A Persistent Ground Based Surveillance Challenge

The idea of persistent ground based surveillance is not a new one, and anyone that has ever been to a town or city in the UK will understand full well what it means.

In an era where personnel numbers are challenged, threats are everywhere and cycle time between observation and action, especially for high-value targets, becoming increasingly compressed, an all-seeing eye can provide many advantages in a variety of operational scenarios.

The idea of persistent ground-based surveillance is not a new one, and anyone that has ever been to a town or city in the UK will understand full well what it means. But in a defence and security context what caught my eye and prompted the idea for this post was a news story from Belfast Live about something being sold on eBay!

The item in question was from the Troubles era, a hedgerow cam.


Secret British Army camera used to spy on IRA on sale on eBay

A covert British Army camera used to spy on the IRA and other terrorists have appeared for sale on eBay. The seller is asking £60 for the so-called hedge-cam that was used in Northern Ireland during the Troubles. Four people have been watching the activity on the camera today which is being sold as equipment once used by the Army’s notorious Special Forces Special Reconnaissance Regiment in Northern Ireland.

The cylindrical item which houses a camera, is disguised in dark green and grey camouflage and a security source told Belfast Live: “These covert cameras could be put almost anywhere and everywhere particularly from the late 1970s to end of Operation Banner. “Normally they would be buried at the side of the road, in a hedge, in a tree, even in the gardens of some of the men of evil. They were important pieces of equipment because if people were recorded being at their place of work or at home when a terrorist incident took place, they could be immediately eliminated from interest.

“If they had 100 players and they could eliminate 98 of them from enquiries then the focus would then be on the two not accounted for. “The provo commanders would always blame non-existent informers especially when electronic intelligence gathering caught them.

The device itself was made by Kylmar, now General Dynamics.

The last paragraph caught my eye particularly, we know that sowing seeds of suspicion is an enduring and valuable tactic in counter-insurgency operations, organisation expend valuable energy trying to find non-existent traitors and curtail operational activity. Now of course, this is 2016, not the seventies. Enemies have a much greater awareness of electronic surveillance, but that does not mean the tactic has no value any more.

We might also consider how they might be used on a conventional battlefield. Could they be used at potential chokepoints, placed nearby tunnels, road intersections or likely river crossing points? Non-covert surveillance has value, yes, but covert surveillance also has value, even in conventional scenarios.

Current Systems

Am pretty certain, if we could produce a hedgerow cam in the seventies, would can produce something much better today and a casual search reveals many suppliers and types of system, from the ubiquitous ‘nanny cam’ and ‘rock cam’ to ruggedised low profile Inmarsat BGAN terminals linked to advanced thermal imaging cameras.

Deployable Surveillance

There are all available now, and nothing unique. Seraphim in Israel is a typical supplier of high-end persistent ground surveillance equipment.

[tabs] [tab title=”Can you see it”] Seraphim UGS 1
[/tab] [tab title=”Seraphim UGS”] Seraphim UGS 3
[/tab] [tab title=”Video 1″]
[/tab] [tab title=”Video 2″]
[/tab] [tab title=”Video 3″]
[/tab] [tab title=”Video 4″]
[/tab] [/tabs]

It is interesting that Seraphim market some of their systems as ‘unattended gap fillers’ because that is exactly what they do, personnel and other systems cannot be everywhere all the time.

Long endurance power cells are also available, the example below is from SFC Defense

SFC Energy power Cell

Cobham also has a range of systems for covert surveillance.

But despite their availability, these kinds of systems have not found widespread use in all but the most specialised and limited scenarios. The simple reason is one of bandwidth availability and high cost, plus the ever vexing question of how to turn huge volumes of data into useful intelligence in a timely manner.


So the challenge, if there is one, is to drive down the cost to such a level that they can become widespread and almost, disposable.

This also strikes me as the kind of challenge that would react well to an open competition, run by DSTL or one of our many esteemed universities, like a DARPA Grand Challenge.

For any sensor system, there are fundamental building blocks, sensor, control, power and communications. Once they have been perfected, the packaging and form factor needs to be decided. For an unattended system, they are all challenging, for a persistent sensor system, power is probably the single biggest problem. If we are to make them as ubiquitous as small arms they have to be cheap, to make them cheap they either have to be made in vast quantities or exploit off the shelf technology.

