Multi-Mode Radar White Paper
multi-mode-radar-white-paper.pdf
by Mark Radford CEO of Blighter Surveillance Systems:
Blighter Surveillance Systems is a small company in Cambridge UK which employs 29 people. It is a world leading designer and manufacturer of electronic-scanning radars and surveillance solutions. Our solid state micro Doppler radars are deployed in 35 countries to deliver round the clock all-weather protection along borders, for coastal facilities, at military bases, and to guard critical national infrastructure such as airports, oil and gas facilities and palaces. The Blighter family of radar products can be used to detect a wide variety of moving objects including: crawling and walking persons, land vehicles, boats and low flying aircraft (including Drones/UAVs). The radars use a microwave radio signal to scan areas of air, land or water which can extend up to 32 km in range and up to a full 360° in azimuth.
My Comments
While working with GMTI mode on the GA-ASI UAV Lynx radar in Ku band, I often thought that the type of processing being used in Blighter would be useful if we had an AESA. Clutter reduction is critical when detecting slow small targets. A problem at Ku band is that it can't see through foliage, so we couldn't detect targets hiding in the bushes or under trees with foliage. We used space time adaptive processing (STAP) processing to map clutter return in range-doppler space, but this requires training and assumptions about clutter statistics. The problem with an AESA is coherent bandwidth. In order to get very high resolution in range, wide bandwidth is needed. Phased arrays, unless using true time delay, tend to be narrowband. Long time dwell enhances micro-doppler resolution, so wide bandwidth is not needed to resolve and recognize slow moving targets, and separate drones from birds or men from animals. Blighter seems to be using just about every AI and signal - spatial processing trick I know of, and maybe a few I don't to get superior detection and tracking of UAV, USV, and UGV drones for a very reasonable price and SWAP.
A couple relevant areas I encountered at CACI may apply. The ASDE-3 radar was being used at airports in the US to detect runway incursions and foreign objects. False targets resulted from multipath bouncing off aircraft and buildings. For airport security we developed a multisensor fusion and control system called IMPASS to integrate multiple radars.
Summary:
The paper discusses the advancement of radar technology that has enabled the development of multi-mode radars capable of simultaneously detecting targets in air, ground, and water domains. Traditional radars were limited to single modes optimized for specific applications like air traffic control, ground surveillance, or coastal monitoring. However, emerging threats like small drones, covert boats, and crawlers require a multi-domain capability. Multi-mode radars leverage technologies like active electronically scanned arrays (AESA), solid-state transmitters, and digital waveform generation to adapt their operation based on the target environment, while offering affordability and compact size compared to large military systems.
"Why is Multi-Mode Radar Required?" from the white paper:
The growth in the commercial and hobby use of drones has created an increasing demand for precision 3D detection, especially for small hobby drones. This has generated new challenges across the air, ground, and water domains that existing single-mode radars cannot effectively address:
Ground Domain:
- Drones demand accurate 3D spatial detection within the airspace above traditional 2D perimeter areas monitored by ground radars.
- Drones can be used by criminal actors for reconnaissance and can carry payloads, travel at varying speeds, and change direction quickly, challenging radar detection.
Air Domain:
- Traditional air traffic control radars are designed to detect large manned aircraft flying at high altitudes.
- Small hobby drones typically fly lower than manned aircraft and can bypass aircraft geofencing restrictions if hacked.
- It is critical to precisely locate drones in airspace, as even small ones can damage large aircraft.
Water Domain:
- Traditional coastal radars monitor cooperative vessels like ships and boats with radar reflectors.
- Modern challenges include detecting small non-reflective boats used for illegal immigration that try to avoid detection.
- Smugglers use semi-submersibles and unmanned surface vehicles that are smaller than traditional boats.
- Drones are employed for reconnaissance of landing areas and contraband drop-offs.
- Changing environmental sea conditions create a variable radar operating environment.
No single traditional radar type can effectively detect and track all of these emerging air, ground, and water-based threats simultaneously. This is driving the need for new multi-mode radar capabilities.
