary Force in landing at Apia , and committing a bloodless takeover of German Samoa. Additionally, the RAN captured German merchant vessels, disrupting German merchant shipping in the Pacific. On 7 September,

4816-461: The ANMEF, now including HMAS Australia , three destroyers, and two each of cruisers and submarines, departed for Rabaul. A few days later, on 9 September, HMAS Melbourne landed a party to destroy the island's wireless station, though the German administration promptly surrendered. Between 11 and 12 September, landings were put ashore at Kabakaul, Rabaul and Herbertshohe; it was during this period that

4928-569: The Asia-Pacific region and operated alongside the Royal Navy and United States Navy off Korea, Malaysia, and Vietnam. Since the end of the Cold War, the RAN has been part of Coalition forces in the Persian Gulf and Indian Ocean, operating in support of Operation Slipper and undertaking counter piracy operations. It was also deployed in support of Australian peacekeeping operations in East Timor and

5040-601: The Australian Capital Territory and southern New South Wales. The base also includes a tri-service "Multi-User Depot". This depot hosts reserve units from the Australian Army and Royal Australian Air Force, and cadet units of the Australian Navy Cadets , Australian Army Cadets, and Australian Air Force Cadets . Initially, the facilities at Harman included Number One Receiving Station, which became

5152-630: The Australian military in 1985. The strategic command structure of the RAN was overhauled during the New Generation Navy changes. The RAN is commanded through Naval Headquarters (NHQ) in Canberra . NHQ is responsible for implementing policy decisions handed down from the Department of Defence and for overseeing tactical and operational issues that are the purview of the subordinate commands. Beneath NHQ are two subordinate commands: Fleet Command

5264-589: The Communications Centre, an aerial farm behind the building, a direction finding hut located 1.2 kilometres (0.75 mi) away on a ridge, cottages and guard houses. Later, Number Two Receiving station was built for 'special tasks', a recreation hall was opened 27 April 1941, and a mess hall was finished around the end of 1940. In 1943, a second mess was built. The Morgan Dunbar Oval and Sir Victor Smith Oval are located in Harman . There are also tennis courts and

5376-572: The Germans had developed a method of broadcasting short messages under 30 seconds, less than the 60 seconds that a trained Bellini-Tosi operator would need to determine the direction. However, this was useless against huff-duff systems, which located the signal with reasonable accuracy in seconds. The Germans did not become aware of this problem until the middle of the war, and did not take any serious steps to address it until 1944. By that time huff-duff had helped in about one-quarter of all successful attacks on

5488-583: The Navy. The navy was formed in 1901 as the Commonwealth Naval Forces ( CNF ) through the amalgamation of the colonial navies of Australia following the federation of Australia . Although it was originally intended for local defence, it became increasingly responsible for regional defence as the British Empire started to diminish its influence in the South Pacific. The Royal Australian Navy

5600-455: The N–S (North-South) and E–W (East-West) signals that will then be passed to the receiver. In the receiver, the bearing angle can then be computed by taking the arctangent of the ratio of the N–S to E–W signal. The basic principle of the correlative interferometer consists in comparing the measured phase differences with the phase differences obtained for a DF antenna system of known configuration at

5712-525: The Pacific and Indian Oceans up to the early years of the Second World War. During its history, the Royal Australian Navy has participated in a number of major wars, including the First and Second World Wars, Korean War, Malayan Emergency, Indonesia-Malaysia Confrontation and the Vietnam War. As of 2024, the RAN consists of over 52 commissioned vessels, 11 non-commissioned vessels and over 16,000 personnel. The navy

SECTION 50

#1733093535485

5824-557: The RAN as the stone frigate HMAS Harman on 1 July 1943. Harman provided radio coverage of the Pacific Ocean during the war, and provided communications intercepts for the FRUMEL signals intelligence unit. Women of the Women's Royal Australian Naval Service (WRANS), formed in 1941, operated the equipment. In addition to its communications role, Harman provides Navy administrative and logistic functions to all Navy personnel located in

5936-838: The RAN at the Royal Australian Naval College, HMAS Creswell. From July 2020, Maritime Spiritual Wellbeing Officers (MSWOs) were introduced to the Navy Chaplaincy Branch, designed to give Navy people and their families with professional, non-religious pastoral care and spiritual support. In the Royal Australian Navy, Chaplains and MSWOs are commissioned officers without rank. For reasons of protocol, ceremonial occasions and for saluting purposes, they are, where appropriate, normally grouped with Commanders (O-5). . The more senior Division 4 Senior Chaplains are grouped with Captains (O-6) and Division 5 Principal Chaplains are grouped with Commodores (O-7), but their rank slide remains

