Why specification matters

Topographical surveys are not off-the-shelf products. They are tailored to suit a specific purpose, whether that is planning, detailed design, or construction.

A common issue is assuming any topographical survey can be reused for multiple purposes. In reality, a survey designed for one task may lack the detail or accuracy needed for another. This can result in needing additional surveys later on, delays to design work and avoidable extra costs.

A well-planned specification at the start helps ensure the survey is fit for purpose and delivers value throughout the project lifecycle.

The five key elements to define in your survey brief

When you are briefing a surveyor, there are five core elements to consider:

1. The survey area

Your site boundary is not always enough to define the area you need to be surveyed. You may also need access routes, nearby buildings, trees or utilities which may affect the design. Including a small buffer zone around your site can prevent gaps in critical data too.

2. Level of detail

More detail means more time, which means higher cost. For example, a simple, flat site may only need widely spaced ground levels, while complex terrain requires much denser data. If you are clear about what you actually need, this will help you avoid paying for unnecessary detail, however, you should consider how your future needs might evolve as well as immediate requirements, to get the best value from your survey.

3. Accuracy

Levels of accuracy should match how the survey will be used. Early planning can work with rougher data, but detailed design needs much higher accuracy. A useful rule of thumb is that the larger the drawing scale, the higher the required accuracy.

4. Grid and datum

This defines how your survey relates to real-world coordinates and levels. ‘Grid’ refers to how positions are measured across the ground and ‘datum’ is the reference point used for height, usually relative to sea level. Using the right grid and datum ensures that your survey lines up with other data, that designers and engineers are working consistently and that measurements are accurate across the whole project. A survey control network should be installed when your topographical survey is measured – this network can then be used throughout your project to ensure consistency and reproducibility.

5. Deliverables

Think about how you will use the data:

• CAD drawings for design?
• PDFs for reporting?
• 3D models for visualisation?

The cost of getting your topographical specification wrong

Over-specifying wastes money but under-specifying creates risk. The most cost-effective approach is to align the survey specification closely with your intended use, and to involve your survey provider early. A good surveyor will always help you strike the right balance.

You can download our full client guide on topographical surveys for detailed advice on defining your survey requirements and avoiding common pitfalls. The Survey Association publishes a range of guidance notes on different aspects of surveying – access all our guides here.

The post Getting the specification right for your topographical survey: how to avoid costly survey mistakes appeared first on The Survey Association.

A topographical survey is a detailed measurement of the features within a site that gives you a clear picture of what already exists on the ground before any design or construction begins. It captures natural elements, like ground levels, trees and vegetation, and man-made features, such as buildings, roads, kerbs, walls and visible drainage features, for example gullies, manhole covers or downpipes. 

Information from the survey can be delivered in several formats, including CAD drawings, a PDF plan, a 3D model or a point cloud.

When do you need a topographical survey?

Topographical surveys are used at multiple stages of a project, from early planning through to completion. They can be used for planning residential or commercial developments, roads, railways and infrastructure. Useful for assessing boundary lines, rights to light or party wall issues, they can also be commissioned to support land sales or redevelopment of sites, or to monitor ground movement and any structural changes.

Topographical surveys can also create accurate records of a site at a specific point in time, which can prove invaluable later on in a project’s lifecycle.

Why are topographical surveys so important?

If designers and engineers do not have an accurate understanding of a site, they may make mistakes in design. This can lead to construction delays and ultimately unexpected and increased costs.

A topographical survey helps reduce these risks by ensuring everyone involved in the project is working from the same reliable data.

One important thing to know about topographical surveys

The survey needs to be properly specified, as a survey that is suitable for one purpose, for example outlining buildings for demolition, may not be detailed enough for another, which might need very precise design work. Getting this right at the outset will save time, avoid unnecessary costs and ensure the survey delivers real value throughout your project. A reputable survey practitioner (such as a TSA member company) can help you decide on the correct specification for your requirements.

