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If you work in quarrying, mining, landfill, or earthworks, there is a good chance you have come across LSS — or at least heard someone mention it in a site meeting. It stands for Land Survey Software, and for many geotechnical engineers and surveyors, it has become an indispensable part of day-to-day work. This is the first in a new series called Software Spotlight, where we take a practical look at the tools that practising engineers actually use — not a dry list of features, but a genuine exploration of what they do, why they matter, and how to get the most from them.

LSS is developed by McCarthy Taylor Systems and has been a fixture in the UK and international survey and engineering sectors for decades. While it might not have the marketing budget of some of the larger CAD platforms, it has earned its reputation the hard way: by being genuinely useful for the kind of work geotechnical engineers do every day.

What Is LSS and Where Did It Come From?

LSS began life as a land survey processing package, initially developed to help surveyors handle the raw output from total stations and level books. In its earliest form, it was essentially a way of getting survey data into a usable digital format and producing plans and sections from it. Over the years, it has evolved substantially, and the modern version of LSS is a fully featured 3D terrain modelling and earthworks design platform with an impressive range of capabilities.

The software has a loyal following in the UK quarrying and civil engineering sectors in particular, where it is used for everything from calculating the volume of a quarry void to designing the final landform of a restored site. Part of its appeal is that it was built by people who understood surveying — the interface reflects the way surveyors and engineers actually work, rather than trying to shoehorn earthworks and terrain modelling into a platform originally designed for something else entirely.

What Data Can LSS Import?

One of the practical strengths of LSS is its ability to ingest data from a wide variety of sources. In the early days of digital surveying, data came almost exclusively from total station downloads — strings of coordinates that the surveyor had walked across the site, recording spot heights and feature codes as they went. LSS was built to handle that data natively, and it still does so very well. But the world of site data capture has changed enormously, and LSS has kept pace.

Today, LSS can import topographic surveys from total stations and GNSS receivers, point clouds from terrestrial and airborne LiDAR surveys, drone photogrammetry outputs (typically delivered as dense point clouds or mesh models), GPS track logs, and data exported from other platforms in standard exchange formats such as DXF, CSV, and LandXML. For geotechnical engineers, this is significant: it means you are not locked into a single data capture method, and you can combine data from multiple sources into a single model.

In practice, a typical quarry survey might combine a drone photogrammetry flight covering the working face area (where access is dangerous or impractical on foot) with a GNSS walking survey of the haul roads and stockpile areas, and perhaps a total station pick-up of the crusher and processing plant infrastructure. All of this data can be merged and processed in LSS to produce a unified surface model of the entire site.

Pro Tip: When combining drone and GNSS survey data, always check the vertical datum consistency before merging. A mismatch in datum reference — even a small one — can introduce systematic errors into your volume calculations that are very difficult to spot after the fact. Get the survey team to confirm that all data is referenced to the same benchmark before you start building the model.

Building Digital Terrain Models (DTMs)

At the heart of LSS is the Digital Terrain Model, or DTM. This is a mathematical representation of the ground surface, built from your survey data. In LSS, DTMs are constructed using a process called triangulation — the software connects your survey points into a network of triangles (a Triangulated Irregular Network, or TIN) that together describe the shape of the ground surface.

The quality of your DTM depends on two things: the quality of your input data and the decisions you make during the triangulation process. LSS gives you considerable control over both. You can filter out erroneous points, define breaklines to enforce accurate representation of features like drainage channels, bunds, and bench edges, and set constraints on the triangulation to prevent the software from creating spurious triangles across areas where there is no survey data.

This matters enormously in practice. A DTM that has been triangulated without appropriate breaklines can produce wildly inaccurate volume calculations, because the software will interpolate a smooth surface across areas that are actually sharply defined in the field. If you are modelling a quarry bench with a near-vertical face, for example, the software needs to know where that face is — otherwise it will interpolate a gentle slope across what is actually a ten-metre drop.

Cut and Fill Volume Calculations

Ask any quarrying or earthworks engineer what they use LSS for, and the chances are that volume calculations will be near the top of the list. The ability to accurately calculate how much material has been excavated, stockpiled, or placed is fundamental to almost every project in these sectors — whether you are monitoring progress on a landfill site, tracking extraction at a quarry, or managing earthworks on a road scheme.

In LSS, volume calculations are carried out by comparing two surfaces — typically an original ground surface (the pre-excavation or baseline survey) and a current ground surface. The software calculates the volume of material between the two surfaces, distinguishing between areas of cut (where material has been removed) and areas of fill (where material has been placed). The results can be reported in a range of formats and split by zone if required, which is particularly useful for complex sites where different areas have different licence conditions or material types.

From an engineering perspective, the real value is not just in the numbers themselves but in the ability to track changes over time. Most quarry and landfill sites carry out periodic surveys — typically quarterly or annually — and LSS makes it straightforward to build up a historical record of surface changes. This is invaluable for demonstrating compliance with planning conditions, reconciling measured volumes against weighbridge records, and identifying areas where the survey might need to be checked.

