Close Menu
TechCentralTechCentral

    Subscribe to the newsletter

    Get the best South African technology news and analysis delivered to your e-mail inbox every morning.

    Facebook X (Twitter) YouTube LinkedIn
    WhatsApp Facebook X (Twitter) LinkedIn YouTube
    TechCentralTechCentral
    • News

      Vodacom fibre play pushes Maziv valuation above Telkom’s

      20 July 2025

      Crypto industry shoots for mainstream adoption

      20 July 2025

      Vodacom’s Maziv deal gets makeover ahead of crucial hearing

      18 July 2025

      Cut electricity prices for data centres: Andile Ngcaba

      18 July 2025

      Takealot taps Mr D to deliver toys, pet food and future growth

      18 July 2025
    • World

      Grok 4 arrives with bold claims and fresh controversy

      10 July 2025

      Samsung’s bet on folding phones faces major test

      10 July 2025

      Bitcoin pushes higher into record territory

      10 July 2025

      OpenAI to launch web browser in direct challenge to Google Chrome

      10 July 2025

      Cupertino vs Brussels: Apple challenges Big Tech crackdown

      7 July 2025
    • In-depth

      The 1940s visionary who imagined the Information Age

      14 July 2025

      MultiChoice is working on a wholesale overhaul of DStv

      10 July 2025

      Siemens is battling Big Tech for AI supremacy in factories

      24 June 2025

      The algorithm will sing now: why musicians should be worried about AI

      20 June 2025

      Meta bets $72-billion on AI – and investors love it

      17 June 2025
    • TCS

      TCS+ | Samsung unveils significant new safety feature for Galaxy A-series phones

      16 July 2025

      TCS+ | MVNX on the opportunities in South Africa’s booming MVNO market

      11 July 2025

      TCS | Connecting Saffas – Renier Lombard on The Lekker Network

      7 July 2025

      TechCentral Nexus S0E4: Takealot’s big Post Office jobs plan

      4 July 2025

      TCS | Tech, townships and tenacity: Spar’s plan to win with Spar2U

      3 July 2025
    • Opinion

      A smarter approach to digital transformation in ICT distribution

      15 July 2025

      In defence of equity alternatives for BEE

      30 June 2025

      E-commerce in ICT distribution: enabler or disruptor?

      30 June 2025

      South Africa pioneered drone laws a decade ago – now it must catch up

      17 June 2025

      AI and the future of ICT distribution

      16 June 2025
    • Company Hubs
      • Africa Data Centres
      • AfriGIS
      • Altron Digital Business
      • Altron Document Solutions
      • Altron Group
      • Arctic Wolf
      • AvertITD
      • Braintree
      • CallMiner
      • CambriLearn
      • CYBER1 Solutions
      • Digicloud Africa
      • Digimune
      • Domains.co.za
      • ESET
      • Euphoria Telecom
      • Incredible Business
      • iONLINE
      • Iris Network Systems
      • LSD Open
      • NEC XON
      • Network Platforms
      • Next DLP
      • Ovations
      • Paracon
      • Paratus
      • Q-KON
      • SevenC
      • SkyWire
      • Solid8 Technologies
      • Telit Cinterion
      • Tenable
      • Vertiv
      • Videri Digital
      • Wipro
      • Workday
    • Sections
      • AI and machine learning
      • Banking
      • Broadcasting and Media
      • Cloud services
      • Contact centres and CX
      • Cryptocurrencies
      • Education and skills
      • Electronics and hardware
      • Energy and sustainability
      • Enterprise software
      • Fintech
      • Information security
      • Internet and connectivity
      • Internet of Things
      • Investment
      • IT services
      • Lifestyle
      • Motoring
      • Public sector
      • Retail and e-commerce
      • Science
      • SMEs and start-ups
      • Social media
      • Talent and leadership
      • Telecoms
    • Events
    • Advertise
    TechCentralTechCentral
    Home » Science » The amazing camera that can see around corners

    The amazing camera that can see around corners

    By The Conversation9 December 2015
    Twitter LinkedIn Facebook WhatsApp Email Telegram Copy Link
    News Alerts
    WhatsApp

    camera-corner-640

    How can a person see around a blind corner? One answer is to develop X-ray vision. A more mundane approach is to use a mirror. But if neither are an option, a group of scientists led by Genevieve Gariepy has developed a state-of-the-art detector which, with some clever data processing techniques, can turn walls and floors into a “virtual mirror”, giving the power to locate and track moving objects out of direct line of sight.

    The shiny surface of a mirror works by reflecting scattered light from an object at a well-defined angle towards your eye. Because light scattered from different points on the object is reflected at the same angle, your eye sees a clear image of the object. In contrast, a non-reflective surface scatters light randomly in all directions, and creates no clear image.