6048-651: The RAN submarine HMAS AE1 became the first ever vessel of the new navy to be sunk. The Australian Squadron was placed under control of the British Admiralty , and was moreover tasked with protecting Australian shipping. On 1 November, the RAN escorted the First Australian Imperial Force convoy from Albany, WA and set for the Khedivate of Egypt , which was soon to become the Sultanate of Egypt . On 9 November, HMAS Sydney began hunting for SMS Emden ,

6160-703: The RAN's new vessels, the destroyer HMAS Yarra , was completed in September 1910, and by the outbreak of the First World War the majority of the planned fleet had been realised. On 10 July 1911, the CNF was granted "Royal" status by King George V . Following the British Empire's declaration of war on Germany , the British War Office tasked the capture of German New Guinea to the Australian Government . This

6272-433: The RDF operator would first tune the receiver to the correct frequency, then manually turn the loop, either listening or watching an S meter to determine the direction of the null (the direction at which a given signal is weakest) of a long wave (LW) or medium wave (AM) broadcast beacon or station (listening for the null is easier than listening for a peak signal, and normally produces a more accurate result). This null

6384-540: The U-boat fleet. Several developments in electronics during and after the Second World War led to greatly improved methods of comparing the phase of signals. In addition, the phase-locked loop (PLL) allowed for easy tuning in of signals, which would not drift. Improved vacuum tubes and the introduction of the transistor allowed much higher frequencies to be used economically, which led to widespread use of VHF and UHF signals. All of these changes led to new methods of RDF, and its much more widespread use. In particular,

6496-412: The UK was installing sufficient DF stations to cover the entire area to receive skywave signals reflected back from the ionised layers in the upper atmosphere. Even with the expanded network, some areas were not adequately covered and for this reason up to 1700 voluntary interceptors (radio amateurs) were recruited to detect illicit transmissions by ground wave . In addition to the fixed stations, RSS ran

6608-403: The UK, and Search and Rescue helicopters have direction finding receivers for marine VHF signals and the 121.5 MHz homing signals incorporated in EPIRB and PLB beacons, although modern GPS-EPIRBS and AIS beacons are slowly making these redundant. A radio direction finder ( RDF ) is a device for finding the direction, or bearing , to a radio source. The act of measuring the direction

6720-450: The ability to compare the phase of signals led to phase-comparison RDF, which is perhaps the most widely used technique today. In this system the loop antenna is replaced with a single square-shaped ferrite core , with loops wound around two perpendicular sides. Signals from the loops are sent into a phase comparison circuit, whose output phase directly indicates the direction of the signal. By sending this to any manner of display, and locking

6832-400: The ability to look at each antenna simultaneously (which would be the case if one were to use multiple receivers, also known as N-channel DF) more complex operations need to occur at the antenna in order to present the signal to the receiver. The two main categories that a single channel DF algorithm falls into are amplitude comparison and phase comparison . Some algorithms can be hybrids of

SECTION 60

#1733093535485

6944-429: The aircraft's radio set. Bellini–Tosi direction finders were widespread from the 1920s into the 1950s. Early RDF systems were useful largely for long wave signals. These signals are able to travel very long distances, which made them useful for long-range navigation. However, when the same technique was being applied to higher frequencies, unexpected difficulties arose due to the reflection of high frequency signals from

7056-494: The antenna was aligned so it pointed at the signal it produced maximum gain, and produced zero signal when face on. This meant there was always an ambiguity in the location of the signal: it would produce the same output if the signal was in front or back of the antenna. Later experimenters also used dipole antennas , which worked in the opposite sense, reaching maximum gain at right angles and zero when aligned. RDF systems using mechanically swung loop or dipole antennas were common by

7168-471: The antennas were sent into coils wrapped around a wooden frame about the size of a pop can , where the signals were re-created in the area between the coils. A separate loop antenna located in this area could then be used to hunt for the direction, without moving the main antennas. This made RDF so much more practical that it was soon being used for navigation on a wide scale, often as the first form of aerial navigation available, with ground stations homing in on

