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This module describes our testing setup and the results we obtained.

Testing and results:

Our testing array consisted of four microphones borrowed from the electrical engineering lab, four audio to USB converters, and a USB hub that was then connected to the computer running the program. We tested two different setups (positions) for the array of microphones, a square and a parallelogram. Again, we simulated the rifle impulse with a hand clap. Our results are as follows:

First Array: Square

Microphones at (0, 0, 0), (0, 2, 0), (2, 0, 0), and (2, 2, 0)

Position (X,Y,Z) Results Tau (1,2,3,4)
(0,0,0) (-651.2859, -313.7830, 0) 0 0.0118 0.0103 -0.2602
(0,0,0) ( -199.8994, 272.4750, 0) 0 0.0064 -0.0028 0.4928
(0.5,-7,0) (1.0e+003*-1.1840, 1.0e+003*0.0451, 0) 0 0.0030 -0.0117 0.4828
(0.5,-7,0) (1.0e+003*3.8188, 1.0e+003*1.3335, 0) 0 0.0218 0.0303 0.4928
(8,1,0) ( 1.0e+004*1.1917, 1.0e+004*0.0959, 0) 0 0.0018 0.1032 0.4828
(8,1,0) (1.0e+003*7.0765, 1.0e+003*0.0780, 0) 0 0.0118 -0.0726 -0.4460
(1.5,19,0) (1.0e+004*-1.0404, 1.0e+004*-0.1080, 0) 0 0.0118 0.1132 -0.4460
(1.5,19,0) ( 1.0e+003*2.4049, 1.0e+003* 0.7235, 0) 0 0.0118 0.0203 0.4828
(-3,2,0) (1.0e+003*3.7463, 1.0e+003* 1.3085, 0) 0 0.0218 0.0303 0.4828
(-3,2,0) ( 1.0e+004*-1.8326, 1.0e+004*0.1534, 0) 0 0.0118 0.2061 -0.4460
(-4,-2,0) ( 1.0e+003*-1.0406, 1.0e+003*-0.1446, 0) 0 0.0018 0.0103 -0.4560
(-4,-2,0) ( 1.0e+003*3.5954, 1.0e+003*0.8343, 0) 0 0.0118 0.0303 0.4928

Second Array: Parallelogram

Microphones at (0, 0, 0), (-0.5, 7, 0), (3, -1, 0), (3.5, 4, 0)

Position (X,Y,Z) Results Tau (1,2,3,4)
(0,0,0) (-201.4001, 63.0702, 0) 0 -0.0911 0.0096 0.0068
(0,0,0) ( 2.7784, -7.2170, 0) 0 -0.0070 0.0081 -0.0038
(0.5,-7,0) (1.0e+003* 0.7510, 1.0e+003*-3.3145, 0) 0 -0.0711 0.0203 0.4828
(0.5,-7,0) (1.0e+004*1.5821, 1.0e+004*-0.2474, 0) 0 0.0218 0.1232 0.4828
(8,1,0) (-50.6356, -11.9636, 0) 0 0.0018 -0.0726 -0.0745
(8,1,0) (858.3622, 88.1823, 0) 0 0.0118 -0.0726 -0.0745
(1.5,19,0) (-40.0023, -925.3581, 0) 0 -0.0711 0.0303 0.1213
(1.5,19,0) ( 1.0e+003*2.6500, 1.0e+003*1.2213, 0) 0 0.0218 0.0203 0.4928
(-3,2,0) (1.0e+003*2.4049, 1.0e+003*0.7235, 0) 0 0.0118 0.0203 0.4828
(-3,2,0) (1.0e+004*-1.2287, 1.0e+004*0.1966, 0) 0 0.0218 0.1232 0.3071
(-4,-2,0) (1.0e+003*-5.6438, 1.0e+003*-0.0804, 0) 0 0.0118 -0.0726 -0.3531
(-4,-2,0) (1.0e+003*1.7925, 1.0e+003*0.2009, 0) 0 0.0018 0.0203 0.3899

As can be seen above in both of our test setups the scale (originally measured in feet) was off by a large magnitude. The second setup, the parallelogram did resulted in less of an error in scale, but there was still a large discrepancy. Although the scale was off, the ratio of X and Y (shown by the position of the clap) was correct even if the magnitude was off.

Besides discrepancies in scale we did have issues with our results for tau, which represented the time delay of the audio reaching the various microphones. We were unable to synchronize the microphones and get them all to begin recording simultaneously. We did try calibrating them but the recording delays of the microphones changed each time so our calibration was an average, and therefore not exact. This meant that the microphones had a delay (of about a tenth of a second) between the first one beginning to record to the last one. In some cases, the microphone that should have recorded the sound first began recording before the other microphones, making it appear that that microphone heard the sound last. These issues overall led to skewed results for the various values of tau in our testing. Because the results depended so much on the time delay, none of our results gave the correct location of the origin of the sound. We did however manage to get the general direction of the sound correct about 50% of the time.

The results that we produced were far from what we expected or desired. Although we did manage to get the general direction in about half the cases we were nowhere near determining the exact position. The problem was most likely caused by the inability to the properly calibrate or synchronize the recording of the microphones. There are a variety of ways that could have solved this problem such as an external trigger that started the microphones at the same time or running the microphones on four different programs that fed into one other program that then analyzed the data. Microphone sensitivity could also possibly improve the results.

Overall, our results do determine the general direction of the sound and prove that multilateration can be used to help pinpoint location.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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