That means a unit price of less than £500


The most obvious type of sensor is an optical one i.e. a camera. Fixed focus or zoom, daylight or infra-red, given the huge development activity with mobile telephones, the capabilities of modern small lens camera modules are simply out of this world compared the hedgerow cam at the top of this page.


Full HD CMOS camera modules are readily available in retail quantities are available for less than £5, VGA sensors, even less.

VGA Camera Module

In the smartphone business, there are a number of key suppliers; Sony, Omnivision, Toshiba, SK Hynix, Samsung, LG and HTC. These manufacturers can supply camera and lens modules that incorporate image stabilisation, optical zoom, autofocus and infra-red colour correction. Wider aperture systems are also becoming more readily available for significant improvements in low lighting performance.

Toshiba produced the record-breaking 41-megapixel sensor for the Nokia 808 and also market a number of 8 and 21-megapixel sensors for the Project Ara modular smartphone. As the burgeoning Indian and Chinese smartphone market increases demand and volume, companies like OmniVision are selling 16-megapixel sensors that can capture 30fps HD video for less than a few US Dollars.

Infra-red illuminators would allow usage in nighttime conditions but an emitter is not a great idea in a passive surveillance system for both detectability and power reasons so the best solution would be to utilise low light models and rely on ambient illumination sources, or simply accept a compromise. The mobile phone market is also driving innovation here, using twin lens modules and in module noise reduction for example. Depth of field is reduced but for some applications, this may be acceptable. What is certain though is that small optical sensors, from the smartphone market, are increasingly capable and power-efficient.

A typical overcast day is between 1,000 lux and 20,000 lux intensity, a full moon is less than 1 lux and a quarter moon at 0.01 lux. Low light cameras are generally classified as requiring illumination between 0.1 Lux and 0.01 Lux. Moonlight level cameras between 0.1 lux and 0.002 lux, ultra-low light cameras can operate at less than 0.001 lux. As an example, JVT produce a 2-megapixel module that is 38mm square and can operate in colour at 0.001 lux. It can encode and compress the 1920×1080 image using an onboard H.264/H.265 system. Accept a higher lux threshold and the resolution can be improved, 2560×1920 for example, at 0.05 lux, in colour.

Spend a bit more, get a bit more, but the mass market devices at less than $50 are extremely capable. Although a day or low light optical sensor might seem like the obvious choice, seismic or even audio sensors could also be considered.


In addition, a signals intelligence payload might also replace the optical sensor.

Software-defined radio has its own open-source software and hardware community and they do often quite incredible things with low-cost TV tuner cards, single board computers and software. SDR simply moves signal processing into the software.

SDR defined by Wikipedia

Software-defined radio (SDR) is a radio communication system where components that have been typically implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which used to be only theoretically possible.

VHF radios work in the 30-300 MHz frequency range. Cellular telephones, depending on a number of factors, operate between 850 MHz and 1,900 MHz. WiFi operates between 2.4 GHz and 5.9 GHz, whilst Bluetooth operates at 2.4 GHz. GPS operates at 1.57 MHz and 1.22 MHz. This presents many challenges as different hardware will be required but the aforementioned $20 TV Tuner card can be used to listen across a 50 to 1,750 MHz frequency range which puts many communication systems in range. Spend $300 and the open-source design HackRF One transceiver is available, this has an incredible 10Mhz to 6Ghz operating frequency. Sample rates are also extremely high.

HAck RF One

There are even App Stores for SDR.

Another signals intelligence capability might be derived from proximity advertising and the fast-growing ‘smart home’ market. Proximity advertising is a technique that presents targeted advertising initiated by the presence of a device. When the device approaches it is detected and either a large screen display started or some media ‘sent’ to the device, multimedia files for example.

In ‘Smart Home’ applications, the key to much functionality is detecting when a specific person enters a specific room or building in order to initiate other things, lighting or door opening for example. Each Bluetooth device has a unique MAC address which is used for proxy identification i.e. if this MAC address is detected this person is detected. The technology used for both these applications is Bluetooth, the well-known short-range personal network system. Detection for range for 2.5 GHz Bluetooth signals can be as high as 250 metres, although operating ranges are much smaller, 25 metres is more realistic.

Although 25 metres may seem like a small detection range it might be enough when used at specific choke points. There are over two billion Bluetooth devices in circulation. Put a detector close to the entrance of an Army barracks and in peacetime, collect all the Bluetooth MAC addresses and build a database. As we have seen from the various social media posts of Russian soldiers in Ukraine maintaining operational security over soldier’s use of Smart Phones is actually quite difficult.