7280-459: The base is Commander David Luck, RAN. In 1924, the Imperial Defence Committee's Communications Sub-Committee examined Australian coastal radio stations, and recommended the modernisation of the stations at Darwin, Perth, Rabaul, and Townsville. A year later, the Australian Commonwealth Naval Board (ACNB) made a recommendation that two wireless stations be provided for the Navy in Canberra and Darwin. These would be strategic stations in addition to

7392-405: The coastal stations. Canberra was chosen as its distance from the coast would increase its protection from attack. Planning continued in 1935, where a new Canberra station would add to the coverage area of Rugby , and function as a fall back in the event of the destruction of submarine cables, or the Hong Kong or Singapore wireless telegraphy stations. The Australian government decided to build

7504-450: The correct bearing and allowed the navigator to avoid plotting a bearing 180 degrees opposite the actual heading. The U.S. Navy RDF model SE 995 which used a sense antenna was in use during World War I. After World War II, there were many small and large firms making direction finding equipment for mariners, including Apelco , Aqua Guide, Bendix , Gladding (and its marine division, Pearce-Simpson), Ray Jefferson, Raytheon , and Sperry . By

7616-563: The current Royal Australian Navy structure is O-10, an admiral who serves as the Chief of the Defence Force (CDF) when the position is held by a Naval Officer. The navy has a O-11 position Admiral of the Fleet that is honorary and is currently held by Charles III , King of Australia . O-8 (rear admiral) to O-11 (admiral of the fleet) are referred to as flag officers , O-5 (commander) and above are referred to as senior officers , while S-1 (midshipman) to O-4 (lieutenant commander) are referred to as junior officers . All RAN Officers are issued

7728-529: The differences in two or more matched reference antennas' received signals, used in old signals intelligence (SIGINT). A modern helicopter -mounted direction finding system was designed by ESL Incorporated for the U.S. Government as early as 1972. Time difference of arrival techniques compare the arrival time of a radio wave at two or more different antennas and deduce the direction of arrival from this timing information. This method can use mechanically simple non-moving omnidirectional antenna elements fed into

7840-451: The direction of thunderstorms for sailors and airmen. He had long worked with conventional RDF systems, but these were difficult to use with the fleeting signals from the lightning. He had early on suggested the use of an oscilloscope to display these near instantly, but was unable to find one while working at the Met Office . When the office was moved, his new location at a radio research station provided him with both an Adcock antenna and

7952-467: The eastern side of the site, housing the electrical engineer-in-charge and the sailors who maintained the transmitters and antennas. These were removed in the late 1980s, although the mess building remained, with personnel moving into housing in the growing suburbs that gradually encroached on the site. The station ended transmissions on 1 June 2005, and the remaining structures on the site were demolished in December 2006 to allow for residential development on

8064-539: The end of the decade it had fallen further to five, with just 3,500 personnel. In the late 1930s, as international tensions increased, the RAN was modernised and expanded, with the service receiving primacy of funding over the Army and Air Force during this time as Australia began to prepare for war. Early in the Second World War , RAN ships again operated as part of Royal Navy formations, many serving with distinction in

8176-459: The first Australian casualties and deaths of the war occurred. On 14 September, HMAS Encounter barraged an enemy position at Toma with shells; it was the first time the RAN had fired upon an enemy and had shelled an inland location. On 17 September, German New Guinea surrendered to the encroaching ANMEF, with the overall campaign a success and exceeded the objectives set by the War Office. However,

8288-476: The former New South Wales, Victorian, Queensland, Western Australian, South Australian and Tasmanian ships and resources of their disbanded navies. The Defence Act 1903 established the operation and command structure of the Royal Australian Navy. When policymakers sought to determine the newly established force's requirements and purpose, there were arguments about whether Australia's naval force would be structured mainly for local defence or designed to serve as

8400-416: The ground, and thereby provided excellent great circle route ground wave propagation that pointed directly to the transmitter. Methods of performing RDF on longwave signals was a major area of research during the 1900s and 1910s. Antennas are generally sensitive to signals only when they have a length that is a significant portion of the wavelength, or larger. Most antennas are at least 1 ⁄ 4 of

8512-401: The horizon", which is valuable for ships when the line-of-sight may be only a few tens of kilometres. For aerial use, where the horizon may extend to hundreds of kilometres, higher frequencies can be used, allowing the use of much smaller antennas. An automatic direction finder , which could be tuned to radio beacons called non-directional beacons or commercial AM radio broadcasters, was in

