New research shines a light on how expert mapmakers at Ordnance Survey see the world differently

Apr 19, 2024

3 min


OS Remote Sensing Services survey team updating OS MasterMap using the latest aerial imagery (Image credit: OS)


  • Aston University psychologists worked with Ordnance Survey to assess how surveyors use 3D aerial images when making maps
  • Humans naturally assume light comes from above, but experienced surveyors can interpret visual cues to assess topography regardless of the light direction
  • It is the first time it has been shown that experience can radically alter natural human assumptions about lighting and could improve surveyor training.


Researchers at Aston University have found differences between experienced Ordnance Survey (OS) mapmakers and novices in the way that they interpret aerial images for mapmaking, which could lead to improved training processes for new recruits.


OS is well known for its travel and walking maps, but is also responsible for maintaining Great Britain’s national geographic database. Every time a building is demolished or developed, or a new road and path built, the map must be updated.


Aerial photographs are taken of the area that has changed, either from a plane or using drones, and expert mapmakers, known as remote sensing surveyors, will examine the images to identify change and accurately redraw the map of the area.


Image pairs are presented stereoscopically, one to each eye, allowing the remote sensing surveyors to see in 3D and correctly assess the topography, such as ditches, hills and hedges.


Led by Professor Andrew Schofield, a team from Aston University’s College of Health and Life Sciences, together with Dr Isabel Sargent, previously at OS, carried out a study to understand how remote sensing surveyors interpret the shadows and highlights in images.


The researchers asked six trained remote sensing surveyors and six novices to assess 10,000 stereoscopic aerial images of hedges and ditches, which had been heavily masked with image distortions.


The stereoscopic images the aerial surveyors use for mapmaking are usually taken on sunny days. The human brain is naturally wired to interpret light as coming from above. However, the light does not come from above in the OS aerial images, it depends on the position of the sun. In the UK, north of the equator, light comes slightly from the south, thus appearing to come from below in images viewed by the surveyors.


The researchers wanted to see how manipulating the direction of the light would affect the surveyors.


Professor Schofield and the team swapped the image pairs between the eyes in half of the trials, so that hedges might look like ditches, and ditches look like hedges. The images were also flipped vertically on half the trials, changing the direction of the light source.


Expert surveyors were found to rely on the stereoscopic cues – the difference in images seen by the two eyes – when performing the task.


Novices were more likely to rely on lighting cues – highlights and shadows – to judge the shape and relief of an object, and assumed, as is natural, that the lighting came from above.


With the manipulated images, this meant that novices frequently made mistakes. Experts were more accurate, even when the images had been turned upside down, and some had learnt to assume that the light source came from the south, or below.


This is the first time anyone has shown that the natural assumption that light comes from above, which is common amongst many animal species, can be changed through long term experience. The researchers say that it could be used to develop new visual training techniques for remote sensing surveyors. For example, intensive exposure to repeated, difficult images can improve performance via a process called perceptual learning.


Professor Schofield said:


“This is a very exciting result. Others have shown that the light-from-above assumption can be altered by a few degrees, but no one has ever found complete reversals following long term experience.


Dr Sargent said:


“This result will help Ordnance Survey to understand the expertise of their staff and improve surveyor training and procedures.”


Remote sensing surveyor Andy Ormerod, who worked on the study, said:


“This research proves that experienced remote sensing surveyors can see the world differently. Whereas non-surveyors are used to seeing the world from one perspective, our brains have learned to view the world as seen from aerial imagery.”


Journal of Vision DOI:10.1167/jov.24.4.11

Powered by

You might also like...

Check out some other posts from Aston University

Major trial shows increasing bone density fails to cut fracture risk in brittle bone disease featured image

3 min

Major trial shows increasing bone density fails to cut fracture risk in brittle bone disease