    However, as the researchers at Heriot-Watt University and the University of Edinburgh recognised, there is a way to tease out information on the object even from apparently random scattered light. Their method, published in Nature Photonics, relies on laser range-finding technology, which measures the distance to an object based on the time it takes a pulse of light to travel to the object, scatter, and travel back to a detector.

    Laser light fired at the floor is scattered in a spherical wave. It reflects from the hidden object and makes its way back to the SPAD detector, where the noisy data is processed to reveal the hidden object. Gariepy et al./Nature Photonics
    Laser light fired at the floor is scattered in a spherical wave. It reflects from the hidden object and makes its way back to the SPAD detector, where the noisy data is processed to reveal the hidden object. Gariepy et al./Nature Photonics

    In principle, the measurement is quite simple. A laser pulse is bounced off the floor and scatters in all directions. A small fraction of the laser light strikes the object, and the back-scattered light is recorded on a patch of floor — the “virtual mirror” — next to the spot the laser strikes. Because the speed of light is known and constant, by measuring the time interval between the start of the laser pulse and the scattered light reaching the patch of floor, the position of the object can be triangulated.

    However, the devil is in the detail. The timing measurement needs to be accurate to within about 50 thousand billionths of a second (5×10-11, or 50 picoseconds), and the light levels that must be detected are extremely low. Overcoming both of these obstacles requires some serious laser and detector technology. The laser pulses used for the timing measurement are just 10 femtoseconds (10 million-billionths of a second, or 10-15) long, and each pixel in the ultra-sensitive “camera” (known as a single-pixel avalanche diode array, or SPAD) used to image the patch of floor is essentially an ultrafast stopwatch that records the arrival time of the scattered light pulse to within a few hundred-billionths of a second.

    The complications do not end there. Light scattered from the object of interest reaches the virtual mirror of the floor, but so does light scattered from every other object in the vicinity. The success of this technique requires that the two be separated, the “signal” of the hidden object from the background noise of everything else.

    This is achieved by using the fact that the hidden object the device is trying to detect is moving, while other nearby objects are not. Because the moving object generates a signal in the virtual mirror that changes with time, it can be filtered from the constant background signal produced by the stationary objects of the surroundings.

    A histogram is created of photon arrival times for every pixel, which must then be processed to remove background objects from the target object. Gariepy et al/Nature Photonics
    A histogram is created of photon arrival times for every pixel, which must then be processed to remove background objects from the target object. Gariepy et al/Nature Photonics

    The final complication is that the timing measurement for scattered light arriving at a single point on the virtual mirror and recorded by a single pixel in the detector unfortunately doesn’t locate the object to a single unique position. A similar time delay could result from objects located at any number of different positions located an appropriate distance from the virtual mirror.

    While the timing data from a single pixel only locates the object to a range of positions, the range is different for each pixel. However, it turns out that there is only a single position at which the timing condition is satisfied simultaneously for all pixels, and this allows the object to be unambiguously identified from the background signals.

    The prototype camera system allows the object’s position behind the wall to be localised to within a centimetre or two, and by making measurements every few seconds the camera can also detect the speed of a moving object. In contrast to previous methods, which required long data processing times, the new method can track moving objects in real time. At present, it’s limited to locating objects up to 60cm away from the virtual mirror on the floor, but this should improve to around 10m, as well as to more closely detect the shapes of hidden objects as well as their positions.

    So while it’s not quite as promising, or as convenient, as the science-fiction powers of X-ray vision, the study’s authors note that the technology has interesting future applications in areas such as surveillance — to detect a moving person behind a wall, for example — or in car safety systems to detect incoming vehicles approaching around corners.The Conversation

    • Claire Vallance is professor of physical chemistry at the University of Oxford
    • This article was originally published on The Conversation


    Claire Vallance Genevieve Gariepy
    Subscribe to TechCentral Subscribe to TechCentral
    Share. Facebook Twitter LinkedIn WhatsApp Telegram Email Copy Link
    Previous ArticleVodacom walks away from Neotel spectrum
    Next Article Free-to-air broadcasters to feel the squeeze
    Company News

    Vertiv to acquire custom rack solutions manufacturer

    18 July 2025

    SA businesses embrace gen AI – but strategy and skills are lagging

    17 July 2025

    Ransomware in South Africa: the human factor behind the growing crisis

    16 July 2025
    Opinion

    A smarter approach to digital transformation in ICT distribution

    15 July 2025

    In defence of equity alternatives for BEE

    30 June 2025

    E-commerce in ICT distribution: enabler or disruptor?

    30 June 2025

    Subscribe to Updates

    Get the best South African technology news and analysis delivered to your e-mail inbox every morning.

    © 2009 - 2025 NewsCentral Media

    Type above and press Enter to search. Press Esc to cancel.