8624-545: The incoming signal. The popular Watson-Watt method uses an array of two orthogonal coils (magnetic dipoles) in the horizontal plane, often completed with an omnidirectional vertically polarized electric dipole to resolve 180° ambiguities. The Adcock antenna array uses a pair of monopole or dipole antennas that takes the vector difference of the received signal at each antenna so that there is only one output from each pair of antennas. Two of these pairs are co-located but perpendicularly oriented to produce what can be referred to as

8736-413: The intersecting bearings, the navigator could locate the relative position of his ship or aircraft. Later, RDF sets were equipped with rotatable ferrite loopstick antennas, which made the sets more portable and less bulky. Some were later partially automated by means of a motorized antenna (ADF). A key breakthrough was the introduction of a secondary vertical whip or 'sense' antenna that substantiated

8848-520: The location of the station and its transmitter, which can reduce the accuracy of the 'fix' when approaching the broadcast city. A second factor is that some AM radio stations are omnidirectional during the day, and switch to a reduced power, directional signal at night. RDF was once the primary form of aircraft and marine navigation. Strings of beacons formed "airways" from airport to airport, while marine NDBs and commercial AM broadcast stations provided navigational assistance to small watercraft approaching

8960-575: The main facility started in early 1939, with the facility registered with the Postmaster General's Department on 20 July 1939 under the name 'Harman'. The name was derived from the surnames of the two officers responsible for naming the new naval stations: Commander Neville Har vey of the Royal Navy , and RAN Lieutenant Commander Jack Bolton New man . As the ACNB had paid little attention to the proposals for

9072-539: The maritime safety system GMDSS , which has been in force since 1999. The striking cross frame antenna with attached auxiliary antenna can only be found on the signal masts of some older ships because they do not interfere there and dismantling would be too expensive. Modern positioning methods such as GPS, DGPS, radar and the now-outdated Loran C have radio direction finding methods that are imprecise for today's needs. Radio direction finding networks also no longer exist. However rescue vessels, such as RNLI lifeboats in

9184-729: The most senior sailor/soldier/airman in that service, and each wearing their own special insignia rather than their rank insignia. The Australian Army equivalent is the Regimental Sergeant Major of the Army (RSM-A) and the Royal Australian Air Force equivalent is the Warrant Officer of the Air Force (WOFF-AF). Chaplains in the Royal Australian Navy are commissioned officers who complete the same training as other officers in

9296-464: The names of previous wireless stations before implementing them, the two men proposed their combined names for the Canberra facility, which was accepted without comment. World War II commenced before the station was completed. Newman was promoted to Commander and assigned to command the Harman facility from when it opened until 1941, when he was replaced as Officer-in-Charge. The station was commissioned into

9408-551: The objective was found to be further inland and an expeditionary force was required. Meanwhile, HMAS Australia was tasked with scouring the Pacific Ocean for the German squadron. The Australian Naval and Military Expeditionary Force (ANMEF) began recruiting on the same day that the taskforce arrived in New Britain , and consisted of two battalions: one of 1,000 men, and the other with 500 serving and former seamen. On 19 August,

9520-581: The permanent forces, compared to the RAAF's 26.6% and the Army's 15.3%. Throughout the 2022-23 financial year 1,141 enlisted in the RAN on a permanent basis while 1,354 left, representing a net loss of 213 personnel.                The following are some of the current senior Royal Australian Navy officers: Commissioned officers of the Australian Navy have pay grades ranging from S-1 to O-10. The highest rank achievable in

9632-494: The position of an enemy transmitter has been invaluable since World War I , and it played a key role in World War II 's Battle of the Atlantic . It is estimated that the UK's advanced " huff-duff " systems were directly or indirectly responsible for 24% of all U-boats sunk during the war. Modern systems often use phased array antennas to allow rapid beam forming for highly accurate results. These are generally integrated into

9744-402: The radio waves could be arriving. This is called a null in the signal, and it is used instead of the strongest signal direction, because small angular deflections of the loop aerial away from its null positions produce much more abrupt changes in received current than similar directional changes around the loop's strongest signal orientation. Since the null direction gives a clearer indication of

9856-473: The received signal: The difference in electrical phase along the rim of the loop at any instant causes a difference in the voltages induced on either side of the loop. Turning the plane of the loop to "face" the signal so that the arriving phases are identical around the entire rim will not induce any current flow in the loop. So simply turning the antenna to produce a minimum in the desired signal will establish two possible directions (front and back) from which

