Human detection refers to a range of systems that identify if a human is in an area. As technology advances more and more human detection is used by governments and organizations for different purposes. On the more innocent side of the spectrum, human detection can be used to measure foot traffic through an area, or to turn on and off lights automatically; more sinisterly, human detection has been used to make databases of individuals and their habits for prosecution, China is infamous for this and its the primary reason the Taiwan riots used umbrellas and lasers to blind cameras.
Human detection really isn't new, in fact, a well trained dog was our primary human detection system for a long time. Technology has advanced, and now we have to deal with all manner of electronic sensors. For your convenience, here they are in a table:
| Passive / Active | Functional at night? | Outdoor / Indoor | Employment |
Passive Infrared | Passive | Yes | Both | Civilian, and Government |
Video | Passive* | Yes* | Both | Civilian, and Government |
WiFi/Bluetooth | Passive | Yes | Indoor* | Industrial, and Government* |
Ultrasonic | Active* | Yes | Both | Industrial, and Government* |
Radar / Microwave | Active* | Yes | Both | Civilian, and Government |
Acoustic | Passive | Yes | Indoor | Industrial, and Government* |
Chemical | Passive | Yes | Indoor | Industrial, and Government* |
Pressure-Plates | Passive | Yes | Indoor* | Industrial, and Government* |
Vibration | Passive | Yes | Both | Industrial, and Government* |
This isn't truly a complete list, however, for our purposes it will be more than sufficient. Let's start by trimming the fat. We won't talk about acoustic, chemical, vibration, or Pressure sensors, if you want a general description go to the relevant citation [1].
Let’s move on to what matters.
Passive Infrared (PIR)
PIRs detect changing and moving temperatures in an area. Civilian units do this by dividing the area into grids via their lens. As a person moves into view of one of the grids the sensor detects a change in heat. This change is called a ‘Pulse’, PIRs are calibrated such that they require multiple pulses before they are activated [2] and initiate an alarm, light, or camera.
(Image showing an approximation of a PIRs detection array)
Government and High end PIRs do not use lenses to divide an image, instead they have a multitude of sensors that each service their own area. Effectively they function the same, however, they are much more sensitive. Quality PIRs will have an additional sensor area directly below the unit to eliminate that area as a blind spot. PIRs are better at detecting motion across its detection pattern rather than towards the unit; this is due to the lense/grid layout, on most units there are more horizontal grids than vertical grids.
So, PIRs are activated by sudden changes of heat, therefore, all we must do is disguise our thermal signature [3]. While we are waiting for thermal uniforms to become available to civilians we must settle for alternatives.
Mylar sheets are usually the first method that comes to mind, against PIRs they perform substandard. Mylar reflects its environment and the environment’s heat, when outdoors it reflects the sky. During the day, mylar is too hot, and at night, mylar is too cold. However, Indoors and under medium-heavy tree canopy, mylar can perform quite well. Mylar tarps with the matte side facing towards the PIR perform better outdoors with a similar indoor performance.
Thick wool blankets are the next most common thermal cloak, they perform adequately for thermal optics but not for PIRs. Wool takes time to adjust to the environmental temperature [4], so moving between environments (outdoors-indoors) will cause temperature differences and trigger most PIRs.
UV umbrellas are, in our experience, the best option for PIRs. Umbrellas with a matte exterior and reflective interior will absorb less of your body heat, as it is reflected back to you. The thin canopy material of umbrellas will quickly change to match the air temperature at night and the ambient object temperature (air temp + sun reflection) during the day.
To most effectively use an umbrella against a PIR: Make yourself as small as possible (minimizing the size of your heat signature), hold the umbrella towards the PIR with a completely extended arm (Minimizing the body heat transfer to the umbrella), and position the umbrella so that 20% is above the PIR and 80% is below it (Minimizing exposed body parts).
