RADAR Suite Flashcards
What is the purpose of the radar suite?
To provide STJ with the ability to detect and track air and surface targets to help build the recognized maritime picture and aid in the TEWA process.
What does SMART-S stand for?
Signaal Multibeam Acquisition RADAR for Tracking S-Band
What is the purpose of the 3D radar?
To provide STJ with a long-range surveillance capability to detect, localize and track air and surface targets.
Within the antenna assembly, what is the purpose of the antenna array pack
The antenna array pack is 16 linear arrays sensitive over the entire elevation coverage. They are vertically polarized and connected to their respective TR books.
What is the purpose of the TR books?
The TR books are for transmit and receive. Each book can amplify the RF to 1150W. When transmitting, phase shifting is used to shape and direct the beam. When receiving, the received signals are amplified and distributed to one of the four boards in the Multi-Channel Receiver.
What is the purpose of the multi-channel receiver?
The MCR down converts the received signal to an IF and extract the In-Phase and Quadrature phase data for processing.
What is the purpose of the Radar Signal Generator?
The RSG generates the RF signal for the TR books and the MCR.
What is the the purpose of the 3D IFF antenna?
This antenna transmits the RF signals used by the IFF system to identify air contacts.
What is the purpose of the 3D Pedestal?
The pedestal contains the direct drive motor - responsible to control the rotation of the antenna and the Rotary Joint Unit, which connects the above and below deck components.
What is the purpose of the Drive Control and Cooling Cabinet?
The DCCC provides filtering and control commands to the Direct Drive Motor. The cooling side receives chilled water from the ships supply which is used in the liquid to liquid heat exchanger for the TR books.
What is the purpose of the dry air unit?
The DAU supplies dry air to the antenna, DCCC and SPC to keep out moisture and debris.
What is the purpose of the maintainers terminal?
The maintainers terminal is used for local control, maintenance and software uploads.
Which three sub-components make up the SMART S Processing Cabinet (SPC)?
1) Signal processing Unit
2) Data Processing Unit
3) Gateway BIT and Control
What is the purpose of the Signal Processing Unit?
The SPU is responsible for:
1) Beamforming
2) Digital Pulse Compression
3) Doppler Filtering
4) Detection
What is the beamforming used for?
1) On transmit the beamforming is used to send the transmission at a desired elevation.
2) On reception, beamforming is used to determine the elevation of a target.
What is the purpose of digital pulse compression?
To match the receive signal with the bandwidth of the receiver.
What is the purpose of doppler filtering?
It is used to identify targets based on their velocity relative to the radar system.
Tell me about detection?
Detection involves sampling of the returns to determine if they exceed the noise threshold and are determined legitimate targets.
What is the purpose of the Data Processing Unit?
The DPU provides the extraction and tracking functions for air, surface and jamming surveillance.
What is the purpose of the Gateway BIT and Control?
This subcomponent allows the system to interface with CMS, NDDS and the maintainer terminal.
What are the modes of operation for 3d?
1) Defense mode
2) Surveillance Mode
Tell me about defense mode.
In defense mode, the antenna is rotating at 27rpm with a wide bean elevation coverage and a range of 83NM
Tell me about surveillance mode.
Surveillance mode has a rotation speed of 13.5 RPM with a narrow elevation beam and a range of 135RPM.
What is the purpose of the Interrogate Friend or Foe?
To provide STJ with the ability to identify aircraft and other military ships. This is used to help build the recognized maritime picture.
What is the purpose of the IFF equipment rack?
The IFF equipment rack communicated with the transponder and interrogator antennas. It processes replies and interrogations and interfaces with CMS.
In the IFF equipment rack, what is the purpose of the control box?
The control box distributes ship power, interfaces with the aloft switch and tracks parent radar status.
What is the purpose of the mission/IFF system computer?
The M/ISC provides the interface to CMS and monitors for system faults.
What is the purpose of the Transponder?
The transponder takes interrogations received by the transponder antennas, processes them and sends replies. Some replies require KIV-77 crypto.
What is the purpose of the Interrogator?
The interrogator initiates challenges using a 4kW solid state amplifier, and sends it through the appropriate interrogation antenna. Replies are processed, information is extracted to identify target.
What is IFF mode 1?
Mode 1 is a military mode that provides a two digit code to identify aircraft.
What is IFF Mode 2?
Mode 2 is a military mode where a a four digit tail number code is sent.
What is Mode 3 IFF?
Mode 3 is a civilian or military IFF mode. A four digit squawk code is sent to identify aircraft.
What is mode 4 IFF?
Mode 4 is a military mode where encrypted challenges and replies are sent.
What is mode 5 IFF?
Mode 5 is a military mode where an encrypted 24 BIT identification address is sent that includes GPS data.
