Difference between revisions of "Projects:2021s1-13010 Socially Distant Radar"

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== Background ==
 
== Background ==
 
=== What is passive radar? ===
 
=== What is passive radar? ===
The most significant difference between passive and active radar is that passive radar utilises existing transmitters to illuminate targets. In this project we are using a digital audio broadcast (DAB) signal as our transmitter. The radiation scattered from the target is captured at recievers placed remotely from the transmitter.
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Passive radar can be described as a set of radar techniques that utilise existing signals as their transmitting source. This is the significant distinction between passive and active radar, as the latter uses a dedicated transmitter and single antenna for both transmitting and receiving. Another further distinction is that the transmit sources used in passive radar systems are noncooperative sources as opposed to active radar where the form of the signal is optimised for the radar function.  
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[[File:Multistatic Passive Radar System.png|thumb|right|Multistatic Passive Radar System]]
 
[[File:Multistatic Passive Radar System.png|thumb|right|Multistatic Passive Radar System]]
  
 
=== Advantages of passive radar ===
 
=== Advantages of passive radar ===
 
*The receiver emits no signal of its own, so the passive radar’s signal and location are undetectable by its targets and hence completely covert.
 
*The receiver emits no signal of its own, so the passive radar’s signal and location are undetectable by its targets and hence completely covert.
*Passive radar systems make use of existing transmitters, so the cost of passive radar is much lower than conventional radar. There are no rotating elements, no transmitter and low power requirements.
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There are many advantages of using passive radar, many of these are of significant interest to the defence industry, particularly for air defence systems because it provides situational awareness. The main benefits of passive radar are listed below:
*Passive radar has many applications in the defence industry (specifically air defence systems) as it provides the surveillance data to support situational awareness.
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• Since an existing transmitter is used, the passive radar receiver and its location is undetectable.
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• Relatively low cost because a passive radar system does not require a transmitter, rotating elements and has low power requirements.
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Passive radar systems are inherently resistant to jamming due to its location being unknown.
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• Almost any emission can be used as the basis of a passive radar.
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These advantages can all be attributed to the use of an existing transmitter as the reference signal for the passive radar system. Some examples of transmitters include FM radio, DAB radio, DVB-T or digital television signals, and GSM or cellular network.
  
 
== Method ==
 
== Method ==

Revision as of 13:39, 24 October 2021


Introduction

Radars use radio waves with the principle of echolocation to estimate the location and velocity of targets. A radar system consists of a transmitter producing radio waves, a receiver to collect any scattered waves and a series of processing steps to obtain useful information about any target(s) present. In recent times, passive radars have gained prominence as they use `transmitters of opportunity’, which greatly lowers cost and detectability. A modern radar system often uses a phased array antenna, capable of generating a number of beams to improve the ability to resolve targets with different directions of arrival. For this to work, the multiple channels need to be coherent or phase locked, which present a great technical challenge. An alternative is to use a multi-static system – one with multiple pairs of transmitters and receivers – to provide angle resolution. This project uses a number of 2-channel passive radar systems to detect targets on an ellipsoid and computes the intersections of these ellipsoids to resolve the target in angle. This project will develop skills and knowledge in a key technology of interest to defence. Many of the hardware and software know-how are easily transferable to other fields such as communications and RF engineering. It offers an opportunity to work with scientists and engineers in the defence sector, exposing you to professional practice in a major growth industry in South Australia.

Project team

Project students

  • Angela Vanderklugt
  • Michael Makris

Supervisors

  • Dr. Brian Ng
  • Nathan Misaghi (DST)

Objectives

The objective of this project is to be able to detect and localise targets with a multistatic passive radar system utilising digital audio broadcasting (DAB) illumination in South Australia. With the use of a multistatic network to localise targets to latitude, longitude, and altitude.

Background

What is passive radar?

Passive radar can be described as a set of radar techniques that utilise existing signals as their transmitting source. This is the significant distinction between passive and active radar, as the latter uses a dedicated transmitter and single antenna for both transmitting and receiving. Another further distinction is that the transmit sources used in passive radar systems are noncooperative sources as opposed to active radar where the form of the signal is optimised for the radar function.

Multistatic Passive Radar System

Advantages of passive radar

  • The receiver emits no signal of its own, so the passive radar’s signal and location are undetectable by its targets and hence completely covert.

There are many advantages of using passive radar, many of these are of significant interest to the defence industry, particularly for air defence systems because it provides situational awareness. The main benefits of passive radar are listed below: • Since an existing transmitter is used, the passive radar receiver and its location is undetectable. • Relatively low cost because a passive radar system does not require a transmitter, rotating elements and has low power requirements. • Passive radar systems are inherently resistant to jamming due to its location being unknown. • Almost any emission can be used as the basis of a passive radar. These advantages can all be attributed to the use of an existing transmitter as the reference signal for the passive radar system. Some examples of transmitters include FM radio, DAB radio, DVB-T or digital television signals, and GSM or cellular network.

Method

Results

Conclusion

References

[1] Australian Communications and Media Authority (2020). What is digital radio? | ACMA. [online] Acma.gov.au. Available at: https://www.acma.gov.au/what-digital-radio#digital-radio-versus-internet-radio [Accessed 9 Apr. 2021].

[2] Eleceng.adelaide.edu.au. 2021. Guide to technical writing - Derek. [online] Available at: <https://www.eleceng.adelaide.edu.au/personal/dabbott/wiki/index.php/Guide_to_technical_writing> [Accessed 15 April 2021].

[3] Griffiths, HD & Baker, CJ 2017, An introduction to passive radar , Artech House, Boston, [Massachusetts] ;

[4] Kaira.sgo.fi. 2021. $16 dual-channel coherent digital receiver. [online] Available at: <http://kaira.sgo.fi/2013/09/16-dual-channel-coherent-digital.html> [Accessed 17 March 2021].

[5] Mark A. Richards, Mark A. Richards, James A. Scheer & William A. Holm 2010, Principles of modern radar (Vol. I: basic principles)., vol. 1, SciTech Publishing.

[6] Vierinen, J., 2021. Building Your Own SDR-based Passive Radar On A Shoestring. [online] Hackaday. Available at: <https://hackaday.com/2015/06/05/building-your-own-sdr-based-passive-radar-on-a-shoestring/> [Accessed 20 March 2021]. ‌Wiki.gnuradio.org. 2021. Tutorials - GNU Radio. [online] Available at: <https://wiki.gnuradio.org/index.php/Tutorials> [Accessed 11 March 2021].