Q1a A. Skywave 2 – 3 Mhz if prior to sunrise 3 – 6 Mhz if after sunrise B. Skywave 5 – 10 Mhz C. Groundwave/Skywave 2 – 4 Mhz full range prior to and after sunset although would bias towards 4Mhz before sunset and towards 2Mhz after sunset. Would also utilise higher power levels whilst using groundwave, although for a voice circuit skywave would easily be achieved utilising only 40 watts of power. D. Skywave 2 – 4 Mhz E. Groundwave/Skywave 2 – 4 Mhz full range prior to and after sunrise although would bias towards 2Mhz before sunrise and towards 4Mhz after sunrise. Would also utilise higher power levels whilst using groundwave, although for a voice circuit skywave would easily be achieved utilising only 40 watts of …show more content…
VLF is far better for a submarine, operationally, if only able to come close to the surface without actually surfacing. The transmission of ELF/VLF requires antennas of great lengths, therefore impossible to install on a submarine. If a submarine is required to transmit, it must deploy an aerial to the ocean surface, or actually surface to utilise one of its fixed asset aerials for communication using HF/UHF or VHF). Q2b The use of “burst transmissions” is usually conducted using HF (3-30MHz)/VHF (30-300MHz)/UHF (300-3000MHz)/SHF (3-30GHz), and involves either the deployment of a buoyant trailed wire antenna or the submarine actually having to come to the surface to utilise on of its extendable whip antenna or other fixed antenna. The actual transmission, usually contains a massive amount of data but with a very short transmission time. Due to the larger than normal amount of data the transmission is of a greater bandwidth, therefore more susceptible to scanning and eventually Direction Finding, to alleviate this, frequency hopping is used. Q3 The difficulties that would be encountered with an aircraft approaching the UK. Initially, the obvious one, with the aircraft closing the UK, it would constantly reduce the distance between the aircraft and the Transmit/Receive aerials, which would need a reductions in frequency the closer the aircraft got. This would not be a problem
Click here to unlock this and over one million essaysGet Access
This separation presented communication and data-sharing challenges. Furthermore, the new design contained a number of technical risks, one of them was designing a submarine that would operate in a manner and environment very different from what Kockums was accustomed to. The risk resulted fuel system has been proven to be problematic. Swedish submarines have short patrols in calm, relatively fresh water. When a similar design was used in the salty, open water in which Australian submarines operate, water was sucked into the engine causing failure. Moreover, the RAN submarines transit greater distance and are on station for months at time, which has number of implications for fuel storage, hotel service, and other hull design features. The difference in operation concept and environment ultimately led to some equipment and system decision during design that caused problems with operations and supportability.
We will be able to maintain vessel operation with only a few crew members. Special combat forces equipped with this type of submarine can carry out the task of protecting important structures. Small submarines can conduct a variety of activities such as: Destroying the enemy's sea lanes; Transporting landing forces on the island; Reconnaissance, neutralization of minefields and bombardment; Sabotage of port facilities and other important objectives. It is in line with the traditional Vietnamese military guerrilla
Module 9: Briefly describe basic procedures in using the radio: call-up, acknowledgement, length of broadcast, etc.
Submarines are basically a watercraft cable of independent operation under water.It is different from a submersible that has more limited underwater capability. Beginning in ancient times, humans sought to operate under water. From simple submersibles to nuclear-powered underwater behemoths, people have searched for a means to remain safely underwater to gain the advantage in warfare, resulting in the development of the submarine. It was first built in 1620. Today's attack and ballistic submarines are made from special steel and/or titanium that are needed to withstand the pressures of the 1,000' depths at which they operate. US submarines use a hi-pressure, flexible steel known as HY-100, while the Russian boats are made from very expensive titanium.
A submarine is defined as “something that functions or operates underwater; specifically: a naval vessel designed to operate underwater.” This definition holds true today but started at the beginning of the Civil War when submarines originally became a popular choice of weaponry. In general, submarine crews were composed of a commander, who steered the boat, and six or more men who used hand cranks to move the boat. Many inventors intended on creating electric motors to move the boat, but they were unable to produce enough torque. Submarines were primarily used in combat because they could travel invisibly. Innovations like submarines did not just change the way people fought wars–they also changed the way people lived.
Transmission interferences: Weather, terrain, and the range from the nearest signal point can all interfere with signal reception. Reception in tunnels, some buildings, and rural areas is often poor.
Strathfield group limited trading as Strathfield Car Radio, is one of successful electronics retailer’s 96 outlets in Australia (Sharma & Sainsbury, 2009). Their mission involves to express a passion for products of mobile, office, motors, home entertainment, accessories, network provider carriers and installation. They have extensively been involved car stereo and security system market.
The Collins Class submarine was prone to excessive noise signatures whilst travelling at speed and lacked the operational capability to enter conflict situations due to the
When the military developed the ability of flight they had to rethink the communication issues of ground to air and air to air. They started with ground to air communication. This began with the pilots having to to land to send and receive messages. Later on the military developed black and white strips to communicate with aircraft in the air. These stripes would be laid out in a prearranged pattern to relay a message to the pilot. These were the only methods of communication with aircraft for a long period of time. It wasn’t until very high frequencies and
Communications are carried by waves. One type of communication is AM and FM radio. AM and FM radio’s use radio waves. A radio wave is an electromagnetic wave propagated by an antenna at various frequencies. In AM (amplitude modulated) radio waves, the audio signal changes the amplitude of the carrier wave. In FM (frequency modulated) radio waves, the audio signal changes the frequency of the carrier wave. Australia’s broadcast bandwidth for AM radio is 500-1500 KHz and for FM radio it is 80-108 MHz. AM radio waves can be affected by electrical interference (such as household appliances) and devices oscillating in the same frequency band. FM radio waves aren’t subject to