You can learn more in our full client guide, which explains how to specify a topographical survey, what to ask for, and how to get the best results for your project. The Survey Association publishes a range of guidance notes on different aspects of surveying – access all our guides here https://www.tsa-uk.org.uk/resources/downloads/

The post What is a Topographical Survey (and do you need one?) appeared first on The Survey Association.

For many members, the AGM, annual Conference, workshops and resources are the visible outputs of TSA’s work. Less visible, but equally important, is the dedicated group of professionals who volunteer their time to ensure the Association continues to deliver value for its members and champion the geospatial surveying profession.

Providing leadership for the profession

Made up of representatives from member companies across the UK, TSA Council provides strategic direction for the Association. Council oversees the work of TSA’s committees – Public Relations (PR), Membership & Internal Affairs (MIA), and Technical and Finance – ensuring that projects, initiatives and decisions align with the Association’s vision and objectives.

Much of the work undertaken by these committees is highly specialised, but Council maintains an overarching view, bringing together activity from across the organisation to ensure TSA continues to grow, evolve and meet the needs of its members, from continually raising standards and tackling equipment theft to driving education initiatives.

Raising the profile of geospatial surveying

A key focus for Council at present is TSA’s national marketing campaign, designed to promote awareness and recognition of the importance of geospatial surveying.

Despite the vital role surveyors play in construction, infrastructure, utilities, property and environmental projects, many outside the profession remain unaware of the expertise involved and the value geospatial surveying brings to successful project delivery.

A dedicated task force from within Council is helping to steer this long-term campaign, ensuring it not only promotes the profession but also supports wider objectives around recruitment, education and industry recognition. By increasing awareness amongst decision-makers, educators, young people and the public, TSA aims to strengthen the future pipeline of talent entering the profession.

Planning months – and sometimes years – ahead

One of the most significant responsibilities of Council is overseeing TSA’s major events programme.

To ensure members can enjoy well-organised events, Council planning will begin at least nine months in advance. At today’s meeting, discussions will include preparations for TSA’s annual Conference in November, one of the profession’s flagship networking and development events.

In fact, by the time delegates arrive at the Conference later this year, planning will already be underway for 2027’s AGM. This continual cycle of preparation ensures that every event maintains the high standards members have come to expect from TSA.

Whether selecting speakers, reviewing budgets, considering member feedback or identifying future opportunities, Council is constantly looking ahead, typically working six to nine months in advance to ensure activities are delivered successfully.

Upholding standards and supporting members

At its heart, TSA exists to benefit its members and promote excellence throughout the geospatial profession.

Council plays a critical role in maintaining the standards that TSA is known for. It considers issues affecting members, supports the work of the committees, guides policy and strategy, and helps ensure that membership continues to represent a mark of professionalism and quality within the industry.

This responsibility requires careful consideration, collaboration and a commitment to doing what is best for the Association and its members.

A significant commitment by leadership

Serving on Council is a considerable undertaking. Council members balance their TSA responsibilities alongside the demands of running businesses, leading teams and delivering projects within their own organisations.

Yet they continue to dedicate their time, expertise and energy because they believe in the value of TSA and the importance of supporting the profession’s future.

The success of the Association relies heavily on this willingness to contribute, collaborate and think beyond individual business interests for the benefit of the wider surveying community.

As the Council meets today at the University of Warwick, its members will once again be looking ahead, planning future events, shaping strategic initiatives and guiding the national campaign to raise the profile of geospatial surveying.

While Council’s work may often happen behind the scenes, its impact reaches every member of The Survey Association.

Find out more about TSA’s Council members here.

The post The power of leadership: TSA Council in action appeared first on The Survey Association.

For the geospatial surveying profession, that sense of community is one of the defining strengths of The Survey Association (TSA). Established in 1979, TSA continues to support and represent surveying companies across the UK, bringing together businesses, educators, suppliers and industry leaders with a shared goal: advancing the profession and securing its future.

Bringing people together in a community

Surveying is a profession built on precision, expertise and innovation, but it is also powered by people. The opportunity to share experiences, discuss challenges and learn from peers is invaluable in a profession that continues to evolve through emerging technologies, changing client expectations and increasing demands for skilled professionals.