Now position the detector at a critical bridge and one could easily get a warning of concentrations of MAC addresses (and therefore units) in space and time for real-time intelligence of troop movements. Bluetooth is not just for Smart Phones either, keyboards, headphones and even fitness trackers are transmitters. Similar can also be achieved with GSM/3/4/5G telephones, hoovering up identification data for future location and correlation.

Cross Cueing

Cross curing one sensor to or from another has enormous potential.

With a signals payload able to show a concentration of a specific number of MAC addresses from soldiers Smart Phones at a key bridge, positive verification could be obtained by cross cueing an optical sensor at the same location. The signals payload provides a clue or marker and then the optical sensor provides both confirmation and positive evidence. Vehicle identification and quantities could confirm automatic number plate or shape recognition.

In real-time, early indications of massing or movement across specific locations could allow counter targeting. If a network of receivers was available, they could also be used for triangulation of more simple communication devices like VHF ‘walkie talkies’

Control and Processing

After collection of visual or electronic information, something has to be done with it.

The data could be transmitted raw but that would likely come at a cost of unsustainable bandwidth and power issues and so some filtering or processing would need to be conducted on-board the device. Smart Phones and operating systems like Android would make a quick and relatively easy base on which to generate such processing but as am sure most of us know, they are hardly frugal when it comes to power consumption and for an unattended sensor, this is a bad thing TM

A more realistic alternative, and one which pushes the cost right down, is the many single-board computers now available.

The British designed and built Raspberry Pi is an obvious choice but even this might be over-specified, the ridiculously cheap Raspberry Pi Zero might be just as suitable. At a whopping £4 (you read that correctly) the Pi Zero has a 1GHz processor, 512Mb RAM and comes on a package 65mm by 30mm. There are a huge variety of readymade applications and peripherals for the Pi family including cameras, as shown below on the Pi Zero

Pi Zero

Whether it is signals analysis, number plate recognition, scene change detection or storage and compression of images ready for transmission, it is in the software load that the real power of such a device will be realised. The software should also enable the tidal wave of data to be tamed, this is where the sensor cross cueing and target recognition would be advantageous.

Researchers at Georgia Tech’s School of Electrical and Computer Engineering have approached this task by limiting frame rates and combining this with an intelligent control system that recognises images through a novel pixel tracking algorithm

“What this camera is actually looking at is not pixel values, but pixels added together in all different ways and a dramatically smaller number of measurements than if you had it in a standard mode”. The always-on camera was primarily designed as a way to wake up devices. But its ability to recognize specific gestures expands the possibilities – such as a camera that wakes up with a specific pattern or movement almost like a secret handshake. “We wanted to devise a camera that was capturing images all of the time, and then once you have a particular gesture – like you write a Z in the air – it’s going to wake up,” said Arijit Raychowdhury, an associate professor in the School of Electrical and Computer Engineering. “To make that work without affecting the battery life, we wanted it to be so low power that you can power it with harvested ambient energy, such as with a photovoltaic cell.”

As we know, with imagination the art of possible is vast.


As with sensors, the idea is to use readily and commercially available components.


Although collection for later retrieval might be of value in some circumstances there is a fundamental requirement to transmit collected sensor information to users.

Communications could be continuous, on a store and forward basis, on a time-lapse or in response to some stimulus. The stimulus could be a command signal or other sensor input, movement, seismic or acoustic for example. Instead of transmitting raw data from whatever sensor is used, the actual data transmitted should be processed, compressed and transmitted sparingly.

For video, compression technology means even full motion high definition video can be transmitted at relatively low bandwidths. The latest HEVC/H.265 standard is aimed at 4k video Raw 4K video needs more than 60Mbs but with H.265, this can be reduced to approximately 20Mbs. Proprietary technology like Beamr also claims to reduce this even further, down to 10Mbs. 1080p video compressed using the older H.264 compression technology consumes roughly 6Mbs.

This is still very high for wireless transmission and higher efficiency codecs usually require higher power computing, and in turn, this generates high power consumption and greater heat. If we go much lower, VGA (640×480 pixels), but still use H.265 the bandwidth requirement drops to approximately 0.5Mbs, or double that with H.264. We would also have to question the need for full-motion colour video, reducing the colour depth and frame rate provides a massive reduction in bandwidth requirement. Dropping to 1 frame per second at 352×240 would need 6Kbs, 10 frames per second at 640×480, 180Kbs.