Blighter A800 is a 3D
multi-mode radar
Blighter Surveillance Systems' A800 3D multi-mode radar
The A800 is a newly launched radar that can operate all three modes (air, land, and sea) simultaneously. It is designed specifically for border surveillance, base security, and military applications that require scanning the air, land, and sea domains from a single radar system.
Key capabilities of the A800 include:
- Maximum range of 10-20 km
- Can detect small Group 1 drones up to 6 km away
- Can detect micro unmanned aerial systems (UAS) up to 2 km away
- Leverages multi-mode simultaneous scanning capability of large military radar antennas but packages it into a smaller, more affordable system
- Offers density of coverage ideal for modern threats like small covert vessels that can only be detected out to 10 km by most coastal radars
- Instead of a few large long-range radars, allows use of multiple low-cost multi-mode radars providing overlapping coverage
- Effective at detecting low, slow, and small land, water, and air threats concurrently with traditional larger targets
- Specifically designed to detect small consumer "hobby" drones, a key challenge for contemporary radars
The A800 provides an affordable way to gain comprehensive multi-domain surveillance by covering large areas and scanning air, land, and sea simultaneously using its adaptive modes. This allows detection of emerging small and slow threats across domains alongside traditional larger targets like aircraft, vehicles, and boats.
The Blighter A800 is a 3D multi-mode radar, based on the latest generation monopulse antenna technology. It provides the unique ability to use its optimised air security modes to search for small drones, and at the same time, can use its ground/sea surveillance modes to search for surface targets over land and water.
The A800 performs its air, ground and sea detection functions simultaneously, allowing multi-mode operation with simple user setup. The A800 multi-mode radar uses triple, transmit and receive, radar-beam spotlighting to focus all its energy on targets of interest. The radar ignores ground clutter and off-beam targets, giving rapid scanning of a 90° wide by 40° high cone.
Mark Radford Offers Insight to UK Government C-UAS Action Group
12/05/2021 Posted In: Press Releases
Cambridge, UK, May 12, 2021 – Mark Radford, Co-Founder & CTO of Blighter Surveillance Systems (‘Blighter’, www.blighter.com), the British designer and manufacturer of electronic-scanning radars and surveillance and Counter-Unmanned Aerial Systems (C-UAS) solutions, has given a presentation to the first C-UAS Industry Action Group, a virtual roundtable with C-UAS policy and technical leaders established by the UK Home Office’s Joint Security and Resilience Centre (JSaRC).
Mark offered his insight into the role of radar in C-UAS and highlighted the need for more government support to facilitate the accessibility of anti-drone test centres as well as the importance of sharing information between C-UAS providers and government.
Speaking after the event, Mark said:
“Those of us in industry have long been pushing for more government support in the field of C-UAS, especially given the threat posed by hostile drones to our national security and infrastructure. JSaRC brought in a great mix of academia, industry and government for some open discussions on the present and future challenges facing this sector and it is encouraging to see the government step up to address them.”
Blighter Sea Clutter Filter Enhances E-scan Radar's Effectiveness For Coastal and Harbour Security
CAMBRIDGE, United Kingdom, Nov. 6, 2014 /PRNewswire/ -- Blighter Surveillance Systems (www.blighter.com), a British electronic-scanning (e-scan) radar and sensor solution provider, has enhanced its Blighter e-scan radar's effectiveness for coastal and harbour security with a raft of new features including a sea wave clutter filter.
Photo - http://photos.prnewswire.com/prnh/20141105/156936
Photo - http://photos.prnewswire.com/prnh/20141105/156937
The new features will enable its radar to protect complex coastlines from intruders such as smugglers, pirates, illegals and terrorists using jet skis, kayaks and rigid inflatable boats (RIBs) at ranges of up to 10km away. The Blighter radar is now able to detect and locate these small and slow moving targets day and night and in almost all weather conditions, in rough seas, heavy rain or dense fog.
Mark Radford, CEO of Blighter Surveillance Systems, said: "Protecting coastlines from illegal intruders is a growing concern for countries the world over. Our Blighter coastal security radar's unique algorithms and Doppler signal processing enables it to detect the small and uncooperative targets that traditional coastal surveillance radars such as vessel traffic systems and maritime radars are simply not designed for."