TSA has long recognised the importance of creating opportunities for meaningful collaboration. Through conferences, webinars, stakeholder events and networking opportunities, members gain far more than technical knowledge; they become part of a professional network that encourages growth, innovation and mutual support.

Raising the profile of the Geospatial Surveying community

One of the biggest challenges facing the profession is ensuring that decision-makers, educators and young people fully understand the value that geospatial surveyors bring to the built environment.

From infrastructure and construction projects to environmental management and digital twins, accurate geospatial data underpins informed decision-making. Yet many outside the profession remain unaware of how fundamental surveying is to successful project delivery.

TSA has increasingly focused on raising awareness of the profession and communicating its importance to wider audiences, working with partners, educational institutions and professional bodies. Now, the association is helping to ensure that geospatial surveying receives the recognition it deserves through a national marketing campaign.

Inspiring future talent

Like many sectors, surveying faces an ongoing challenge in attracting the next generation of professionals. Encouraging young people to consider careers in geospatial surveying is essential if the industry is to continue growing and innovating.

The profession offers diverse and rewarding career opportunities, combining technology, problem-solving and real-world impact. Through its support of education, training initiatives and engagement with students, TSA continues to play an important role in helping future surveyors discover the possibilities available within the sector.

More than membership

While practical benefits such as industry guidance, business support, professional development resources and networking opportunities are important, the real value of TSA membership lies in belonging to a collective voice for the profession.

In a rapidly changing world, no business succeeds in isolation. The ability to connect with others, share expertise and work towards common goals has never been more important.

To learn more about becoming a member of The Survey Association, visit: https://www.tsa-uk.org.uk/membership/

The post Why community matters more than ever in the geospatial profession appeared first on The Survey Association.

The principle behind photogrammetry

If you walked around a building and took digital photos from lots of different angles, each image would capture a slightly different view. Photogrammetry software compares these different images, identifies common features across them, and uses this information to calculate their precise position.

A useful way to think about it is comparing it to how people see the world. Each of our eyes sees a slightly different view and our brain combines them to create depth. Photogrammetry does the same thing, but instead of two images, it might use hundreds or even thousands.

The three key steps involved in the photogrammetry process

While the process is highly technical behind the scenes, it can be broken down into three main stages:

1. Understanding the camera

Before anything else, the software needs to understand how the camera “sees” the world. Every lens introduces small distortions, so the system accounts for these to ensure measurements are accurate. This step is often called camera calibration.

2. Matching images and building the model

Next, the software searches across all the photos to find matching features, points that appear in multiple images.

By linking thousands of these points together, it builds a 3D framework known as a point cloud. This forms the foundation of the final model.

3. Placing it in the real world

Finally, the model is tied to real-world coordinates using surveyed control points.

This step, known as georeferencing, is what turns a visual model into accurate, usable survey data that designers and engineers can rely on.

Why overlap matters in photogrammetry

One of the most important requirements in photogrammetry is image overlap. Each digital photo must share a significant amount of common ground with the next, typically 60-80%. If there isn’t enough overlap, gaps can appear in the data, accuracy is reduced and the final model may be unreliable. So, good data capture is just as important as good processing.

Why this matters for clients

Understanding the basics helps you ask the right questions and ensures you get data you can trust.

The process may happen behind the scenes, but the impact is huge. The quality of the final output depends on professional planning, coverage, and control, not just the software used.

Photogrammetry is now more accessible than ever, but producing reliable, accurate survey results still requires professional expertise.

For detailed guidance on workflows, accuracy, and specifying photogrammetry surveys, download the full client guide from The Survey Association website.

The post How photogrammetry works (without the jargon) appeared first on The Survey Association.

Driving professional excellence

The Survey Association provides a dynamic and forward-thinking community where organisations can collaborate, share expertise, and collectively raise standards across the profession. Membership of TSA demonstrates commitment to quality and signals that your organisation consistently performs to the highest professional standards and adheres to best practice.

