Direction of arrival
Encyclopedia
In signal processing literature, direction of arrival denotes the direction from which usually a propagating
wave
arrives at a point, where usually a set of sensors are located. This set of sensors forms what is called a sensor array. Often there is the associated technique of beamforming
which is estimating the signal from a given direction. Various engineering problems addressed in the associated literature are:
Wave propagation
Wave propagation is any of the ways in which waves travel.With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves....
wave
Wave
In physics, a wave is a disturbance that travels through space and time, accompanied by the transfer of energy.Waves travel and the wave motion transfers energy from one point to another, often with no permanent displacement of the particles of the medium—that is, with little or no associated mass...
arrives at a point, where usually a set of sensors are located. This set of sensors forms what is called a sensor array. Often there is the associated technique of beamforming
Beamforming
Beamforming is a signal processing technique used in sensor arrays for directional signal transmission or reception. This is achieved by combining elements in the array in a way where signals at particular angles experience constructive interference and while others experience destructive...
which is estimating the signal from a given direction. Various engineering problems addressed in the associated literature are:
- Find the direction relative to the array where the underwater sound source is located.
- Direction of different sound sources around you are also located by you using a process similar to those used by the algorithms in the literature.
- Radio telescopes use these techniques to look at a certain location in the sky.
- Recently beamforming has also been used in RFRadio frequencyRadio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
applications such as wirelessWirelessWireless telecommunications is the transfer of information between two or more points that are not physically connected. Distances can be short, such as a few meters for television remote control, or as far as thousands or even millions of kilometers for deep-space radio communications...
communication. Compared with the spatial diversity techniques, beamforming is preferred in terms of complexity. On the other hand beamforming in general has much lower data rates. In multiple access channels (CDMA, FDMA, TDMATime division multiple accessTime division multiple access is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This...
), beamforming is necessary and sufficient. - Various techniques for calculating the direction of arrival, such as Angle of ArrivalAngle of arrivalAngle of arrival measurement is a method for determining the direction of propagation of a radio-frequency wave incident on an antenna array...
(AoA), Time Difference of Arrival (TDOA), Frequency Difference of Arrival (FDOAFDOAFrequency difference of arrival , also frequently called differential Doppler , is a technique analogous to TDOA for estimating the location of a radio emitter based on observations from other points....
), or other similar associated techniques.