The Blighter low power solid-state passive electronic scanning array radar features frequency modulated continuous wave (FMCW) transmission technology combined with sensitive Doppler target detection. The sea clutter filter enables the Doppler signal-processing unit to filter out sea wave clutter returns in both velocity and amplitude.
"As colour is to CCTV images, Doppler is to radar detection. It adds a third dimension to target detection so that not only are targets identified in azimuth (compass bearing) and range but they are also discriminated by Doppler velocity, the relative speed of each target," added Mark Radford. "The sea clutter filter automatically classifies the sea clutter and removes it and uses a non-moving target detection filter to extract static targets from the Doppler filter enabling it to detect static boats, buoys and other features in a coastal or port environment."
The Blighter radar is about the size of a large brief case and uses a fraction of the power of other radars – it transmits only four Watts of power and consumes just 100 Watts allowing operation via solar panels and easy installation in difficult areas to reach such as rocky or inaccessible coastal regions. The radar's low data bandwidth requirement also allows remote operation over narrowband wireless links or satellite communication systems.
Like most radars, Blighter integrates with a range of electro-optic camera systems – and other situation awareness sensors - and these elements are controlled through the BlighterView HMI command and control (C2) software platform. BlighterView can also integrate with AIS transponders, PIDS systems, fusion and target/video tracking elements.
For more information about the Blighter coastal security radar or other products from Blighter Surveillance Systems, please visit www.blighter.com, telephone +44 (0) 1799 533200 or Email us.
A newly published white paper on Coastal & Harbour Security can be downloaded here: http://www.blighter.com/news/white-papers.html
High-resolution photography to accompany this press release can be downloaded here:
-http://www.blighter.com/images/images/pr/3d-doppler-view-of-sea-clutter-detection-with-separate-target-rgb-high-res.jpg
-http://www.blighter.com/images/images/pr/blighter-b400-series-coastal-security-radar-close-up-high-res.jpg
-http://www.blighter.com/images/images/pr/blighter-b400-series-coastal-security-radar-with-liteye-aquila-camera-system-high-res.jpg
Media contacts:
Martin Brooke
Martin Brooke Associates
Tel: +44 (0) 1223 882174
Tel: +44 (0) 7776 135402
Email
Nick Booth
Blighter Surveillance Systems
Tel: +44 (0) 1799 533200
Tel: +44 (0) 7801 398712
Email
SOURCE Blighter
Related Links
"Development of BLightER, a cost sensitive, high performance FMCW radar,"
M. Radford, "Development of BLightER, a cost sensitive, high performance FMCW radar," First European Radar Conference, 2004. EURAD., Amsterdam, Netherlands, 2004, pp. 161-164.
Abstract: This paper describes the unique design methodology used by Plextek to design BLightER, a portable and lightweight, low EOSI radar. By designing the radar using components and technologies that offer significant cost and availability advantages, a highly cmteffective radar design has been achieved.
keywords: {Costs;Radar antennas;Radar signal processing;Transmitters;Microwave antennas;Switches;Design methodology;Electronic equipment;Qualifications;Portable computers},
URL: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1396509&isnumber=30354
SECTION I. Introduction
The defence equipment market is characterised by its plethora of expensive, custom-designed systems. Electronic equipment is generally designed to satisfy a specific goal, this being specified by end-users, defence organisations or systems providers.
In designing a system that tries to achieve all elements of the performance envelope, unusual architectures and new specialist technologies are often required. Each specific requirement can add to the cost of the equipment either through increased component cost or increased processing or qualification effort.
There is much comment on the use of “off-the-shelf technology, whether it be Commercial (COTS) or Military (MOTS) grade. Off-the-shelf technology is supposed to offer lower costs and faster development timescales due to much of the design work having already been completed. The classic problem with the COTS based procurement model is that requirements are often still not changed to fit the available technology and therefore the equipment still requires customisation. The - cost of customising an existing piece of equipment can often be close to that of developing the equipment from new.
Instead of designing equipment up to a desired specification, Plextek's radar design team took a very different approach. The team were asked the question, “What readily available, low-cost technology can be used and what level of performance will that achieve?” If this is applied to all aspects of the radar design then some interesting product characteristics are achieved.
