Acoustic Systems Trainer-SONAR

Frequently Asked Questions
&
Answers.
(Updated May 2009)

"Can the speed of sound in water be measured at various temperatures?"
Yes, at room temperature and up to 50C, but also below room temp.................. by using ice...'on the rocks'!

"Is the PC/laptop spec demanding?"
Not really.........Windows XP/Vista.....1GHz, 20 Gb hard drive, 2 Gb RAM, USB2 port, color monitor, sound card!
However, the old story..............the faster, the better!  
Note: A USB2 port is required for the current production AST.

"Is the water - salt water or fresh water?"
Either - it's entirely your choice, the difference in results is minor with this water volume.......but the taste is different!

"Give me a list of the test instruments in the Sonar Signal Analyzer please?" 
All two channel-
Oscilloscope, Spectrum Analyzer, Multimeters galore, Transient Recorder, and a
single 'channel' AWG(Arbitrary Waveform Generator with Sweep and Burst..........dozens of features!
Note: A new 4 channel SSA is an option but does not have an AWG!

"Do you supply various profile active targets?"
Three Flat plates, Grill target and a Sphere, but we can consider other shapes on request........within reason!
We also supply 3,4,5 (6 on request) bladed, miniature propellers for passive operation.

"Why is the AST Console so big?"
Safety! This is a 'two student' platform: one to work in the water, and one to operate the controls,
also to make configuration  patching on the panel easier.........and somewhere to set the monitor!
Note: More and more SONAR Instructors use the AST Console for classroom demos.

"What is the Sonar Signal Analyzer sampling rate?"
Variable but 100Ms/sec max (Mega samples per second)........fast enough for SONAR!
 Note: An option is the new 1Gs/sec SSA with a 20MHz AWG

"Can your AST show scattering?"
Acoustic volume scattering? Yes, easily! This is one of the most revealing visuals!

"What is the operational frequency.....................?
It is around 190kHz, but the transducers are refined to perform efficiently at 192kHz..........you can also make them operate at a lower frequency......
......without any changes to the transducer!

"How about underwater communications between....................?"
No problem! We have transmitted Morse, voice, music, and other 'noises' through our 'vast' volume of water!

"Do you have the ability to listen to submersed passive targets?"
Yes, uses specialized software and audio frequency hydrophone!
Note: A Sound Library is also supplied.

"Does the Pulse Width change automatically?"
No, it has to be manually varied, or it can be set to the CAL(calibrated) position, as with the PRF, TX frequency, and Phase parameters.
Variable PW gives a nice demo of target range resolution.

"We are a USA University, Marine Engineering department, is the AST suitable for development work?"
The AST is very well suited to underwater development studies, and it is already installed at Texas A&M University at Galveston.
A degree dissertation using the AST, has been published by the Institute of Marine Studies at the University of Plymouth (UK). Contact us for a copy-
info@itp101.com

"Is there a development version of the system suitable for research work?"
 See the A.U.D.I. Acoustic Underwater Development Instrument
Note: The AST is also being used by universities for R&D work

"Who are your competitors? You probably will not say!"
Oh yes we will! Here is the list...
?
?
etc. all listed on the 'last page' of the Internet!
Don't take our word for it, search the WWW, use keywords like -  acoustic systems trainer, underwater,  acoustics, sonar trainer. 
However, remember to compare 'apples' with 'apples' !

"Is your trainer applicable to the military, specifically Navy and ASW work?"
The draft outline for the design was originally created by the Royal Navy, but the current system is an order of magnitude
technically superior, to it's great, great, great, grandfather!
Yes Sir! The system is currently installed in an ASW navy school, and other military establishments.......we are proud to say!

"We are looking for a 12 bit resolution sonar signal analyzer...............?"
No problem! Our latest version of the SSA (Sonar Signal Analyzer) has 12/14/16 bit resolution, and connects to a  USB 1.1 0r USB 2 port.

"How about CTFM sonar operation?"
Thanks to the Royal Norwegian Navy we can now show CTFM (Continuous Transmission Frequency Modulated) ranging sonar operation on the AST.

"Is the AST capable of performing gated rms voltage measurements?"
The Sonar Signal Analyzer has a very convenient cursor measurement feature which allows this type of measurement.
Measurements have been made on the PRF Gated CW output drive voltage.

"What is the size of the largest tank you can offer.....?"
Currently we can offer an acrylic tank measuring 3m x 1m x 1m, approx 10' x 3' x 3'.

"....Lloyds Mirror effect (surface interference) experiment?"
This effect appears naturally in the regular tank (1.2m x 600mm x600mm) when it is not acoustically damped, due to the sidelobes,
and reflections from the underwater surface, and the sides of the tank.

"....sonar source beam pattern measurement.....?"
A very simple experiment reveals the mainlobes and the sidelobes of our transducers.

"....monostatic and bistatic target strength measurement....?"
Multiple targets, and transducers are supplied with the AST to enable this investigation.

"....and is it possible to create vortices around the miniature propellers.....?
Yes, especially with the 5 bladed prop.

"Can we generate a frequency response plot of a transducer operating around 200kHz.....?
Very easily, and automatically with the built in sweep function in the Sonar Signal Analyzer.

"Is there a four channel version of the Sonar Signal Analyzer.....?
Yes, see the HS4.

"Is it possible to measure transducer Source Level and TVR in this tank.....?
Now under discussion with NPL (National Physical Laboratory).

"What about Doppler?"
Yes, see the list of lab experiments on the data sheet.

"......constructive and destructive interference demonstration?"
No problem! This is a good visual which gets the trainees thinking!