What is Mode C IFF?
Mode C is a civilian or military mode where altitude information is sent.
What is Mode S IFF?
Mode S is a civilian or military mode where a 24 bit identification address is sent which also includes altitude.
What is the purpose of SG AMB?
To provide STJ with accurate 3D tracking of air and surface targets.
What components make up the antenna assembly?
1) 18 Antenna Array Elements
2) Turntable
3) Rotary Joint
4) External Cooling Fan
5) Air Filter Unit
Explain the function of the 3D antenna assembly
Filtered air is supplied to the ECF which circulates through the assembly to prevent moisture build up.
The turntable receives commands from the antenna control unit through the rotary joint to move the antenna in azimuth and park it when needed.
The 18 antenna array elements shape and transmit energy into the medium at a desired elevation and shape the receive signals to find the target elevation.
What is the purpose of the antenna control unit?
The ACU interfaces control signals from the Signal and Data Unit to the turntable to move, slow and park the antenna in azimuth.
What is the purpose of the transmit and receive unit?
The transmitter uses a travelling wave tube and pulsing exciter circuits to amplify the signal sent from the Radio Frequency Generator to a maximum of 60kW.
Inside the receiver optical receiver cards convert received signals to an intermediate frequency before sending the data to the Signal and Data unit for further processing.
What is the purpose of the Power Distribution unit and Transformer?
The PDU takes ship supply power including 115V 60 and 400 Hz and 440V and distributes to the transformer and sub components.
The transformer rectifies input power to required levels and distributes to the sub components.
What is the purpose of the Signal and Data Unit?
The SDU processes received signals and separates targets from clutter, converts into plots and passes the data to the data processing unit where targets are plotted as surface or air and passed through CMS.
What is the purpose of the cooling unit?
The cooling unit takes chilled water from the ship and uses it in the liquid to liquid transmitter cooler.
What is normal SG AMB mode
It is the default mode where you continuously transmit and gather returns.
What is passive mode w=in SG AMB?
There is no RF TX and you’re passively listening for returns.
What is sector mode in SG AMB?
Transmission is only permitted in certain sectors.
What is intermittent mode with SG AMB?
It is similar to sector mode but the transmitting sectors are selected at random.
What is low probability of intercept mode?
We use it to minimize the radar signature of the ship. The TWT is bypassed and two solid state 10 and 1 watt amplifiers are used.
What is surface mode in SG AMB?
Surface mode reserves one of the 18 arrays to transmit a surface beam to detect a sea skimmer.
What is ducting in SG AMB?
You’re using the atmosphere layers as a duct to transmit and increase your range.
What is the purpose of the Navigation radars
To provide STJ with a high resolution, short range radar to aid in safe navigation.
Explain the nav radar antenna pedestals
The antennas are located on the bridge top and mast. They are belt driven for rotation with performance monitors to test system function. X and S are 8 foot and 12 foot to account for the operating bandwidth.
What is the purpose of Modulated Transmitter Receivers
The X band MTR contains a 25 kW transmitter with a coaxial RF output while the S band is a 30 kW with a waveguide output. They both use a magnetron as an amplifier and energy is coupled to the antenna using a circulator. Inside the receiver, the signal is amplified and converted to a 60MHz IF, processed and sent to each console as a video signal.
What is the purpose if the inter-switch unit?
The ISU interfaces each radar to each MTR, enabling an operator to select which feed they observe at each console.
What is the purpose of the radar consoles?
The consoles are the HMI and KVM for the system. All external interfaces including CMS, SHINNADS and NDDS are connected via the consoles.
What are the NAV radar modes of operation?
1) Normal - either console is fed from either MTR
2) Emergency - the ISU is down and each radar feeds its default console.
What are the radar suite interfaces?
1) EPG+D
2) CMS
3) NDDS
4) HVAC
5) SLA-10
What are the redundancy considerations for the suite?
1) Geographic Separation of each system (except IFF and 3D)
2) Overlap ranges
3) Battle shorts
4) Duplicates
What are the safety considerations for the suite?
1) Electrical
2) RADHAZ
3) HAZMAT
What are the test and trials considerations for the suite?
1) System specific testing through system/maintainer terminals
2) HAT/SAT conducted by SEWE/SAAB/LMC
3) CSAV/STA conducted by SEWE, AWSE, CCS ENG
WRT to IFF what is defruiting
Process of filtering replies from contacts generated in response to another units interrogations
What is black IFF?
1) Radar transmitter off
2) System rotating to provide trigger pulse
3) IFF interrogators transmit
What type of pulse compression does SMART-S use?
Digital pulse compression using Finite Impulse Response Filters
Define Positive Control
Positive control is completed as per the positive control checklists in SEMS S09. Ships, through the CSEO and ultimately the CO can amend the checklists IAW their ship emitter configuration.