(Image showing a PIR and proper exploit technique)
Video
Surveillance cameras with the capacity for human detection have existed for some time and have become high enough resolution to not only determine the identity of a person, but with a network of cameras, can also map that person's movements. Luckily security cameras are faced with the same problem as our eyes, they only work in favourable conditions. Facemasks, nightfall, and route planning are key to countering video cameras.
(Image of a street security camera paired with human detection AI)
You may not be able to stop a camera from seeing you, but you can definitely stop a camera from identifying you [5]. Facial recognition uses some combination of the following:
Distance between the eyes,
distance between the forehead and the chin,
depth of the eye sockets,
shape of the lips,
shape of the ear, and
shape of the chin.
If you cover these key parts of your face you will be disguised from automated systems of identification, however, we must go a bit deeper. More advanced surveillance systems do not need to identify your face, if they can't see your face they will tag you and identify you by your clothes, skin color, or (when paired with other sensors) your phone's IMEI address identifier. The computer will store this list of traits and where it saw them. Should it be needed, a human moderator can then look for these traits to see where you came from, went to, and people or vehicles you interacted with.
The best solution to surveillance cameras is nightfall and route planning. For enough money, you can make a security camera that does not need an IR illuminator in most conditions. With even more money, you can make a security camera that operates with 'IR+' technology [6]. Civilian surveillance systems without supplementary IR will fail long before a Gen 3 tube, however, we can't rely on darkness to keep us safe from high end government security cameras [7]. Always avoid visible and IR lights, walking through open terrain, and keep alert for passive security cameras.
(Image of IR floodlights used at government substation - captured with Sionyx Aurora Pro, the Sionyx colour image processing turns IR lights into the blue hue seen)
WiFi and Bluetooth
WiFi and Bluetooth detection refers to two concepts, the first is that of detecting signals that Personal Electronic Devices emit, the second refers to detecting interference caused in WiFi signals by humans.
Let’s start by stating the obvious, respect OPSEC, leave the phone at home. As you move around your phone searches for WiFi routers, if it detects one, it sends a signal out which contains your SSID data, and IMEI address. Your IMEI address is unique to your phone and can be stored as proof that you were in an area. Many systems are set up to detect the outgoing signal of phones and other electronic devices. This means no phones, smart watches, wireless headphones, and trackers (Apple Airtags and other BTLE devices). Your GPS is safe as that doesn't emit any signal.
Next, WiFi interference detection. This is an emergent technology that speculation tells us is already employed by the US Government. There is not any real way to counter it either, at least at the moment.
(Image - Left half showing the participants actual position, right half showing where the WiFi interference detection predicted they were)
Ultrasonic, Radar, and Microwave (URM)
URM sensors function as sonar, sending out pulses and listening for their response. Advanced URM sensors know how far away an object is, the direction to the object, and the object's speed. Additionally, radar and microwave are able to detect motion through walls, high end radar sensors can see through almost all materials but metal. Microwave and radar can and are vehicle-portable with some rare cases of man-portable units.
(Image depicting examples of ultrasonic and radar human detectors)
As URM sensors are active (sending out a pulse) they can be detected, though, this requires specialist equipment. Radar detection operates between 40-100GHz, most ‘police radar detectors’ operate in this range and will alert if there is a human radar detector nearby. To detect ultrasonic and microwave sensors you’ll need to find a sensor that can detect 30-500KHz (ultrasonic) or 0.3-40GHz (microwave), these are seldom sold so goodluck.
Countering URMs is not something that can be done in the field, in order to fool URM sensors you must absorb their ultrasonic/microwave/radar waves. Militaries fool radar with special paints us lowly civilians don't have access to. The next best thing we can use is deadening foam/sheeting, acoustic foam for ultrasonic sensors, and broadband foam/sheeting for radar and microwave.