Quarry Reserve Calculations

For quarrying professionals, LSS offers specialist tools for reserve estimation that go beyond simple cut and fill. A quarry reserve calculation typically involves modelling the consented quarry boundary (the maximum permitted extraction envelope as defined by the planning permission), the current quarry floor and working faces, and any constraints such as buffer zones around site boundaries or sensitive receptors.

By building a model of the ultimate extraction limit and comparing it to the current survey, LSS can calculate the remaining reserve — the volume of material that can still be extracted within the consented boundary. This is a critical figure for operators, as it directly influences decisions about capital investment, planning applications for extensions, and long-term site management strategy.

The software also allows you to apply a recovery factor to account for processing losses, and to split the reserve by material type if you have geological mapping data available. For mineral planning purposes, being able to present a clearly documented reserve calculation — with the methodology, input data, and assumptions all recorded — is increasingly important, and LSS produces outputs that can be directly referenced in planning submissions and annual mineral reserves statements.

Slope and Bench Design

LSS includes tools for designing slopes and benches that reflect real engineering parameters rather than simply drawing lines on a plan. When you specify a slope design in LSS, you can define the bench width, bench height, batter angle, and overall slope angle, and the software will construct a design surface that respects these parameters throughout the model area.

This is particularly useful in quarrying and open pit mining, where the slope geometry directly affects both safety and economics. A steeper slope means more reserve is accessible, but it also means a higher risk of slope failure and greater demands on the drainage system. By modelling the slope design in LSS and comparing it against the geotechnical constraints established through the site investigation, engineers can make informed decisions about where the practical optimum lies.

Pro Tip: Always model both the design slope and a sensitivity case. If your geotechnical assessment recommends a 45 degree overall slope angle, model what the reserve looks like at 40 and 50 degrees as well. This gives the operator a clear picture of the commercial impact of the geotechnical constraints and makes for a much more productive conversation about risk and investment.

Restoration Modelling and Landfill Design

Restoration modelling is an area where LSS really comes into its own. Whether you are designing the final landform of a worked-out quarry, planning the restoration of a landfill site, or modelling the earthworks required to create a nature reserve from an industrial brownfield, the ability to build a proposed surface model and compare it against existing ground conditions is invaluable.

For landfill engineers, LSS is widely used to calculate remaining airspace (the volume available for further waste disposal), to design the capping layer profiles that direct surface water away from the waste mass, and to model the settlement that will occur as the waste degrades over time. The ability to track actual fill rates against the design model — and to update the model as new survey data comes in — makes LSS a genuinely useful operational tool, not just a one-off design exercise.

In restoration design, the software allows engineers to create smooth, naturalistic landforms that meet the ecological and visual requirements of the planning conditions while also satisfying the engineering requirements for drainage and stability. You can iterate rapidly through different design options, comparing the earthworks volumes and identifying the most cost-effective solution before any ground is moved.

Cross-Sections, Long Sections, and Contour Generation

Cross-sections and long sections are among the most fundamental outputs in geotechnical and civil engineering, and LSS generates them quickly and accurately from the DTM. You can extract sections at any position and orientation across the model, compare sections from different survey dates, overlay design profiles, and annotate them with engineering information before exporting to AutoCAD or printing directly from LSS.

Contour generation is equally straightforward. LSS produces contour plots directly from the DTM at user-defined intervals, and these can be exported in a range of formats for use in planning drawings, technical reports, or further CAD work. The contours generated by LSS from a well-constructed DTM are typically of higher quality than those generated by general-purpose CAD software working from the same data, because the LSS DTM respects the breaklines and feature codes that define the real shape of the ground.

3D Visualisation and Exporting to AutoCAD

LSS includes 3D visualisation tools that allow you to view your terrain model from any angle, drape aerial photography or orthophotos over the surface, and compare the existing and proposed surfaces visually. This is particularly useful for communicating with clients, planning authorities, and the public — a 3D model of the proposed restoration landform is far more effective in a planning meeting than a series of technical cross-sections that most non-specialists will struggle to read.

Exporting models to AutoCAD is a core workflow for most LSS users. The software can export surfaces, contours, sections, and design geometry in DXF or DWG format, which can then be opened in AutoCAD or MicroStation for further drafting work or integration with other project drawings. This interoperability is important in practice, because most engineering projects involve multiple software platforms, and the ability to move data between them without losing information or accuracy is essential.

Pro Tip: When exporting DTM surfaces to AutoCAD, export the triangulation mesh rather than just the contours if you intend to do further volume calculations in AutoCAD. Contour exports look good but are much less useful for subsequent analysis. The mesh export preserves the full geometric detail of the surface and gives AutoCAD the same data that LSS used for its calculations.

Advantages of Using LSS

LSS has several genuine advantages over more general-purpose platforms. First, it was built for this specific type of work — the workflows for terrain modelling, volume calculation, and earthworks design are intuitive because they reflect the way engineers and surveyors actually approach these tasks. Second, it is well-established in the UK quarrying and civil engineering sectors, which means that most clients, regulators, and specialist consultants will accept LSS outputs without question.