Define normal control
Normal control is conducted IAW the checklists. For normal control, keys are removed and kept in the RF emitter keyboard.
Where are the radar blind arcs?
1) SG AMB - forward of the radar because it is behind the mast.
2) SMART-S - aft of the radar due to its position forward of the mast.
3) S-Band aft due its location forward of the mast
4) X-band - slightly aft due to its position on the port yard arm.
What is ducting?
Ducting is a layer of warm air trapped between two cool layers. Radar signals can bounce between the layers extending the range. It cannot be predicted as it is random.
What is the tactical purpose of LPI?
Reduce radar signature making it difficult for missiles to lock us. We can still see targets that are relatively close, perhaps 20NM or so.
Are IFF interrogators unique? Can they be swapped?
The interrogators in the equipment rack are identical and can be swapped. It doesn’t take long and post swap settings must be updated using the maintainer console.
What is electronic stabilization?
Electronic stabilization phase shifts the beam patterns so that they mimic a level platform. This makes the transmission beam level with the horizon when the ship is moving.
When are X band and S band better?
S band is better for longer range and is better in poor weather. X band has a shorter range but the resolution is much better, particularly as you approach the ship.
What are the LPI mode ranges?
1W - 8-9 NM
10W - 20NM
What are the three dimensions?
Range, bearing, elevation
What is the impact of losing a TR book?
It will degrade the accuracy of altitude measurements fr a contact that reflects RF back to that particular TR book?
What is STA for test and trials?
Sensor Track Alignment
It is a means of measuring misalignment of combat system sensors compared to the FWD CEROS.
Provide a full list of HAZMAT.
SG AMB and Nav radars have beryllium oxide in their amplifiers.
The cooling system in SMART S and SG AMB have a glycol water mixture which is typically hazmat.
How many beams does 3D have?
Tx - 1 2 degree X 70 degree beam
Rx - 12 8 degree vertical beams
What is the operating frequency of 3D?
2.9 - 3.1 GHz (E/F band)
What is the operating frequency for SG AMB?
5.4-5.9 GHZ (C band)
What are the operating frequencies of the navigation radars?
X band - 9.41 +/- 30 MHz
S band 3.05 +/- 10 MHZ
What are the operating frequencies of IFF
Tx @ 1030MHz
Rx @ 1090MHz
How many TR books can you lose before the system is INOP?
You can still function as long as 4 TR books remain.
There are two critical TR books
TR1 - for radar calibration
TR7 - Sensitivity Time Control (Protects the receiver from saturation by nearby contacts)
How many scans are needed to retrieve 3D radar info?
Track initiation occurs after two successive scans.
What are the ranges for the 3D radar?
Surface - 22NM and 45 when ducting
Air - 135 NM
What are the SG AMB ranges?
Air - 180km
Surface - 60 km but 180 with ducting
How many targets can SG AMB handle?
200 air
500 surface
50 jammer
What is blind pilotage?
Navigating my nav radar vice visually.
How does IFF determine friend or foe?
Database and will not respond if foe.
Why is there an S-band minimum range?
Because we cannot tilt the AE
Can you view Nav radar on MFW?
Yes, assuming operator has the proper rights .
Does 3D have restrictions during flying stations.
Yes, it must be inhibited or at a minimum sector blanked in the direction of the flight path.
Can we send tracks to CMS?
Yes, assuming they are hooked on the radar consoles on the bridge.
How does phased array radar work?
It uses multiple elements to form a single beam.
How many sweeps are required to obtain radar picture?
Three
How many fire control window can be generated by the 3D radar?
Up to three defines by the operator.
What are the fire control windows used for?
1) PACs
2) Surface fire control
3) Naval gun fire support vs land targets
What is the maximum nav radar range?
24NM
What is the default IFF mode of operation?
Auto, when a target is within its range it will be interrogated.
What NAV data is sent to Nav radars?
Heading, speed through water, course and position (Through LAN connections)
What is the responsible tracker?
If a track is picked up by two systems, they will be track correlated. CMS will decide which system is providing the better track, and that radar will become the responsible tracker.
What is the responsible tracker priority list?
1) CEROS
2) 3D
3) SG AMB
4) NAV
How does 3D get its NAV feed?
Through CMS
How does 3D provide elevation?
The received signal is processed into 16 beams, each of which is a different elevation. The signal strength of each beam is used to determine the elevation.
Why does S band require more power?
Due to its lower frequency
What is the goal of CSAV?
To ensure all sensors are aligned to allow for data correlation.
Why do we use PWM to move the Smart S?
Allows us to control the rotation speed with on/off cycles and varying the duty cycle.
What supplies the 3D cooling?
2X boost pumps in RR2