The most important characteristic is that using low-cost design techniques and components allows a product to be developed that costs a fraction of existing systems. Although the radar does not offer the same level of performance as conventionally designed military radar, additional units may be used to provide the coverage expected of the previous systems. The lower price tag also offers the opportunity to use the radar in applications that would traditionally have been prohibitive by cost, such as perimeter security or installation monitoring.
SECTION II. Architecture of Radar Hardware
The integrated radar consists of a number of standard system blocks including: Antennas, Transmitter, Receiver, Signal Processing, Data Processing and Display. Novel features of each sub-system are described below.
A. Antenna Selection
When reviewing the selection of antennas used on existing portable radar, it became apparent that standard design approaches are generally used. In most cases a conventional dish antenna is used in conjunction with mechanical steering. Such an antenna obviously offers near optimum characteristics - low loss, low sidelobes, but it can be bulky and requires a mechanical steering structure.
Over the past decades, much work has been performed on antenna structures that offer a frequency sensitive squint. Their implementation however, especially at microwave frequencies, has been hampered by the lack of suitable materials. It is now possible to model and design simple antenna structures on microwave substrates to create antennas that offer adequate performance for many applications. Significantly though, they are simple, cheap and very robust as well as obviating the need for mechanical rotation.
The appropriate radar band was selected on the basis of bandwidth availability, required scan angle and compactness of antenna for a given beam width. The Ku band is a good place to start and can offer a beamwidth for an antenna approximately 40cm long.
B. Transmitter Component Selection
The transmitter for an FMCW radar requires a spectrally pure CW source at much lower powers than a traditional pulsed Radar. The choice of the . band also happens to well match satellite VSAT communication systems, resulting in a relative abundance of useful microwave components.
As an example, rather than buying a pre-packaged transmitter module at a cost of some to , a single 2 Watt Power Amplifier can be purchased for approximately . Admittedly, this needs packaging, but it offers a lower cost, high performance solution that can be more closely integrated with other components.
C. Receiver Design
The receiver system, including the homodyne mixer, requires great care in its design. Huge dynamic ranges are encountered with an FMCW system, and unfortunately, saturation from any return signal will be catastrophic for all other radar returns hidden beneath the saturating signal. The LNAs, Mixers and filters must all be able to cope with a dynamic range well in excess of . Fortunately, commercial satellite band components offer adequate performance at very reasonable cost.
D. Frequency Synthesis Solutions
The radar contains a number of features that make it covert. Firstly, its transmitter power is only around , not dissimilar to standard mobile telephones. More importantly, the mode of operation using an FMCW chirp modulation combined with a broad-spectrum frequency band usage makes the radar difficult to detect.
Fast hopping, broad band synthesizers are not new, however the availability of digital waveform generation using FPGAs and commercial chip sets now allows greater freedom in the selection and programming of transmitter frequencies and waveforms. (FPGAs — Field Programmable Gate Arrays can be considered as user programmable hardware offering high performance and advanced digital hardware design but with software programmability)
In common with the signal processing section below, the aim is to design a system initially offering abundant resources then select and fine tune a lower cost technology for production units. Plextek used a high performance FPGA based frequency synthesizer to develop an optimum frequency regime. Given precise design requirements a commercial device can be selected to offer a better value, smaller, but possibly compromised solution.
E. Signal Processing Platform
The radar is designed to provide detection of moving targets. By reducing the radar target information output to an absolute minimum, the communications infrastructure for either a single or multiple radar deployment can be significantly rationalised. To achieve this, significant signal processing is required to cleanly detect valid targets yet suppress clutter and other false alarms.
To minimise development timescales and costs, an in-house designed DSP card is used to provide an abundance of signal processing resource. Front-end processing, characterised by fast and repetitive number-crunching uses an FPGA (Field Programmable Gate Array) while the more adaptive and flexible processing functions are contained in a high performance micro-processor (The Motorola MPC7410).
For production units, this high performance and power hungry platform will be replaced with lower cost commercial components. Modern mobile telephones with their audio processing and gaming engines provide enormous amounts of processing power at low cost and using very little power. Furthermore, communications technology currently being designed into automotive electronics to satisfy the rapidly expanding telematics industry provides the same technology in more robust packaging, suited to the harsh environments expected of the radar.