Network, collaborate and grow when you join The Survey Association

One of the most valuable aspects of TSA membership is the opportunity to connect with like-minded professionals across the geospatial sector. Members enjoy a packed calendar of networking opportunities throughout the year, including:

• Exclusive events at prestigious venues such as Wembley, Twickenham, and Silverstone
• Inspirational guest speakers
• Informal and formal opportunities to build relationships and collaborate

These events are powerful platforms for learning, sharing ideas, and building lasting business connections.

Invest in your team with CPD and training

Continuous professional development is essential in maintaining high standards and keeping pace with change across the construction industry. TSA supports this by offering:

• Access to valuable CPD opportunities
• Discounts at The Survey School, helping to train and develop talent
• Reduced rates on software licences from Leica,Trimble and Topcon
• PI Insurance scheme tailored to TSA members

Membership that fits your organisation

Whether you are a small specialist team, a large surveying firm, or involved in the wider geospatial world, TSA offers a range of membership levels to match your eligibility so you can access the correct category for your business.

Raising the profile of geospatial surveying

At a time when the role of geospatial has never been more important, TSA is leading a national marketing campaign to reposition surveying as a strategic, indispensable function within the construction industry. The campaign champions the value of geospatial surveying and elevates the profession as a whole.

If you want to strengthen your professional credibility, build meaningful connections and support the future of geospatial surveying, find out more about how to join TSA today. https://www.tsa-uk.org.uk/about-tsa/contact/

The post Join The Survey Association, the community shaping the future of geospatial surveying appeared first on The Survey Association.

The conversation should be all about what spatial evidence clients need, in order to make the right decision.  A unified national campaign is underway to help reposition geospatial surveying from a technical support service to a critical evidence-based profession.

Client Guides: a practical resource for professionals and clients

TSA’s Client Guides are not intended to overwhelm with highly technical details, but instead they provide concise, accessible introductions to a wide range of surveying disciplines. If you’re an architect, engineer, planner, project manager or simply a client looking to understand what you need and why, these guides offer a great starting point.

Each guide is carefully structured to answer the questions you’re most likely to ask:

• What is this type of survey?
• When and why is it needed?
• What equipment and techniques are used?
• What regulations or procedures apply?

This practical approach helps demystify surveying, giving you confidence when specifying requirements, managing risk, and engaging with surveying professionals.

A wide range of topics

TSA’s collection of Client Guides reflects the diversity of the geospatial surveying sector. From traditional ground-based methods to cutting-edge technologies, the guides cover subjects including:

• Topographical surveys
• Measured building surveys
• Setting out surveys
• Hydrographic surveys
• Aerial LiDAR
• Photogrammetry

…and many more.

If you’ve already explored our recent blog on photogrammetry, you’ll know how powerful modern surveying methods have become. The full range of TSA Guides reveals how different survey techniques work together to support everything from construction and infrastructure to environmental monitoring and asset management.

Why download a TSA Client Guide?

Reliable information can be difficult and time-consuming to sift through. TSA’s Client Guides offer a trusted shortcut, developed by geospatial experts and grounded in real-world practice.

By downloading a Guide, you can:

• Clarify your project requirements before commissioning work
• Avoid costly misunderstandings by knowing what to expect
• Understand the scope and limitations of different survey methods
• Stay aware of relevant standards and procedures
• Make better, more informed decisions

Whether you’re at the early planning stage or already working on a project, having the right information at your fingertips can make a huge difference.

Designed for easy access

All TSA Client Guides are available as downloadable PDFs, making them easy to access, share, and refer back to whenever you need them. They’re ideal for quick reading but also useful as ongoing reference documents throughout the lifecycle of a project.

If you’ve found value in learning more about photogrammetry, why stop there? There’s a whole library of guidance waiting to be explored. Each guide offers insights into a different aspect of surveying and its role in delivering successful outcomes.

Visit the TSA downloads section and discover the full range of Client Guides

Take a few minutes to browse. You may find exactly the information you didn’t realise you needed.