An international clinical trial involving Aston University researchers has challenged long held assumptions about how brittle bone disease is treated in adults, after finding that substantially increasing bone density did not reduce the risk of fractures. The study, published in the Journal of the American Medical Association (JAMA), examined whether a two stage treatment using the bone building drug teriparatide followed by the bone preserving drug zoledronic acid could reduce fractures in adults with osteogenesis imperfecta, often referred to as brittle bone disease, a rare genetic condition that causes bones to break easily throughout life. Researchers followed 349 adults treated at 27 specialist centres across the UK and Europe. While the treatment led to clear increases in bone density in the spine and hip, fracture rates were no lower than among patients receiving standard care, suggesting that bone quality may matter more than bone density alone in preventing fractures in people with the condition. The findings underline a key distinction between brittle bone disease and more common bone conditions such as osteoporosis, where increasing bone density is known to reduce fracture risk. In osteogenesis imperfecta, the study suggests that bones can become denser without becoming less likely to break, indicating that the underlying quality and structure of bone tissue may play a greater role in fracture risk than density alone. Dr Zaki Hassan Smith, an endocrinologist at Aston Medical School who contributed to the research, said: “This study shows that in osteogenesis imperfecta, simply increasing bone density doesn’t necessarily translate into fewer fractures. That’s important, because it tells us that the disease is more complex than what we see on a scan. The findings help shift the focus towards understanding bone quality and how bones behave in real life, which is essential if we are to develop more effective treatments that genuinely reduce harm for patients.” Osteogenesis imperfecta is a genetic condition that affects collagen, leaving bones fragile and prone to fracture throughout life. There is currently no licensed treatment specifically approved to prevent fractures in adults with the condition, and patients often experience repeated fractures, chronic pain and long term disability. The trial tested a sequential treatment strategy commonly used in osteoporosis, where a bone building drug is followed by a treatment designed to preserve gains in bone strength. Although this approach successfully increased bone density in people with osteogenesis imperfecta, it did not reduce fracture rates, suggesting that treatment strategies effective in osteoporosis may not directly translate to rare bone diseases. Researchers did observe improvements in some quality of life measures among participants receiving the treatment, including reduced pain interference and improved mobility. However, fracture prevention remained unchanged, reinforcing the need for new approaches that target the fundamental properties of bone in osteogenesis imperfecta rather than density alone. The study was led by the University of Edinburgh and funded by the Medical Research Council and the National Institute for Health and Care Research. Aston University contributed clinical and academic expertise through Aston Medical School as part of the large international collaboration, which involved specialist centres across the UK and Europe. The study was led by the University of Edinburgh, with Aston University contributing clinical and academic expertise as part of a wider international collaboration involving multiple specialist centres across the UK and Europe. The research was funded by the Medical Research Council and the National Institute for Health and Care Research. Researchers say the findings provide important guidance for future research, helping to steer efforts towards treatments that focus on bone quality, strength and resilience in everyday life. They also highlight the value of large scale clinical trials in rare diseases, where learning what does not reduce harm is an essential step towards better care. The paper, Teriparatide Plus Zoledronic Acid for Osteogenesis Imperfecta, is published in JAMA. https://doi.org/10.1001/jama.2026.6889