As can be seen, transmitting at high definition and high frame rates is probably not practicable for this kind of device but accepting frame rate, colour depth and resolution compromises certainly makes it much more feasible.

A balance would need to be found.

Means of communication…


Although satellite would be excluded on cost grounds, it could be seen as an option. The Low Profile BGAN terminal from Inmarsat is specifically designed for covert communications, it is state of the art with a state of the art price tag, about $20,000 each.

Low Profile BGAN

Offering bandwidths of up to approximately 0.5mbs it could comfortably handle video streaming, has a wake on SMS function, can be laid flat and even covered in a thin layer of soil or sand.


The most obvious means of communication for this type of device is to use cellular networks. Many studies have shown that cellular networks have remained remarkably resilient in conflict situations short of major wars with extremely high levels of infrastructure damage.

It might simply be an acceptable compromise to tolerate the risk of the device being disrupted in return for low cost and relatively low power operation. ‘Machine 2 Machine’, or M2M, terminals are sold in high volumes as everything from vending machines to street signs are increasingly connected. Yes, they would be much less secure than satellite, but there is also an advantage in hiding in plain sight. LTE modules can now be purchased for less than $50

Once connected the data would be transmitted over the cellular network and onto the internet for viewing, collection and analysis.

WiFi Internet

In built-up areas there are likely to be a large number of WiFi routers and hotspots that can be accessed automatically, using automated password cracking where required. A high gain WiFi antenna does not need to be large and can access WiFi signals from a broad area, hopping from to another to avoid detection and improve diversity.

High Altitude Platform (HAP)

One area that does show enormous potential for low power internet connectivity is the high altitude platform concept. Although this is not new, it is looking increasingly likely with Facebook and Google both investing large sums in the technology needed to realise it. Google Project Loon and Facebook unmanned teams are both collaborating and competing at the same time, but whatever the final outcome, the technology is progressing at pace.

With the Airlander 10 soon to make its debut in the UK and the Airbus Zephyr under contract from the MoD, there are likely to be a number of options for generating high altitude internet connectivity.


WiMAX like bandwidth (approx. 10Mbs) to multiple devices over a 400km2 plus area seems to be the current aim point which would provide more than enough coverage for multiple devices.

Low Power Radio Networks with Backhaul

One concept that could also be promising in situations where sensor placement would be relatively dense is to generate an ad-hoc mesh network between the devices and then use a single communications hub for backhaul transmission.

Multiple devices connected over low cost and low power radio networks to a single satellite communication uplink would enable the high cost of the satellite equipment to be shared across multiple devices. As the ‘Internet of Things’ and smart metering progresses, the industry is producing a number of Low Power Wide Area Network (LPWAN) technologies. Although they tend to operate at lower bandwidths they may still be enough and are attractive because of their operating ranges, most over 10km for example, and low power/cost.


Power consumption is very important, the Pi Zero (at idle and with HDMI disabled) sips power at a rate of 0.7 Watts per hour (120 mA). If more power is needed for sensor processing (as I think it would) then one of the more powerful single-board computers would be needed. A Pi 2 Model B is much more powerful than the Zero but still only consumes 1.2 Watts per hour (240 mA) at 5 Volts.

This calculation does not take into account any communication transmission, this is likely to be much greater (although the Pi figures above do include WiFi). The real-time continuous transmission will of course require much more power than transmit on sensor cue, command or on a timed basis. Each application would need to balance communication frequency with power available.


A 100,000 mA ‘telephone power bank’ readily available on a certain global auction site for £15 could power a Raspberry Pi for about 10-12 days. (calculator here) Connect multiple such cheap power banks and a reasonable battery life could be generated. After use, the device could be retrieved, the battery changed covertly, or, simply abandoned. Modern power tool batteries are also increasingly efficient and offer significant capacity. 5 to 10 days may be suitable for some scenarios but for persistent surveillance, more would be needed.


Widely available, solar chargers could provide an enduring power system for sensors but they are not always discrete.

Careful placement of the collection panels would be needed but given the potentially small amount f power needed, this could be easier than imagines, especially in urban settings. Collection panels can also be separated from the sensor and associated electronics, they do not need to be in one large box. Mass market solar phone chargers that output enough power to charge a battery bank suitable for the example processor above can be obtained for £20-30 and are no larger than a couple of smartphones.