The Survey Association (TSA) is committed to promoting best practice and improving understanding across the surveying profession. Our Client Guides are just one way we’re helping to bridge the gap between technical expertise and practical application.

Discover TSA’s Client Guides here https://www.tsa-uk.org.uk/resources/downloads/

The post Unlock the value of geospatial surveying expertise: explore TSA’s free Client Guides appeared first on The Survey Association.

Photogrammetry is one of those technologies many people rely on without realising it. If you’ve looked at a detailed aerial map, explored a 3D model of a site, or reviewed a drone survey, there’s a good chance photogrammetry was behind it.

What is photogrammetry?

At its simplest, photogrammetry is the process of using digital photographs to measure and map the real world. By taking multiple, overlapping images of the same area from different angles, specialist software can identify shared features and calculate their size, shape and position. The result is an accurate, measurable representation of the environment, ranging from 2D plans to full 3D models.

Put simply, photogrammetry turns digital photos into reliable, usable data. While the principle has been around for over a century, advances in digital cameras, drones, computer power and processing software have transformed what is possible to achieve, making photogrammetry faster, more accessible, and more cost-effective than ever.

Why is photogrammetry important?

Photogrammetry is widely used across construction and engineering, planning and design, asset management, heritage, and environmental monitoring. Its main strength is the ability to capture large amounts of data quickly and safely. In many cases, information can be collected remotely using drones or aircraft, reducing the need for surveyors to access difficult or hazardous areas.

For clients, this means faster site data capture, reduced disruption and safer workflows.

It isn’t just used for large scale areas – it can also be used to capture artefacts and objects in high detailed in controlled conditions with DSLR (Digital Single-Lens Reflex) cameras.

Does photogrammetry just produce images?

Photogrammetry produces measurable survey data that can be used throughout a project. This can include:

• Orthophotos – accurate aerial images you can measure from
• 3D meshed/textured models – ideal for visualisation and analysis
• Point clouds – dense datasets similar to laser scanning

With the correct geospatial survey practices where survey control, GCPs (Ground Control Points) and targets, are deployed – these outputs provide visual clarity and technical accuracy, helping teams make better decisions from the outset.

The resulting 3D data can be combined with 3D laser scan point cloud data and traced to produce CAD drawings, or help build 3D models in software like Revit– ready for use in design and planning.

What are the benefits of photogrammetry?

Photogrammetry offers several key advantages:

• Non-intrusive data capture (no digging or physical contact)
• Rapid collection of large datasets
• Access to areas out of visual line of sight from the ground for laser scanners
• Highly detailed, visual outputs
• A permanent digital record that can be reused over time if survey control is used

However, it’s important to recognise that results depend on good planning, high-quality imagery, and professional geospatial survey expertise. When a drone is deployed, it is important that the pilot is licenced, experienced, has gained all the relevant permissions and authorisations, and fully is insured. While the technology is more accessible, producing reliable, survey-grade data still requires experienced practitioners.

Why should you care about photogrammetry?

For clients and stakeholders, the value is straightforward. Photogrammetry gives you rich, visual data you can measure, analyse and rely on throughout your project. Used correctly, it can improve understanding, reduce risk, and support better decision-making, from early planning to final delivery.

This is just an introduction. For detailed guidance on specifications, workflows and procurement, download the full client guide from The Survey Association website.

The post What is Photogrammetry, and why should you care? appeared first on The Survey Association.

At TSA, we remain firmly committed to supporting our members and leading efforts to address this issue. Over the past decade, we have played a central role in driving the national response to survey equipment theft, and we are pleased to share positive progress, while recognising there is still a way to go.

Strengthening the national response

Building on almost a decade of evidence gathering with SmartWater/DeterTech, in 2025 TSA started to directly support the work of the National Construction and Agriculture Theft Team (NCATT), a specialist operational police unit established in 2023.

NCATT is unique as the UK’s only fully industry-funded specialist police unit dedicated to tackling Organised Criminal Groups (OCGs) involved in the theft of construction and agricultural equipment. Bringing together officers from across the country with expertise in rural crime and equipment theft, the team is small but highly effective.