Why disaster recovery in the Himalayas needs a rethink featured image

3 min

Why disaster recovery in the Himalayas needs a rethink

After five weeks of fieldwork across Nepal, Bhutan and Northwest India, Aston University researcher Dr Komal Raj Aryal is calling for a more locally grounded approach to resilience and post-disaster recovery in one of the world’s most hazard-prone regions. What happens after the headlines fade from a disaster? That question sits at the heart of new field research led by Dr Komal Raj Aryal, Lecturer in Crisis and Disaster Management at Aston Business School. After returning from a five-week research visit across Nepal, Bhutan and Northwest India, Dr Aryal says the evidence points to a troubling reality: many communities remain highly vulnerable long after major recovery programmes are supposed to have helped them rebuild. The trip brought together field visits, stakeholder consultations and community observations linked to ongoing UKRI, NERC and ISPF-supported research on earthquake risk, disaster governance, resilience and post-disaster recovery in the Himalayan region. The aim was not only to understand current conditions, but to ask why repeated losses continue despite years of international development assistance, scientific research and investment. Across the region, the research found that resilience is being undermined by a combination of persistent governance challenges, fragmented institutions, weak local preparedness systems, livelihood insecurity and mounting environmental pressures. In other words, recovery is not simply about rebuilding infrastructure; it is about whether communities are genuinely better equipped to cope with the next shock. This challenge is especially striking in places still living with the legacy of the 2015 Nepal earthquakes, where long-term vulnerabilities remain visible despite the scale of international support directed towards recovery and reconstruction. Reflecting on his findings, Dr Aryal said: “One of the most striking observations from the field is that many communities affected by the 2015 Nepal Earthquakes continue to face similar vulnerabilities today, despite significant international support allocated for recovery and reconstruction. This raises important questions about how disaster recovery is planned, implemented, and sustained over time.” The fieldwork also highlighted the growing complexity of future disaster risks in the Himalayas. Large-scale earthquakes do not exist in isolation; they interact with environmental degradation, cascading hazards, climate-related stresses and rapid urbanisation in fragile mountain settings. He added: “The Himalayan region is entering a period of growing uncertainty where environmental change, socio-economic inequality, weak governance systems, and seismic risks are becoming increasingly interconnected. There is an urgent need to rethink conventional development approaches and invest more seriously in locally grounded, community-centred resilience strategies.” For Aston University, this work reflects a broader commitment to international research on disaster risk reduction, resilience governance and humanitarian response across South Asia. Aston researchers are working with government agencies, local authorities, universities, emergency responders and humanitarian organisations to strengthen evidence-based approaches to preparedness and recovery. The findings feed into wider international debates about sustainable development, climate resilience, risk communication and the future of disaster governance in vulnerable mountain regions. They also underline the importance of moving beyond short-term recovery models towards approaches that are participatory, practical and rooted in local knowledge. Dr Aryal’s research emphasises the value of integrating community knowledge, participatory governance, youth engagement and long-term livelihood security into resilience planning. As future collaborations and policy discussions develop, these themes are likely to be central to how the region prepares for the risks ahead. The recent fieldwork is expected to inform future international research partnerships, policy dialogue and resilience-focused initiatives between the UK and South Asian partners.

Aston University economists say Prime Minister can reduce UK trade vulnerability with China visit featured image

2 min

Aston University economists say Prime Minister can reduce UK trade vulnerability with China visit

Greenland episode exposed UK’s lack of effective response to economic coercion from allies Research shows tariff retaliation would have cost the average UK household up to £324 per year Economists say China visit is “portfolio risk management” – diversification reduces vulnerability. The Prime Minister’s visit to China – the first by a British PM since 2018 – is an opportunity to reduce the UK’s vulnerability to economic coercion, according to new research from Aston University. A policy paper from Aston Business School’s Centre for Business Prosperity analyses the January 2026 Greenland tariff episode, when President Trump threatened and then withdrew tariffs on eight European countries. The researchers found that the UK had no good options: retaliation would have made Britain worse off, while absorbing the tariffs left Europe without credible deterrence. Director of the centre for business prosperity, Professor Jun Du, said: “The Greenland episode was a wake-up call. When your principal security ally threatens economic coercion, the old assumptions about who is safe and who is dangerous no longer hold. “The PM’s China visit should be framed as portfolio risk management – building diversified trading relationships that reduce the UK’s exposure to any single partner. Just as investors don’t put all their money in one stock, countries shouldn’t put all their trade into one basket. A UK with multiple strong partnerships is harder to pressure, whether the pressure comes from Washington or Beijing.” The research found that coordinated UK–EU tariff retaliation would have cost British households up to £324 per year – the worst outcome modelled. But the authors argue that Europe has untapped leverage elsewhere: the US runs a €148 billion annual services surplus with the EU, and mutual investment exceeds €5.3 trillion. Associate professor of economics and co-author, Dr Oleksandr Shepotylo, said: “Tariff retaliation fails because it hurts consumers and distorts the economy – the retaliator suffers similarly to the target. But Europe has cards it isn’t playing. Services, investment screening, and regulatory access are pressure points where Europe can respond effectively.” UK exports to China fell by 10.4% in the year to Q2 2025, with goods exports down 23.1% – the sharpest decline among major trading partners. The researchers argue that this closes off the UK’s largest alternative market at precisely the moment US reliability is in question. The paper identifies three priorities for UK policy: Recognise the permanent incentives behind US tariffs. US tariff revenue hit $264 billion in 2025. Trade negotiations alone cannot resolve revenue-driven policy. Build UK–EU coordination on non-tariff instruments. Services, investment, procurement, and regulation offer leverage that tariffs do not. Treat China engagement as portfolio risk management. Concentration in any single market creates vulnerability. Diversification is not about picking sides – it’s about resilience. Professor Du added: “The question for the Prime Minister is whether to use this breathing space to build resilience – or wait for the next Greenland.” To read the policy paper in full, click on this link:

View all posts