Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Phase VI Study Cards > CANTASS > Flashcards

CANTASS Flashcards

1
Q

What is the purpose of CANTASS

A

To provide HMCS STJ with a passive underwater sensos for the detection, localization and classification of subsurface and surface targets.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the details of the array group?

A

The array is 865 feet long with a 75 foot drogue line attached. The drogue provides stability when the array is launched. There is also a 5600 foot tow cable, 300 feet of which is left on the drum to keep everything secure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the make up of the modules?

A

The tail consists of 20, 40 foot modules mad up of a rubber coating, coaxial cable and a steel wire. The modules are filled with ISOPAR-M for buoyancy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What types of modules are there?

A

1) HDTM - Heading Depth and temperature module
2) Telemetry Drive Module (TDM)
3) Vibration Isolation Module (VIM)
4) Very Low Frequency Module (VLFM x 8)
5) Low Frequency Modules (LFM x 4)
6) Medium Frequency Modules ( MFM x 2)
7) High Frequency Modules (HFM x 2)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the purpose of the Stowage and Handling Group?

A

The Stowage and Handling Group is used to deploy, retrieve and store the array. Components are located in the Towed Array Equipment Room

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the purpose of the fairlead?

A

The fairlead is an opening through which the CANTASS is deployed. There is a plug placed when deployed to reduce vibration, a wiper for cleaning and a freshwater outlet for lubrication.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the purpose of the handling drum?

A

The handling drum is used to temporarily store the array for maintenance including module replacement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the purpose of the level wind?

A

The level wind guides the array onto the stowage drum. The level wind can be moved automatically, manually and in emergency mode.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the purpose of the stowage drum?

A

The stowage drum is where the array and tow cable are stored upon retrieval.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the purpose of the winch?

A

The winch assembly includes a 40hp motor and is used to launch and recover the array. There is a pawl and lock assembly used to keep the array locked in place once it is paid out.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the purpose of the control console?

A

The control console is the HMI for controlling the stowage and handling group. The winch and level wind can be controlled and monitored here when deploying and retrieving.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the purpose of the array receiver?

A

The array receiver
1) Distributes power and control signals to the array
2) Receives acoustic data from the array
3) Receives cable scope and interlock signals from the stowage and handling group.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the purpose of the high speed signal processor?

A

The HSSP processed the acoustic data received from the array receiver and interfaces them to the DMDU. It performs FFT’s for spectral analysis, beamforming for target localization and integration for noise reduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the purpose of the Data Management and Distribution Unit?

A

The DMDU is used for control, operation and diagnostics of the array. It is broken into four sub-components.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the DMDU sub-components?

A

1) System Controller
2) Tracking Processor
3) Display Processor
4) Mass Memory Unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the purpose of the system controller?

A

Control and health monitoring of the DMDU, interface with CMS, HSSP and the maintenance console. It also converts digital audio signals to analog for listening.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the purpose of the tracking processor?

A

This processor takes detections from the HSSP and monitors over time to provide tracks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the purpose of the Display Processor?

A

It provides the interface to the display consoles, generating video data and interpreting operator inputs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the purpose of the mass memory unit?

A

The mass memory unit is used to store acoustic and spectral data. It has a 30 minute UPS to maintain data storage, facilitating a quicker boot up time if power is lost.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What components make up the Data Services Rack?

A

1) High Density Digital Recorder
2) Audio Panel
3) Control Panel
4) UPS for the Data Management and Distribution Unit
5) Maintenance Console

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the purpose of the Audio Panel in the Data Services Rack?

A

It is a headset jack that allows operator to listen to received and recorded audio signals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the purpose of the Control Panel in the Data Services Rack.

A

The control panel is used to power the system up and down.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the purpose of the High Density Digital Recorder in the Data Services Rack?

A

This is a magnetic tape recorder that stores unprocessed audio data. This can be used in replay and send ashore for further processing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the purpose of the maintenance console int he data services rack.

A

This is a maintenance laptop kept in the AFT SIS and connected to the Data Management and Distribution Unit. It allows technician to perform diagnostics, maintenance and software uploads.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Within the Display Control Group, what is the purpose of the display console assembly.

A

This is two green displays, an audio jack, joystick a keyboard. This is the main HMI for CANTASS.

27
Q

Within the Display Control Group, what is the purpose of the CANTASS control rack.

A

This rack is located between the two consoles. It contains a video printer for printing displays, a video switch for selecting which display the printer connects to, a headset jack and an interface for powering the system.

28
Q

What are the CANTASS modes of operation?

A

1) Array - normal mode, the Digital processing group is provided with data from the array receiver.
2) Playback - The Digital Processing Group is given data to process from the High Density Digital Recorder
3) Diagnostics - Technicians are using the maintenance console for maintenance and fault finding.

29
Q

What parameters did you set up for your functional description?

A

1) Operating in array mode
2) 3000 feet of cable scope
3) Underwater vessel is creating noise.

30
Q

What are the CANTASS system interfaces?

A

1) EPG & D
2) HVAC
3) CMS via I/O processor 1
4) Bridge status panel to indicate is CANTASS is in or out.

31
Q

What are the CANTASS redundancy and survivability considerations?

A

1) 30 minute UPS preserves the main memory unit to allow for faster reboots.
2) Emergency motor allows for recovery if main motor fails
3) Level wind can be moved manually using a drill
4) Functions independent of CMS
5) Two display consoles
6) Shared HMS hardware

32
Q

What are the test and trial considerations for CANTASS?