Dual Technology
Dual technology refers to the combination of multiple sensor types into a detector. Most commonly is the combination of PIRs and Microwave sensors. Civilian dual tech systems are used to decrease false positives i.e. the dual tech sensor needs both the microwave and PIR to agree that there is a human in order to activate an alarm or light. Government dual tech sensors are used in order to increase the information that is gathered i.e. a security camera and WiFi detection system will take an image of you and take the IMEI address from your phone as additional proof that you are in the image.
…
Privacy is a human right. We need to move away from the mentality that hiding from big brother is a crime. It is not. It is instead a form of survival in a country or state that has become, or will become, oppressive. Stay hidden, stay safe.
[1]
Acoustic, pressure, chemical and vibration sensors are only really used in the hearts of facilities i.e. low traffic areas within or leading to protected rooms or vaults.
Acoustic sensors are microphones that are linked to an AI. Most commonly they are set up to detect human footsteps, or in some very high security instances, human breaths.
Pressure plates are exactly what they sound like, effectively impossible to detect.
The only chemical sensors we have ever worked with have detected Carbon Dioxide. These are slow functioning, as it takes time for carbon dioxide to reach abnormal levels when someone enters a moderately sized room.
Vibration sensors can be set up to only trigger for human footprints, however, the only times we have ever worked with them they have been set up to detect any vibration what-so-ever. Government vibration sensors are capable of detecting the heartbeat of someone sitting down on the floor.
[2]
This is an effectively accurate oversimplification of how pulses work. A radiator or the sun rising and heating up an area will not trigger the PIR as they heat up evenly and slowly. Additionally, each grid is divided into two, a positive and negative sensor, these sensors receive your body heat at slightly different times allowing each grid to send multiple pulses. Effectively, walking only 6 feet horizontally across the PIRs grid pattern will likely send 4 or more pulses.
Most civilian PIRs are calibrated such that slow moving objects will not trigger a pulse. This leaves some PIRs open to exploit, as a rule of thumb, movement that wouldn't startle an animal won't trigger these PIRs. The problem is that it is impossible to be certain which units are configured this way.
[3]
As thermal fusion optics and surveillance systems become much more prevalent we will release a dedicated essay into ‘Counter Thermal’. TBD.
[4]
Let's say that you are approaching a building during the day, you drape the wool blanket over yourself and walk past the PIR and into the building. Your blanket, which has been outdoors and exposed to the sun, is 85°F. The blanket worked outdoors as everything has been exposed to the sun and so the average outside object’s temperature is also 85°F, however, now that you have moved indoors, another PIR inside the building has detected you. This is because the average indoor object temperature is only 75°F. It takes time for wool blankets to adjust to a new environment's temperature, further to this, the blanket can’t adjust while you are wearing it as it will instead adjust to your temperature.
[5]
There is an exploit to disguise yourself that isn’t talked about here. Wearing Disruptive clothing can cause the AI to not understand you as a person, effectively a form of ‘digital camouflage’. The reason we don't discuss this is because it's hard to employ correctly, makes the wearer stand out to any human observer, and may likely be obsolete as AIs advance.
[6]
IR+ is our own made up term that we will use to refer to IR lasers, lights, and cameras that operate between 900-8000 nm with supplementary technology to aid in image quality. IR+ is light beyond what can be seen by Gen 3 night vision and typically involves wavelength patterns that can't be detected by thermal devices. Suffice to say, with enough money you CAN see in zero light conditions.
[7]
The ‘advanced’ security cameras I'm referring to are not really that rare, however, we can predict where they are. Traffic and inner city security cameras don't need supplementary IR, there is enough ambient light or street lighting to facilitate a good view; even in poor lunar and weather conditions. Cameras inside of buildings will use supplementary IR/IR+ as these conditions are too dark for any current tech night vision to work. High value targets will either use passive cameras capable of good image quality even in extreme low light, or cameras with supplementary IR/IR+.
The point is: be aware, that for enough money, governments can and do employ surveillance cameras that are almost as capable as your Gen 3 tubes. Source: you’re just going to have to trust us.
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