9968-677: The same. Principal Chaplains and MSWOs, however, have gold braid on the peak of their white service cap. From January 2021, MSWOs and all chaplains wear the branch's new non-faith-specific rank insignia of a fouled anchor overlaying a compass rose, which represents a united team front, encompassing all faiths and purpose. Chaplains and MSWOs have insignia that reflect their religion on collar mounted patches (Cross for Christian, Crescent for Muslim etc, Compass rose for MSWOs.) The RAN currently operates nearly 50 commissioned vessels, made up of nine ship classes and three individual ships, plus 11 non-commissioned vessels. In addition, DMS Maritime operates

10080-426: The signal direction – the null is "sharper" than the max – with loop aerial the null direction is used to locate a signal source. A "sense antenna" is used to resolve the two direction possibilities; the sense aerial is a non-directional antenna configured to have the same sensitivity as the loop aerial. By adding the steady signal from the sense aerial to the alternating signal from the loop signal as it rotates, there

10192-401: The signal using PLL, the direction to the broadcaster can be continuously displayed. Operation consists solely of tuning in the station, and is so automatic that these systems are normally referred to as automatic direction finder . Other systems have been developed where more accuracy is required. Pseudo-doppler radio direction finder systems use a series of small dipole antennas arranged in

10304-466: The site, forming the new suburb of Lawson . Harman residents get preference for a shared Priority Enrollment Area (PEA) of Forrest Primary and Red Hill Primary, Telopea Park School for high school, and the Narrabundah College . Royal Australian Navy The Royal Australian Navy ( RAN ) is the naval branch of the Australian Defence Force (ADF). The professional head of the RAN

10416-402: The size of the receiver antennas are a function of the wavelength of the signal; very long wavelengths (low frequencies) require very large antennas, and are generally used only on ground-based systems. These wavelengths are nevertheless very useful for marine navigation as they can travel very long distances and "over the horizon", which is valuable for ships when the line-of-sight may be only

10528-650: The station's identifier that is used to confirm the station and its operational status. Since these radio signals are broadcast in all directions (omnidirectional) during the day, the signal itself does not include direction information, and these beacons are therefore referred to as non-directional beacons , or NDBs . As the commercial medium wave broadcast band lies within the frequency capability of most RDF units, these stations and their transmitters can also be used for navigational fixes. While these commercial radio stations can be useful due to their high power and location near major cities, there may be several miles between

10640-505: The turn of the 20th century. Prominent examples were patented by John Stone Stone in 1902 (U.S. Patent 716,134) and Lee de Forest in 1904 (U.S. Patent 771,819), among many other examples. By the early 1900s, many experimenters were looking for ways to use this concept for locating the position of a transmitter. Early radio systems generally used medium wave and longwave signals. Longwave in particular had good long-distance transmission characteristics due to their limited interaction with

10752-501: The two. The pseudo-doppler technique is a phase based DF method that produces a bearing estimate on the received signal by measuring the doppler shift induced on the signal by sampling around the elements of a circular array. The original method used a single antenna that physically moved in a circle but the modern approach uses a multi-antenna circular array with each antenna sampled in succession. The Watson-Watt technique uses two antenna pairs to perform an amplitude comparison on

10864-498: The war. Modern systems often used phased array antennas to allow rapid beamforming for highly accurate results, and are part of a larger electronic warfare suite. Early radio direction finders used mechanically rotated antennas that compared signal strengths, and several electronic versions of the same concept followed. Modern systems use the comparison of phase or doppler techniques which are generally simpler to automate. Early British radar sets were referred to as RDF, which

10976-457: The wavelength, more commonly 1 ⁄ 2 – the half-wave dipole is a very common design. For longwave use, this resulted in loop antennas tens of feet on a side, often with more than one loop connected together to improve the signal. Another solution to this problem was developed by the Marconi company in 1905. This consisted of a number of horizontal wires or rods arranged to point outward from

11088-400: Was a sub-unit that maintained the corresponding HF and low frequency (LF) transmitting equipment, including the three 600 feet (180 m) masts for the 250kW, 44kHz transmitter. The station was equipped with 40kW and 10kW HF transmitters that used a variety of antennas including rhombic, vertical monopole, and log-periodic antennas. The station was initially built with small cottages flanking

11200-603: Was commissioned into the RAN as a stone frigate in 1943. In addition to its communications and logistics roles, the base hosts reserve units from both the Australian Army Reserves and Royal Australian Air Force Reserves, as well as cadet units from all three branches of the Australian Defence Force Cadets . The base is also reported to be a major contributor to the U.S. National Security Agency 's XKeyscore surveillance program. The commander of

