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

3 min

New research partnership to develop biodegradable gloves from food waste for healthcare sector

Knowledge Transfer Partnership between Aston University and PFE Medical to develop a biodegradable clinical glove from food waste The gloves will provide a low-cost, convenient and sustainable alternative to the 1.4bn disposable gloves used in the NHS each year The innovation will reduce clinical waste and costs and help the NHS reach its net zero goals. Aston University and Midlands-based company PFE Medical are teaming up to create biodegradable gloves made from food waste for use in the NHS. They will offer a low-cost, convenient alternative to disposable gloves without compromising patient safety. More than 1.4bn disposable gloves are used by the NHS each year. They create large volumes of clinical waste which has both an environmental and economic cost. The Knowledge Transfer Partnership (KTP) project will develop a more sustainable alternative made from polymers derived from food waste such as orange peel, able to degrade naturally. The gloves will initially be for use during low-risk tasks such as ultrasound scans, rather than in more critical situations such as operating theatres. The gloves would be designed to not only reduce clinical waste and costs in the NHS, but also carbon emissions, helping the NHS reach its goal to be the world’s first net-zero health service. With most personal protective equipment (PPE) currently sourced from Chinese manufacturers, the goal is to develop a biodegradable glove that can be manufactured using a UK supply chain. The challenging project draws on Aston University’s expertise in sustainable polymer chemistry, centred at Aston Institute for Membrane Excellence (AIME). Aston University has one of the largest research groups of polymer chemists in the UK. The project will be led at the University by Professor Paul Topham, director of AIME, and Dr James Wilson, AIME associate member. The research team have chosen to focus on polymers from food waste in order to ensure that the final product can be manufactured sustainably. Most polymers are currently made from petroleum. Polymers made from food waste, ranging from fruit waste to corn or dairy products, have the potential for antioxidant and antibacterial properties if designed appropriately. The team will manipulate the polymer molecules so that they include the right monomers (the smaller units which make up the molecules) in the right location to achieve the properties they require. Critical to the success of the project will be PFE Medical’s commercial and clinical experience of taking new innovations into medical use. It will be the third KTP between Aston University and PFE, following on from successful projects to develop an automated endoscope cleaner, now in use across University Hospitals Birmingham NHS Foundation Trust (UHB). Professor Topham said: “At Aston University, we have a long history of working with industry, of translating fundamental research into solutions for real world problems. This project with PFE Medical provides us with that route, to take our science and engineering and make a difference to peoples’ lives. That’s exactly where, as researchers, we want to be.” Rob Hartley, CEO of PFE Medical, said: “Our previous KTP with Aston University was a phenomenal success, thanks to the brilliant team we had on board. I’m just as excited by this project, which is looking to solve an equally long-standing problem. If we can achieve our goal, then the implications are huge, going far beyond the NHS to all the other situations where people are wearing disposable gloves.” KTPs, funded by Innovate UK, are collaborations between a business, a university and a highly qualified research associate. The UK-wide programme helps businesses to improve their competitiveness and productivity through the better use of knowledge, technology and skills. Aston University is a sector-leading KTP provider, ranked first for project quality, and joint first for the volume of active projects. For further details about this KTP, visit the webpage: www.aston.ac.uk/business/collaborate-with-us/knowledge-transfer-partnership/at-work/pfe-medical.

2 min

Aston University’s Professor Gina Rippon wins British Psychological Society book award for The Lost Girls of Autism

Gina Rippon, professor emeritus of cognitive neuroimaging at Aston University, has won an award for her book, The Lost Girls of Autism The book won the 2025 British Psychological Society Popular Science Award It explores the emerging science of female autism, and examines why it has been systematically ignored and misunderstood for so long. The Lost Girls of Autism, the latest book from Gina Rippon, professor emeritus of cognitive neuroimaging at Aston University Institute of Health and Neurodevelopment (IHN), has won the 2025 British Psychological Society (BPS) Popular Science Award. The annual BPS Book Awards recognise exceptional published works in the field of psychology. There are four categories – popular science, textbook, academic monograph and practitioner text. With the subtitle ‘How Science Failed Autistic Women and the New Research that’s Changing the Story’, The Lost Girls of Autism explores the emerging science of female autism, and examines why it has been systematically ignored and misunderstood for so long. Historically, clinicians believed that autism was a male condition, and simply did not look for it in girls and women. This has meant that autistic girls visiting a doctor have been misdiagnosed with anxiety, depression or personality disorders, or are missed altogether. Many women only discover they have the condition when they are much older. Professor Rippon said: “It's such a pleasure and an honour to receive this award from the BPS. It’s obviously flattering to join the great company of previous winners, but I’m also extremely grateful for the attention drawn to the issues raised in the book. “Over many decades, due to autism’s ‘male spotlight’ problem, autistic girls and women have been overlooked, deprived of the help they needed, and even denied access to the very research studies that could widen our understanding of autism. This book tells the stories of these girls and women, and I’m thrilled to accept this prize on their behalf.”

3 min

New book from Aston University academic shows that Christmas tasks mostly fall on women

New book by Dr Emily Christopher shows differences in how household tasks are divided by men and women Book highlights that women tend to buy the Christmas presents and send cards Men often see women as being more thoughtful or having better knowledge of what people would like. A new book from Aston University’s Dr Emily Christopher reveals that when it comes to sending Christmas cards and buying Christmas presents, women are still mostly doing the work as they are perceived to have better knowledge of what people would like. Dr Emily Christopher, a lecturer in sociology and policy at Aston School of Law and Social Sciences, has recently published her book Couples at Work: Negotiating Paid Employment, Housework and Childcare, which look at how household tasks are divided by men and women and the reasons behind these divisions. The data for the book has been collated over an eight-year period with couples being interviewed twice to provide a robust set of results. It looks at how different sex parent couples combined paid work, housework and childcare. The research revealed how gender norms continue to shape how certain daily household jobs are divided. Women were more likely than men to clean the house, especially bathrooms, wash clothes and put clothes away. Men still tend to do tasks like mowing the lawn and DIY but now are also more likely to do the cooking and the grocery shopping. The research shows that the key to understanding how household tasks are divided lies in the meaning they hold for partners. With the festive season upon us, the book reveals that woman are largely responsible for the Christmas present buying and sending cards with 100% of those taking part in the research saying that women mostly carried out these tasks. This also included buying for the male partner's relatives. In instances where men had a 'helping' role in these tasks, this included being involved in the discussion or consulting on choice of presents, especially for children, with only a small minority buying presents for their own family. The data revealed that where women didn't choose and buy presents for their partners family, they were still involved in reminding their partners that this needed to be done or advising on choice of gifts, showing that women were still taking on the mental load of planning for the festive season. The book reveals that when men were questioned about why they didn't get involved in present buying, they drew on gender norms. Women were often described, by the men, as being more thoughtful or having better knowledge of what people would like. Men often described how family members wouldn’t receive presents at all if it relied on them. Although much of the gift giving and organising represented love and affection for the women, which many found enjoyable, many still saw it as work and expressed that they would like their partners' to be more involved. Dr Christopher said: “This book takes an in-depth look at the way in which everyday roles around the household are divided between men and women. “The research shows that over a period of eight years fathers increased their role in childcare tasks but this did not always extend to housework. “The pandemic was an opportunity to change how couples share housework but women were still more likely to carry out tasks like cleaning, washing clothes and putting clothes away and overwhelmingly remained responsible for the mental orchestration of family work.”

View all posts