Sonobuoys

Question 1

What is the nomenclature for the buoys?

Answer 1

BT Buoys: AN/SSQ-36B
DIFAR: AN/SSQ-53F/G
DICASS: AN/SSQ-62E/F

Question 2

What can you CFS for a DIFAR buoy?

Answer 2

RF channel, RF pwr (on/off), Life, hydrophone (std DIFAR, shallow omni, calibrated omni), acoustic automatic gain control (fast/slow/off), GPS (Enable/Disable)

Question 3

What can you CFS for a DICASS buoy?

Answer 3

RF channel, RF pwr, audio (ping) frequency, depth, GPS (enable/disable)

Question 4

What radio does CFS work with?

Answer 4

UHF downlink. So if your UHF radio is in secure, you will not be able to CFS your buoys.

Question 5

What are the different passive sonobuoy processing modes?

Answer 5

LOFAR/DIFAR Omni
Directional
Steered Cardioid
Orthogonal Cardioid
Synthetic Omni
DEMON (high or low)

Question 6

LOFAR/DIFAR Omni

Answer 6

provides spectrogram (gram) and automatic line integration (ALI). Bearing info is not produced and parameter tracks are not subject to phase-lock constraints

Question 7

DIFAR Directional

Answer 7

provides gram, ALI, and bearing vs. frequency

Question 8

DIFAR Steered Cardioid (theoretical gains?)

Answer 8

Sonobuoy cardioid is a beam which is formed in the AP using the sonobuoy’s omni, N/S, and E/W channels. The main beam provides a theoretical 4.77 dB gain. The null response provides an approx -10 dB response relative to non-cardioid DIFAR processing.

Question 9

DIFAR Orthogonal Cardioid

Answer 9

Five ALI and gram data sets are produced - one for the omni channel and one for each of the 4 cardioid beams pointing to the cardinal hdgs. The benefit is that there is an assured beam pattern gain regardless of the target bearing, ranging from 4.77 dB best case to a theoretical 3.4 dB worst case (at the 45 of a cardinal hdg)

Question 10

DIFAR Synthetic omni

Answer 10

Provides gram, ALI, and BVF data on a synthetic omni beam

Question 11

How many bins are in a band?

Answer 11

256

Question 12

How many bands per processing option are supported by the AP

Answer 12

16

Question 13

What is Octave Processing?

Answer 13

Constant Percentage Resolution (CPR), provides a logarithmic frequency scale across each octave. The center frequency and width of each bin increases by the same ration (0.27% per bin) across the entire processing range.

Question 14

Full band?

Answer 14

Octaves 1-8

Question 15

Half Band?

Answer 15

Octaves 0-7

Question 16

Quarter band?

Answer 16

Octaves 0-6

Question 17

Eighth band

Answer 17

Octaves 0-5

Question 18

What are Vernier bands?

Answer 18

provide a linear frequency scale covering a fraction of the octave containing the center frequency. Each V4 band covers 1/4 of the octave and each V8 band covers 1/8th of the octave. The width of the band is set based on the octave containing the center frequency.

Question 19

What are Constant Resolution Bands?

Answer 19

CR processing provides a constant bin width across the entire processing range independent of the center frequency. Six CR bands are available, CR4-CR9

Question 20

What are the different gram rate selections?

Answer 20

1.25 seconds, 2.5 seconds, 5 seconds, 10 seconds. Shorter gram time provides improved performance against dynamic frequencies or transient signals. Longer gram time selections provide for a longer total gram history window and improved performance against relatively stable frequencies

Question 21

What does DICASS signal processing produce?

Answer 21

range/bearing and range/Doppler display data

Question 22

DICASS waveforms?

Answer 22

CW-short, CW-medium, CW-long, FM

Question 23

What colors indicate doppler?

Answer 23

Red: up Doppler
Blue: down Doppler
Green: zero Doppler

Question 24

What is Fine Bearing/Frequency function

Answer 24

Measures the frequency and bearing for the highest amplitude signal within +/- 10 frequency bins of the cursor frequency. The measured frequency and bearing are displayed at the top of the sonobuoy Analysis display

Question 25

How many parameter trackers is the AP capable of processing?

Answer 25

8