In a relatively short time, NCATT has:

• Improved coordination between police forces nationwide
• Enhanced intelligence sharing across regions and sectors
• Delivered operational support and training
• Conducted investigations into high-value machinery theft
• Built strong partnerships with industry and European law enforcement

Importantly, NCATT has been working directly with TSA members, not only supporting individual cases of theft but also helping to unite resources across the UK to actively pursue organised crime gangs.

Real progress with a persistent challenge

There is encouraging news. NCATT and local police teams have achieved record-breaking seizures of stolen equipment, alongside arrests and significant cash recoveries across the UK. These outcomes demonstrate that coordinated, intelligence-led policing is making a real difference.

However, the national and international illicit demand for machinery remains high and continues to drive organised criminal activity, meaning that while enforcement efforts are delivering results, the risk of thefts remains.

A collaborative approach

The work of NCATT highlights the importance of a three-pronged approach:

• Prevention: strengthening security and awareness
• Enforcement: targeting and disrupting organised crime
• Collaboration: sharing intelligence and working together

By focusing on these areas, NCATT plays a critical role in safeguarding our sector, protecting vital infrastructure, and supporting the hardworking businesses that keep projects moving across the UK.

What to do if theft occurs

If you experience theft, acting quickly and following the correct process is essential to maximise the chances of recovery:

1. Report the theft immediately

Report the theft to the police force where the incident occurred. This is critical as only the relevant force can formally investigate and circulate the equipment as stolen on police systems. If your equipment has live tracking and you are not receiving a timely response, contact NCATT immediately.

2. Notify key partners

Email the equipment manufacturer and NCATT via ncatt@northumbria.police.uk to ensure NCATT is aware and can assist and the manufacturer can flag the equipment on their systems. For Leica Geosystems equipment, also notify uk.support@leica-geosystems.com

3. Provide full details

Use the subject line: “Survey Theft Notification” and include:

• Make and model
• Serial number
• Approximate value
• Date of theft
• Location of theft
• Police crime reference number

Please note that online reporting reference numbers cannot be acted upon until a formal crime number is issued by the police.

Moving forward together

While the challenge of survey equipment theft is far from over, the progress being made through collaboration with NCATT is significant and encouraging. By continuing to work together we are building a stronger, more resilient response.

The post Working together to tackle survey equipment theft appeared first on The Survey Association.

At the stakeholder event held at Twickenham as part of last month’s AGM, there was a clear and shared consensus: our profession needs greater visibility, clearer messaging, and a stronger level of public understanding.

The overarching aim of the campaign is to reposition geospatial surveying as a strategic, indispensable function across industry. We need to shift perception from viewing geospatial surveying as a technical trade, to recognising it as a professional consultancy discipline. Surveying should not be seen simply as a cost to a project, but as the strategic foundation upon which everything else is built.

A task force to drive change

Working in collaboration with O agency, we have now established a dedicated Task Force that will shape both the vision and the strategic outputs of the campaign. This group will be responsible for developing a clear 12-month plan that will form the foundation of the initial campaign strategy.

The campaign is to be built across five strategic pillars:

1. Building awareness and visibility
2. Regulations and standards
3. Industry alignment
4. Talent pipeline and education
5. Commercial value shift

To deliver meaningful change, we must influence policy and regulation, drive a shift in procurement behaviour, and build a sustainable and resilient talent pipeline for the future of the profession.

Securing the right level of funding will be critical to the campaign’s success, and the scale of its impact will depend on the level of support received from our members. Encouragingly, we are already in discussions with a number of organisations that are keen to get involved at an early stage, with strong interest and clear intent being demonstrated.

Find out more by attending the presentation by Oliver Viney at GEO Business on 3^rd June at 12:00 on the Surveying & Capture Stage. Please do get in touch if you would like to know more or get behind this campaign.

The post Raising the profile of geospatial surveying: building momentum for change appeared first on The Survey Association.