Weapons Electrical Flashcards
WEE
How is power measured?
Watts
How is frequency measured?
Hertz
What is voltage?
Unit of electrical potential. Voltage is the pressure which pushed positive electrons through the circuit.
What sort of voltage currents are there?
Alternating Current or Direct Current
What is a transformer?
A transformer has the ability to step up or step down the voltage of AC. The magnetic fields are manipulated to allow the voltage change.
Why can DC not be put through a transformer?
DC relies on only one magnetic field.
How many contacts can X/S band radars hold?
100 overlayed with AIS contacts
What is the range of X/S band?
0.25 - 40nm
How many ARPA consoles do we have?
2 Bridge and Ops Room
What is the radar op modes?
Presentation, motion and trail
What feeds the RF energy to the antennas of the radars?
Transceivers
What is the SRHCR?
Short-range Helicopter Control Radar
How does the SRHCR work?
The SRHCR uses the Doppler effect by analysing the returned microwaved signal off its desired target and comparing how the objects motion has altered the signal.
What band and type is the SRHCR?
S band doppler radar
What is the SRHCR range?
24nm
Where does the SRHCR feed for display?
Combat Management System
Where is the SRHCR located?
Aft Mast
How does the SRHCR get time stamp information from the interface?
NDDS feeds ships time and attitude data to the interface
What does IFF stand for and what does it do?
Identification Friend or Foe: Helps ships/ operators identify contacts
What is the range of the IFF?
250nm
IFF has a transponder which can respond to interrogations in Mode 5. Describe mode 5?
Mode 5 uses an encrypted code which identifies friendly military units from other contacts.
IFF: Do the interrogator and transponder work independently of each other?
Yes
Describe the interrogator of IFF? What code allows altitude to also be measured?
The IFF interrogator measures the Angle and range of the contact to create a 2 dimensional position. If Mode C is in use a 3D position may be obtained by measuring the altitude.
IFF: Describe Mode 1?
Status of military contact being challenged
IFF: Describe Mode 2
Type of contact being challenged in mode 1
IFF: Describe Mode 3
Civil Contacts (ATC use this)
IFF: Mode C
Be able to identify altitude of aircraft
IFF: Mode 5
Crypto secured response
Where is IFF located?
Central Mast then feeds into Ops Room
What does the electromagnetic (EM) log measure? How?
The EM log measures the speed of flow to determine the distance travelled by the ship. It does this by the preamplifier connecting to the sensor which creates a magnetic field. As the ship moves the voltage of the magnetic field is measured by the reading the sensor coil which feeds to the preamplifier to process the data.
EM Log: how does the pre-amplifier work?
The preamplifier reads the voltage being produced by the flow of water proceeding through the magnetic field. The raw data is then fed to NDDS for display.
What does the doppler log measure?
Speed and distance below transducer
How many echo sounders do we have? What are the Hz of their transducers.
2 echo sounders, 200kHz and 30kHz
how is the echo sounder information processed and displayed?
Depth data received and provided straight to the display panel and NDDS.
How to the echo sounder transducers work?
Transducers convert electrical energy into sound energy and transmit waves towards the seabed.
Where are the echo sounder compartments located?
Aft Main and FWD Aux
What does GPS provide to NDDS?
position, time, velocity and status which is then fed to other systems which need the information. The position time modules receive the GPS signals from satellites.
Where are the position time modules located?
Chart Room/ Aft Radar
Where are the GPS antennas?
1 FWD Mast, 1 AFT Mast
What is SNDS
Ships Navigation Data System
What does SINS do?
receives ships GPS position and velocity data and doppler log velocity from NDDS.
If ship power was to fail what must you do for heading?
Manually select a SINS.
Each SINS system has UPS, how long shall it run for?
30min
Each sins has a remote control display unit next to it?
True
How many steering repeats are on the ship?
6
Each steering repeat receives true heading data from the SINS via the buffer and amplifier. Which steering repeats run off aft sins only?
4 and 6, the rest run off FWD sins.
What gyro steering repeats are in the PODS?
3 and 4
How does SINS transfer power and data?
SINS Junction Boxes located in Gyro Room, CCS and both pod rooms.
What number Steering repeats are on the bridge?
5 and 6
What sensors feed NDDS?
PTM-GPS Units, SINS, MET system, AIS, EM Log, Doppler Log and Echo Sounder
What are your redundancies if you lose an NDDS server (there’s 2 servers)?
They work independently of eachother so if you lose 1 server you will still have full function of the other server.
What mode does NDDS normally operate in?
Normal mode, however there is in internal control unit which allows the graphic display of viewing data.
What will NDDS choose automatically in its normal mode of operation?
Which SINS and GPS unit to use for display
What supplies power to the NDDS units? and how much Hz and what they supply?
400Hz power supply feeds the synchro card
What piece of equipment receives information from the Meteorological systems to then provide data to NDS?
Programmable Translators
What MET systems do we have onboard?
Barometric pressure sensor, humidity sensor, 4 wind anemometers,
What is the unit or measurement for air pressure?
Hectopascal
What is the accuracy of the barometric pressure readings?
.2 -.3
Describe the humidity and temperature sensor?
This sensor is located on the bridge roof. The probe measures both in one. The max temp reading is 50 degrees Celsius.
What does VDR record?
Bridge, Alarms, IPMS, radar outputs, AIS data, autopilot data.
Where is VDR stored?
Data Capsule powered by the data acquisition unit
How does AIS work?
VHF radio signals are exchanged with other ships and tracking stations to allow identification of vessels
