ALFS

Question 1

What does ALFS stand for

Answer 1

Airborne Low Frequency Sonar

Question 2

What is the nomenclature for the dipping sonar set

Answer 2

AN/AQS-22

Question 3

What does the dipping sonar consist of?

Answer 3

Reel and Cable Assembly
Cable Reeling Machine
Reeling Machine Interface Unit (RMIU)
Reeling Machine Control Unit (RMCU)
Transducer Assembly (TA)
Sonar Transmitter/Receiver (ST/R)

Question 4

How much cable is in the sonar reel and cable assembly?

Answer 4

approx 2550’

Question 5

When do limit sensors open on the reel?

Answer 5

When less than 5-8 wraps of cable remain

Question 6

What are the 6 modes of operation?

Answer 6

Automatic (remote) Hyd
Manual (RMCU) Hyd
Aux Hyd
Aux Electrical
Aux hardware Electric
Hand crank

Question 7

What is the difference between Aux Hyd and Aux Electrical

Answer 7

Aux hyd provides ability to raise/lower TA in the event of a loss of normal function. Aux electric provides ability to raise and lower TA in the event of a loss of hyd power

Question 8

What does the raise speed limiter do?

Answer 8

ensure the raise speed does not exceed a set threshold to ensure a safe approach speed of the TA as it approaches A/C

Question 9

When does the SUBMRG indicator appear?

Answer 9

When the TA is between 28’ and 40’ depth

Question 10

What does the Reeling Machine Interface Unit do?

Answer 10

controls reeling machine functions, regulates smooth transitions of TA dipping activities, and performs the reeling machine BIT. Provides electrical interfaces between components of the dipping sonar system. Works automatically

Question 11

What does the Reeling Machine Control Unit do?

Answer 11

contains operating controls and failure indications for the reeling machine and provides the means for lowering and raising the TA

Question 12

What powers the sonar reeling machine?

Answer 12

the Utility Hyd System

Question 13

What are the requirements for cable angle hover mode engagement?

Answer 13

GS of +/- 5 knots, alt hold within 10’ of selected alt, and dome wet indication

Question 14

What are the different pulse types for the ALFS?

Answer 14

Continuous, Frequency Modulated, Hyperbolic FM, Linear FM, Combo

Question 15

What are clusters?

Answer 15

When a ping receives data that exceeds a signal processing threshold, that data is sent to a cluster filter which then checks to see if that data matches the target-like criteria and then it will compute the bearing and range for each cluster remaining. Clusters are assigned a ping age and will be deleted by the AOP if their ping age exceeds 3.

Question 16

What are sequential detects?

Answer 16

The AP sequential detector receives clusters from cluster processing and identifies those clusters that are more likely to correspond to target-like objects and rejects those more likely to be due to noise. Sequential detects identify clusters that have similar properties and these form sequential detections. Clusters that don’t match the properties of existing sequential detections are used to form possible new sequential detections. After three pings with no live cluster association, the sequential detection will be purged and no longer reported.