11312-457: Was equipped with a direction finder (Appleyard 1988). Very few maritime radio navigation beacons remain active today (2008) as ships have abandoned navigation via RDF in favor of GPS navigation. In the United Kingdom a radio direction finding service is available on 121.5 MHz and 243.0 MHz to aircraft pilots who are in distress or are experiencing difficulties. The service is based on

11424-495: Was expanded significantly and at its height the RAN was the fourth-largest navy in the world, with 39,650 personnel operating 337 warships, but no active submarines. A total of 34 vessels were lost during the war, including three cruisers and four destroyers. After the Second World War, the size of the RAN was again reduced, but it gained new capabilities with the acquisition of two aircraft carriers, Sydney and Melbourne . The RAN saw action in many Cold War –era conflicts in

11536-532: Was expended on identifying secret transmitters in the United Kingdom (UK) by direction finding. The work was undertaken by the Radio Security Service (RSS also MI8). Initially three U Adcock HF DF stations were set up in 1939 by the General Post Office. With the declaration of war, MI5 and RSS developed this into a larger network. One of the problems with providing coverage of an area the size of

11648-791: Was formed with members of the Royal Australian Naval Reserve who could not find billets in the RAN. Following the entrance of the Ottoman Empire in alliance with the Central Powers, HMAS AE2 was committed to the initial naval operation of the Gallipoli campaign . After the failure of the naval strategy, an amphibious assault was planned to enable the Allies' warships to pass through the Dardanelles and capture Constantinople . The RANBT

11760-521: Was initially a green-water navy , as the Royal Navy provided a blue-water force to the Australian Squadron , which the Australian and New Zealand governments helped to fund; the squadron was assigned to the Australia Station . This period lasted until 1913, when naval ships purchased from Britain arrived, although the British Admiralty continued to provide blue-water defence capability in

11872-573: Was largely supplanted in North America by the development of LORAN in the 1970s. Today many NDBs have been decommissioned in favor of faster and far more accurate GPS navigational systems. However the low cost of ADF and RDF systems, and the continued existence of AM broadcast stations (as well as navigational beacons in countries outside North America) has allowed these devices to continue to function, primarily for use in small boats, as an adjunct or backup to GPS. In World War II considerable effort

11984-401: Was once the primary aviation navigational aid. ( Range and Direction Finding was the abbreviation used to describe the predecessor to radar . ) Beacons were used to mark "airways" intersections and to define departure and approach procedures. Since the signal transmitted contains no information about bearing or distance, these beacons are referred to as non-directional beacons , or NDB in

12096-419: Was previously made up of seven Force Element Groups , but after the New Generation Navy changes, this was restructured into four Force Commands: The Royal Australian Navy consists of over 50 commissioned vessels and over 16,000 personnel. Ships commissioned into the RAN are given the prefix HMAS ( His/Her Majesty's Australian Ship ). The RAN has two primary bases for its fleet: the first, Fleet Base East ,

12208-573: Was projected; together with significantly more data than was originally estimated. About 2.5 kilometres (1.6 mi) southwest of the main complex was the Bonshaw Receiving Station, in which watchkeepers listened for messages from ships on the high frequency (HF) bands. This area was designated as a radio quiet zone. About 20 kilometres (12 mi) north-west of Harman , the Belconnen Naval Transmitting Station

12320-637: Was sent ashore, along with the invasion, for engineering duties. Later in the war, most of the RAN's major ships operated as part of Royal Navy forces in the Mediterranean and North Seas, and then later in the Adriatic, and then the Black Sea following the surrender of the Ottoman Empire . In 1919, the RAN received a force of six destroyers, three sloops and six submarines from the Royal Navy, but throughout

12432-455: Was symmetrical, and thus identified both the correct degree heading marked on the radio's compass rose as well as its 180-degree opposite. While this information provided a baseline from the station to the ship or aircraft, the navigator still needed to know beforehand if he was to the east or west of the station in order to avoid plotting a course 180-degrees in the wrong direction. By taking bearings to two or more broadcast stations and plotting

12544-535: Was to deprive the Imperial German Navy 's East Asia Squadron of regional intelligence by removing their access to wireless stations. On 11 August, three destroyers and HMAS Sydney prepared to engage the squadron at German Anchorages in New Guinea, which did not eventuate as the vessels were not present. Landing parties were placed on Rabaul and Herbertshohe to destroy its German wireless station; however,

#484515