Power Cell

Where sunlight cannot be guaranteed and extended durations are needed, a fuel cell might be an effective means of generating sufficient power. The types shown above are very high power and very high cost but yet again, turning to the mass market reveals some interesting devices, mostly aimed at recharging cell phones. Off-grid power systems for CCTV, industrial process control and lighting are also becoming more widespread, although they are still relatively expensive and bulky.

Mains and Parasitic Power

In urban or even semi-urban environments, it Is probably just as easy to plug it into a mains socket

Problem solved!

This might not be as ridiculous as it seems, again, in many situations, mains power remains operable and one more device plugged into a house or industrial buildings power cabling might be just as stealthy as if it were hidden and operating on battery power.

Form Factors

The hedgerow cam at the top of this page was fitted into a metal cylinder but that does not mean all similar devices have to be the same. Put the sensor, processor, power and communications system into a black Peli case and it looks exactly what it is. Split the four modules or put them into common objects that do not look like Peli cases and they become much easier to conceal. In an urban environment, it should be relatively easy to conceal the sensor given it is likely to be no larger than a box of matches.

The principle is to hide in plain sight so attaching boxes to street furniture, bridge supports, cell towers and signage is unlikely to arouse any suspicion as they are already adorned in similar. Think creatively and match those boxes to the intended environment; rubbish containers, rubble, agricultural equipment, abandoned cars, shop signs, drainage pipes, street lights and advertising signs.


If we want to spend a lot, and after all, defence is expensive, there are suppliers that can deliver exactly what is needed. Creating a wireless and covert CCTV network across the strategic locations in a city like Basra is perfectly feasible with off the shelf technology.


It is expensive.

So, the point of this article is to ask if by a combination of accepting compromises and utilising off the civilian shelf components we can lower the price of deployment to such a point that makes such a network of sensors feasible and useful.

Stabilisation, security operations, or even some parts of conventional conflicts could be enhanced by pervasive and persistent surveillance using both optical and signals sensors. Throw in cross cueing and intelligent deployment and usage, and the case becomes compelling, I think.

It would also be interesting to throw the challenge of creating the building blocks open to those outside of the defence industry. Instead of going to market with a set of performance thresholds first, set the price point and a few vague objectives and then see what the academic and hobbyist community comes up with.

For £100k we could provide a kit of parts to one hundred participants. For those participants, offer another £50k in prize money and some bragging rights. Am a big fan of competition and experimentation, let’s see what we can get without the traditional defence primes coming anywhere near it!

Change Status

Change Date Change Record
 01/03/2017 initial issue
11/09/2020 Minor updates and spelling errors corrected
Notify of
Newest Most Voted
Inline Feedbacks
View all comments
August 10, 2016 5:50 am

Despite all the information collection tools, bandwidth and capacity is still a major bottleneck in UGS (unmanned ground sensor) processing. If a single node is transmitting “live” video 24/7, you end up with one sensor “hogging” one monitor and you’re still using one man to monitor the feed from one sensor. Most of the time, the “sensors”, NV and TI, are on some sort of “trigger” so that unless something is there to be detected, the sensor remains passive. This lets a single control “node” monitor multiple sensor clusters.

Not to mention the best “processor” is still a human being to decide if the camera caught something worthwhile, or simply crap (which happens rather often since one of the “triggers” usually is a motion detector, so lots of pictures of moving leaves).

When we detect/capture something, the person monitoring would take a look at the image captured, then crop and compress the image to a much lower resolution if worthwhile as most cameras have a much higher resolution than can be transmitted out practically from a signal set, then bump the image out to HQ, but more often than not, we just count the images and send the total out by text unless we see something we can’t recognise.

This means that ironically, the biggest size limitation isn’t how small you can make the equipment, but how small can the screen go without making it unusable for humans since you have to “see” the image, sometimes enlarged for clarity, crop it and compress it, especially at night or objects that are captured at a distance.

No point having a postage stamp sized computer when the user can’t make out what the screen is showing! :)

Normally, we have 3 sensor “clusters” monitored by a single Toshiba Toughbook.

Total weight of the system? 48kg. Excluding your normal load. @#$%^&*(

Stephen Duckworth
Stephen Duckworth
August 11, 2016 5:11 pm

I like the idea of a competion spread through UK Universities Computing/Electronic engineering departments with the IPR going to the winning(winners) University.
Software could be written ( probably already exists) that can filter the data so that only relevant information is transmitted limiting power consumption and the OPFOR’s ability to find the device by its emissions. Multiple devices at any chosen location could be set up with only one actually active with a backup dormant waiting to activated by remote if the first is discovered.
Anything that is cheap that makes the OPFOR spend hard earned Ruble’s/Yuan on countering it “is a good thing™” IMHO.