A

1) BITs
2) FITs
3) Sea Water short circuit to test for ingress of water into tail
4) HATs and SATs conducted by UWSE

33
Q

How do the modules connect together?

A

Using locking tab screws.

34
Q

Do you know how the FITS module is fitted?

A

The array is placed on the handling drum where the faulty module is. The array is disconnected and installed the next module up from where the suspected faulty one is.

35
Q

How do we use FITS to determine if the suspected module is actually faulted?

A

When the FITs is in place, there is a dial which tells FITs which module it is mimicking. If the fault disappears, we can deduce that the suspected faulty module was actually faulty.

36
Q

What is the procedure for deploying CANTASS and NIXIE at the same time.

A

CANTASS deployed first. When retrieving, being NIXIE in first.

37
Q

What is the procedure for deploying CANTASS?

A

1) A pipe will be made for the crew to close up.
2) Crew establishes contact with the bridge and reports closed up.
3) There is a narrative used (kept at the control console) detailing the current course, speed, sea state, etc which is read to and confirmed by the technician.
4) Crew sup asks for permission to deploy, if given, they do so until 500 feed of cable scope at which point the ship is no longer in RAM.
5) Every 500 feet or so, the crew sup updates the bridge.
6) Once the ordered cable scope is reached, the crew sup reports to the bridge and asks permission to set the tow point and secure.

38
Q

What safety equipment is needed to pay out the array?

A

Face shield, apron, rubber gloves.

39
Q

What are the two common reasons we would have to cut the tail?

A

If it gets knotted up or if the pawl fails and it gets paid out completely.

40
Q

What preparations are needed prior to cutting the tail?

A

1) We need a GPS fix
2) We can leave a buoy attached or use a sonobuoy to mark the location.

41
Q

Why do we use a pawl?

A

The pawl is a lever that is used to interact with the gear wheel on the winch. It keeps the winch from paying the array out further in response to the tension created by the deployed array.

42
Q

How many people do you need to deploy CANTASS?

A

In reality? Two. The book answer is four.

43
Q

How do you cut the tail?

A

We use the guillotine. We place it on the cable and place the hand pump outside the space. We actuate the hand pump until the cable is cut.

44
Q

Why use the FFT?

A

FFT is used to convert a time domain signal to a frequency domain signal. A frequency domain signal is easier to analyze than a time domain/analog signal. Operators can identify frequencies in a wave and compare them to their database for target classification.

45
Q

What is a weakness of CANTASS?

A

With CANTASS you can’t really get range or speed because there is no reference point for the received sound.

There is also the concept of bearing ambiguity. Bearing can be determined, but you won’t know if it is on the left or right side of the array and you may get two tracks. This can be solved by changing course to determine which is a false track.

46
Q

Explain DEMON analysis

A

Detection of Envelope Modulation of Noise.

It is a technique used to identify and classify sound sources.

Since the machinery and propellors of ships make distinct sounds, DEMON analysis is used to extract information about the sound source.

DEMON analysis demodulates the sound to pick out the sounds of engines, propellors, etc.

An FFT is applied to convert the signal into the frequency domain for analysis. By analyzing the frequency components, useful information can be gleaned from the sound source.

47
Q

Define the spacing of the hydrophones?

A

The spacing of the hydrophones determines the beam pattern of the array. As wavelength/distance between the hydrophones decreases, the number of beams increases.

48
Q

How does CANTASS differentiate between frequencies?

A

CANTAS operators determine which set of frequencies they are interested in.

49
Q

What are the limits on streaming CANTASS?

A

1) Within 500 feet of cable scope, the ship is in RAM
2) Retrievals should take place between 10-15 knots
3) See NAVORD 3137-1 for details

50
Q

What data is sent to SONAR ops via CMS?

A

1) Cable deployed
2) Cable scope
3) Array depth

51
Q

Can CMS send any instructions to CANTASS?

A

No

52
Q

What is Target Motion Analysis used for?

A

This can be used to determine the range to a target by using acoustic data from multiple reference points using other units or maneuvering our ship.

53
Q

What is the range of CANTASS?

A

The ideal range is 18-20 NM.

54
Q

Are environmental conditions the only thing affecting the range of CANTASS?

A

No, self noise, ambient noise and target noise also have an impact.

55
Q

How does CANTASS use beamforming?

A

CANTASS can determine the direction of a contact by summing the acoustic data of adjacent hydrophones with the appropriate phase delay.

56
Q

What is the physical connection between the CANTASS and the array receiver?

A

There is a slip ring assembly connected to the array receiver.

57
Q

What are some shortcomings of CANTASS?

A

1) Unable to detect range
2) Need another reference point to determine the unambiguous bearing of a target
3) CANTASS use is limited by the ship speed as self noise will reduce its effectiveness.

58
Q

What is TMA?

A

TMA is Target Motion Analysis. CANTASS will show two targets on either side. When you move the ship, you get one target that remains for real, and another than should prove false.

59
Q

What is Manchester Encoding?

A

1) A Binary 0 is represented by a high to low transition
2) A binary 1 is represented by a low to high transition.
3) Clock and data combined into a single signal
4) This type of encoding provides for a balanced, DC signal more immune to EMI and therefore will experience fewer losses over a long run.

60
Q

What is the passive SONAR equation?

A

TS - TL +DI-NL > DT

61
Q

Are there sea state restrictions for deploying CANTASS?

A

5+

62
Q

What is the minimum water depth?

A

50 meters

63
Q

Why would we raise or lower the array?

A

To put it in an appropriate sound channel?

64
Q
A

Phase VI Study Cards (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions