<< Chapter < Page Chapter >> Page >
A description of what direction of arrival is and a discussion of our specific algorithm for determining it

Direction of arrival estimation

Given the basic foundation in beamforming the other modules in this section have established, we would like to extend the usefulness of the technique into new domains. One application of interest outside of simply creating a directional antenna is to identify the direction from which a known source is broadcasting, called Direction of Arrival Estimation.

Basic premise:

In all cases, direction of arrival estimation relies upon an a priori estimate of the signal’s arrival direction. If no estimate can be made, the array’s response is swept around the unit circle, and a decision rule is applied to its output. Locations where this decision rule is satisfied are assumed to correspond to locations of the known source. If an estimate exists, more sophisticated adaptive processing techniques may be applied to determine the source’s location with greater precision.

Specific implementation:

To simplify the process of direction estimation, we make a few assumptions about the configuration of our sensor network and its environment. The first assumption we make is that our source is sufficiently distant from our sensor network for the received wavefront to be considered linear. This first assumption is called the Far Field Approximation, and simplifies the computation of steering and weighting vectors. The second assumption we make pertains to the noise environment the sensor operates within. We assume that noise (if present) is ideal Gaussian noise, simplifying the structure of our signal detection segment.

These assumptions having been made, the detection algorithm is quite simple. We step through angles over which the array can look, feeding an input from a known location. The output of the array is then fed through a matched filter, which has the effect of computing the cross-correlation between the signal received by the array and the known signal of the transmitter. The peak value of that correlation is then stored with its corresponding angle. Upon completing the sweep over angles, the angle with the highest peak correlation is taken to be the most likely location of the signal source. This algorithm is described below in pseudocode:


Function AngleEstimation{ Angle<- 0 Angles<- [] //empty set of anglesMagnitudes<- [] //empty set of peak amplitudesWhile Angle<2*pi { Output<- Beamformer(Angle, input) Output<- Matched_Filter(Output) Angles<- concatenate(Angles, Angle) Magnitudes<- concat(Magnitudes, max(Output)) Angle<- Angle + pi/32 //increment to next angle }SourceAngle<- Angles[index(max(Magnitudes))] Return SourceAngle;}

Questions & Answers

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
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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?
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
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
preparation of nanomaterial
Victor Reply
Yes, Nanotechnology has a very fast field of applications and their is always something new to do with it...
Himanshu Reply
good afternoon madam
what is system testing
what is the application of nanotechnology?
In this morden time nanotechnology used in many field . 1-Electronics-manufacturad IC ,RAM,MRAM,solar panel etc 2-Helth and Medical-Nanomedicine,Drug Dilivery for cancer treatment etc 3- Atomobile -MEMS, Coating on car etc. and may other field for details you can check at Google
anybody can imagine what will be happen after 100 years from now in nano tech world
after 100 year this will be not nanotechnology maybe this technology name will be change . maybe aftet 100 year . we work on electron lable practically about its properties and behaviour by the different instruments
name doesn't matter , whatever it will be change... I'm taking about effect on circumstances of the microscopic world
how hard could it be to apply nanotechnology against viral infections such HIV or Ebola?
silver nanoparticles could handle the job?
not now but maybe in future only AgNP maybe any other nanomaterials
I'm interested in Nanotube
this technology will not going on for the long time , so I'm thinking about femtotechnology 10^-15
can nanotechnology change the direction of the face of the world
Prasenjit Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Berger describes sociologists as concerned with
Mueller Reply
Got questions? Join the online conversation and get instant answers!
QuizOver.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Direction of arrival estimation. OpenStax CNX. Dec 18, 2012 Download for free at http://cnx.org/content/col11470/1.2
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Direction of arrival estimation' conversation and receive update notifications?