August 12, 2016 12:22 pm

@TD I would have thought there’s a lot more to add on software aspects ? Facial recognition would be one, but I expect there must be others as well.

August 14, 2016 6:52 am

I agree with Obsever below. The “man in the loop” is the best decision maker on what is valid and what is not.It helps that technplogy can help to limit this workload with regards to monitoring video feed.
My home web cam software has an alert facility. My web cam “knows” what the outside area of my house looks like. If it sees a change in that picture it can do a number of things such as send me an email alert of a possible intruder or take a picture and record video and store it in the cloud. Where I am though trees and leaves are not so much of an issue!
The technology is already there and should be exploited. But you will still need a “man in the loop” to asses it.

August 14, 2016 7:45 pm

being an estonian, i´ve been thinking about something similar on context of more conventional warfare than COIN etc.
basicly a CCTV (throwaway) camera, for uses like good old WW2 spotter on church tower. or in hedge :) or hanging on a tree along highway.
basicly only good enough sensors to differentiate between civilian cars and BMP/BMD/BTR´s for mine ambushes/arty strike etc.
it should be passive, even video signal should go through optical cable, meaning it would be also jam-proof. and cheaper too. if one could retrieve it, it´s good, if not, oh well…

this should somewhat mitigate other observ. tools deficiencies – current drones are extremely vulnerable or expensive, radars are beacons, real people are not expendable and too easily discovered (thermal imagers)

this is of course amateur´s thought´s, probably there are many flaws (visual range for example), but i was thinking among lines of WW1 trench periscope for platoon level use.

sorry for any typos and incoherent thought process

August 15, 2016 7:56 am

The main problem with this is how easy it is to track a RF signal, no matter what tech it uses.

If you put a hidden camera watching a high profile target, as stated the data needs to be fed back quickly, which means regular RF transmissions and as with surveillance tech being cheap off the shelf, so are RF scanners / trackers.

For irregular photos or short videos, that can be sent back by burst compressed signals, at random intervals, this can work, but if you need near real-time information, the camera is going to be discovered quickly.

The problem is that whilst the likes of ISIS are fairly low tech, their leadership is less so, ok not modern military level of tech but they don’t need that to track RF signals, and these are the guys that we would be trying to spy on.

August 15, 2016 8:43 am

The range of the sensor cluster transmission is very limited, only about 200-300m +/-, very low power, so the RF leakage problem is minimal. The biggest advantage the UGS gives us is the fact that you can monitor multiple axis of movement simultaneously, which is a big help for units that are short of manpower. The alternative is to put a 2 man OP for each axis = 6 men excluding relief, which is too much for a recon team.

One of the other criteria for a UGS is the total lack of traceable or classified technology. This way, you can lose a sensor and still not get tracked back or lose anything sensitive, though if the enemy is tech savvy, expect an infantry sweep of the area soon. That is why fibre optics are not used (besides the problem involved with 3 rolls of 300m cable and the damn knots that can happen with “land lines”), they can be followed back to the central processing node.

I do agree with some computer assisted processing, but you really should not rely on it too much. I’ve seen a computer classify a pickup truck as an A-vehicle. And knowing the processing sequence of the computer, it does have a logical flow process for that classification, but it’s still a bit dumb compared to a human. How the UGS classes vehicles (the low tech way) is via a “seismic spike” that measures ground vibrations, so a B-vehicle technically should not produce too much “crunching” noises that indicate an armoured vehicle. In that case I mentioned however, the vehicle was on a gravel path, so lots of “crunch” and vibrations which got it miss-classified. There are very high tech ways that involve microwave imaging and image comparison, but that is very, very high end tech and not common (or at least I have never encountered it in person yet, note the caveat).

A human being will get it in one look. A computer can be led down the garden path if the information it received was out of programmed values.

August 15, 2016 10:28 am


If they can limit the RF leak and and reduce the chance of discovery, then having a load laid down broadcasting back to a more expensive Sat box and then feeding back to an array of screens back in the UK, could be very effective.

We have seen with broadcast TV/sport that one person can monitor dozens of screens looking for something ‘interesting’ happening.