Microprocessors containing the ARM9 core offer clock speeds equivalent to mid-range PCs, yet come integrated with a wealth of interfaces necessary to support the radar design.
F. Standard interfaces
The radar includes a number of additional facilities that make the radar easier to install and use. Rather than designing custom interfaces, the emphasis has again been placed on using modules wherever possible. Such modules de-risk the development programme and offer considerable savings in parts and design cost.
For a portable radar, the ability to use it immediately after deployment can be a major benefit. To support this both GPS and Digital Compass modules are fitted. Once placed on the ground, the radar knows where it is and which way it is pointing.
A GPS module is cheap enough to be fitted as standard even if it is not required for fixed installations.
Digital compasses are available in a range of technologies all offering different price/performance trade-offs. The printed antenna technology used in the radar offers limited angular accuracy and therefore a lower performance compass matched to the accuracy of the antenna offers a more affordable solution.
One of the radar's capabilities is the ability to communicate with other sensors and the user display using wireless and wired networks. It is tempting to design a custom wireless interface for such a security product that offers longer operating range and possibly more data security. However, the availability of Personal Computer products, with all the drivers and applications developed and generally debugged, at minimal prices offers a perfectly adequate solution for most applications.
For the basic radar wireless networking, the use of a range of the IEEE802.11 wireless standards offers a high performance, secure interface encapsulating thousands of man-hours worth of hardware and software development in a $20 solution. Standard Operating Systems then allow networking protocols and facilities to be layered on top of the wireless link to provide endless networking capabilities using TCP/IP.
G. User Interface
For the user interface, the almost universally available Microsoft Internet Explorer was chosen. The radar itself contains a web server that serves up a radar specific Java Applet to a PC or PDA. The Java Applet runs within Internet Explorer and provides a user display and interface. Radar data and information from other embedded sensors, including GPS and Compass, is transferred from the radar to the Java Applet for the operator to view. Connection between the radar and the PC or PDA is either by Ethernet or IEEE802.11 wireless connection. This means that almost any PC or PDA with a network connection and Internet Explorer can operate the radar without any additional software even over the Internet and at absolute minimum cost.
SECTION III. Performance
By taking the approach of using technology that is common and readily available rather than developing custom solutions, Plextek has had to face certain compromises in the design of the radar mainly affecting performance.
The portable radar market is by no means large, but it is characterised by a small number of well matured products that over the years have had many millions of Euros pumped into their development. Some of their specialised features include:
High transmit power for long range detection of potentially 10's of km.
Multiple radar modes optimised for particular applications. Eg long range sensitivity vs minimum range capability.
Complex user interfaces that provide every conceivable configuration option.
Robust construction suited to every climate.
Considering the standard technology being used for this radar, there is little chance of being able to match the characteristics of these radars. The major compromise is radar detection performance.
The combination of more lossy antenna, low transmit power, commercial frequency synthesis losses and limited signal processing budget mean that this radar may only be able to detect a man at about I compared to ranges as high as for some systems.
Despite the performance loss, there are some benefits in a small number of crucial areas:
Cost - Using standard components, materials, processes and technology allows the BOM (Bill of Materials) cost to be driven down dramatically.
Weight - Using mobile phone type technology allows significant weight savings as the components, their enclosure and battery can all be much smaller
Compactness - the simple antenna technology combined with the compact electronics allows the unit, display and battery to be carried comfortably by one man.
SECTION IV. Conclusion
Plextek's unique approach, applying standard and easily obtainable components and technologies, has allowed it to develop an extremely cost effective portable radar system that offers performance falling only slightly short of other considerably more expensive systems. Modem microwave materials and techniques allow low cost antennas to be fabricated. Selection of a frequency band near to that used for satellite communication provides a wealth of low cost yet high performance components. Use of signal processing technology that provides abundant resources minimises development time and allows radar algorithms to be optimised with ease.
Combined with a user interface based around a web browser, the radar offers rapid, adaptable development with easily available and low-cost components and wireless access via a PDA.
ACKNOWLEDGEMENT
The author wishes to acknowledge the assistance and support of all those who have and continue to contribute to the development of the radar and this paper.
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