However, RF is not very directional and i really don’t see how you could set these up without them being tracked, unless you are going to add to the price with a high zoom lens, which of any quality are generally pretty pricey.

August 15, 2016 12:16 pm

I won’t actually advise it since I mentioned bandwidth is limited, which is why we convert from image to text before sending back to HQ. Bandwidth and transmit time is the biggest problem, if you wanted to send video through our signals set, only God knows how long that is going to take.

Your sensor does not emit that much. Your signals/radio set on the other hand does. A CSM of mine (that same BUDS grad I mentioned in the dustup with SO) taught us that if for some reason or other you’re lost or misplaced your map and need a helo pick up, call for triangulation then hold the PTT (Press to Talk) down, count from one to ten and back. By the time you hit zero, they should have your location, so while the sensors might be able to transmit to the monitoring set with low chance of detection, it isn’t so from the monitoring set to HQ. Satellite though might work since it’s a dish pointing up.

As for directional, it actually depends on your antenna! The log periodic antenna I’m familiar with has 2 modes, if it’s vertical, it’s on omnidirectional but if it’s orientated horizontally, it becomes directional. So it depends on how you orientate and set up your antenna.

August 15, 2016 12:39 pm

In a non-warzone situation surely the best place to hide your surveillance equipment is in the bandwidth of other “transmitters”, so in mobile or radio frequencies in a city/ town environment. Hide in the background noise.

If that’s the case, then as I can buy cameras, transmitters and batteries for sub £10 – I have 2 wireless cameras that use a 9v battery and transmit to a receiver and they cost me under £10 each. Why not apply that logic to a warzone. £10,000 buys me 3,000 transmitting cameras. Place a couple of high tech “puker” ones where I want them and scatter 1,000 others around the area and let the enemy sort through that lot. If a few of them “accidentally self destruct” on finding them, even better : )

August 15, 2016 5:03 pm

In a non-warzone situation, I’m going to have to ask who is going to look for your transmitter. Unless you’re working for the other side? :)

I do agree on the cheap part though it’s also never the cameras and short range transmitters that are the limiting factor. How big/many a video screen do you need to display all the results is one of the factors, which is why when you see photos of UAV “war rooms”, you see monitors all over the place. And if I have to carry a TV monitor on my back in addition to my load, I’m going to cry. You don’t want to see a grown man cry do you? lol.

Our mother processing node is a Toughbook, off the shelf. Think they got it at bulk discount, I saw pictures of them using the same thing in a SPYDER SAM launch vehicle and HIMARS! Batteries? Other than the computer battery packs, I personally have to lug 144 AA sized Eveready batteries (36 packs of 4) out. And I’m not the only one. I swear, if we were to ever run out of batteries, the whole army would grind to a halt.

August 16, 2016 7:33 pm

In a non-war zone situation, why do we need the military involved.

I guess if your talking counter insurgency within a city (which is still sort of a war zone), whether its anti-IRA style where the city itself is at peace or Iraq/Afgan where things are a bit more of a mess, i guess you would have plenty of RF interference to lose signals in, after all even in Iraq/Afgan people have mobile phones and radio/tv’s etc.

As such would want to broadcast on public frequencies, such as using mobile phone frequencies to make sure it gets lost in the noise, which in turn brings down the cost since you could use an inexepensive mobile phone as a modem.

August 19, 2016 7:05 am

Unattended ground sensors were first used in Vietnam starting in the late 1960s, typically capturing and reporting sounds. My favourite was one placed in a VC bunker system which revealed one VC trying to persuade another not to marry his intended because her mother was a real dragon. Of course there were other modes besides sound. Whether or not they were notably useful is an interesting discussion, but they could be quite useful for providing warning of enemy approaching an ambush..

August 24, 2016 3:26 pm

Well if no-one else is going to post it I will:
Airlander 10: HAP HAP and awayyyy! Oops.


August 24, 2016 10:33 pm

Not strictly speaking a ground-based surveillance system, but if they insist on landing it like that it may well become so!

August 26, 2016 10:05 am

Possibly it should have been in the “conflict prevention from above” thread? With some better bumpers, nothing would say “stop it” more than landing a 100 metre airship on someone.

Tom Oliva
February 13, 2017 12:21 pm

One way to reduce the detectability, increase the range and reduce the power budget of wireless devices is efficient directional antennas = just saying….

Cross cue-ing sensors is a godsend … as anybody with motion detecting CCTV looking at a wide scene will attest.

Would love your thoughts, please comment.x