Third, the software is relatively affordable compared to some of the larger platforms — a factor that matters in a sector where many operators are running on tight margins. Fourth, McCarthy Taylor provides good technical support and regular software updates, and there is an active user community that shares knowledge and best practice.

From a geotechnical engineering perspective, the ability to integrate survey data, geological information, and design geometry within a single environment — and to produce outputs that meet the requirements of planning authorities, environmental regulators, and professional bodies — is a significant advantage. LSS does not try to do everything; it does a specific set of things very well.

Limitations and Common Beginner Mistakes

No software is perfect, and LSS has its limitations. The interface, while logical to experienced users, has a learning curve that can be steep for those new to terrain modelling software. The workflow is not as immediately intuitive as some modern platforms with drag-and-drop interfaces and real-time visual feedback, and beginners often find themselves building models that look plausible but contain errors that only become apparent when the volume calculations are checked against independent estimates.

LSS is also primarily a 2.5D terrain modelling tool — it models surfaces extremely well, but it is not a full 3D solid modelling platform. This means it cannot directly model underground features such as mine voids or complex geological structures in three dimensions. For those applications, you would need specialist subsurface modelling software such as Leapfrog or similar, and then integrate the LSS surface model with the subsurface data separately.

Finally, LSS is not a substitute for professional judgement. The software will calculate whatever volumes correspond to the surfaces you give it — it cannot tell you whether your survey data is accurate, whether your design is geotechnically sound, or whether the assumptions underpinning your reserve calculation are reasonable. These are engineering decisions that require professional experience and, in many cases, a site investigation and geotechnical assessment to support them.

Real-World Applications

To illustrate how LSS is used in practice, consider three typical scenarios from day-to-day geotechnical engineering work.

Quarry reserve reconciliation: A limestone quarry in the East Midlands carries out quarterly drone surveys of the active working area and annual total station surveys of the wider site. The survey data is processed in LSS, and the volume of material extracted since the previous survey is calculated by comparing the current and previous surface models. The result is reconciled against the weighbridge records to check for discrepancies — a difference of more than 5% triggers an investigation to identify whether there is a survey error, a material loss, or a weighbridge calibration issue. The LSS-generated reserve calculation is updated annually and submitted to the mineral planning authority as part of the operator’s Annual Minerals Review.

Landfill airspace monitoring: A non-hazardous waste landfill in the North West uses LSS to track fill rates and remaining airspace across a site that has been operational for over 20 years. The existing ground model was built from the original site investigation survey data and updated to reflect the progressive raising of the waste mass. Quarterly drone surveys are processed in LSS and the resulting airspace calculations are used to forecast the remaining operational life of the site — a critical input to the operator’s financial provisioning for post-closure management. The software is also used to design the final cap profile, ensuring positive drainage gradients away from the site boundary.

Infrastructure earthworks: On a major road scheme, LSS is used to process the initial topographic survey, build the existing ground DTM, and import the design formation level from the highway designer’s AutoCAD drawings. The software calculates the cut and fill volumes for each section of the scheme, produces cross-sections at 25-metre intervals for the tender documents, and generates a mass haul diagram that informs the earthworks contractor’s construction programme. Post-construction surveys are processed in LSS to verify that the earthworks have been completed within tolerance and to produce the as-built record drawings.

Key Takeaways

LSS is a mature, well-proven terrain modelling and earthworks design platform that has earned its place in the toolkit of geotechnical engineers across the quarrying, mining, landfill, and civil engineering sectors. Its strength lies in doing a specific set of tasks — building DTMs from survey data, calculating volumes, designing slopes and landforms, and producing cross-sections and contour plans — reliably and accurately. It is not the flashiest software on the market, but it is genuinely fit for purpose in a way that more general platforms often are not.

Understanding how to use it well requires both technical knowledge of the software and professional understanding of the engineering context — the two are inseparable. A volume calculation produced by LSS is only as good as the survey data that went into it and the engineering judgement applied to interpreting the results.

Five Beginner Tips for Learning LSS

1. Start with a small, well-defined dataset. When learning LSS, resist the temptation to jump straight into a complex real project. Use a small, clean survey dataset — ideally one where you already know what the answer should be — so that you can verify that your outputs are correct before applying the techniques to larger, more complex work.
2. Learn breaklines before anything else. Breaklines are the single most important concept in terrain modelling with LSS. Before you try to build your first real DTM, make sure you understand what breaklines are, when to use them, and how to define them from your survey data. Get this wrong and everything downstream will be wrong too.
3. Always check your DTM visually before running calculations. LSS has tools for viewing the DTM in plan and in 3D. Use them. Look for areas where the triangulation has gone wrong — unphysical spikes, inverted triangles, or flat areas in places where there should be relief. These are always symptoms of underlying data problems that need to be fixed before you run any calculations.
4. Keep a methodical record of your processing steps. LSS does not automatically document what you have done — that is your job. Develop the habit of writing down the steps you have followed, the data sources you have used, and the decisions you have made at each stage. If a client challenges your volume calculation six months after you produced it, you need to be able to reconstruct exactly how you got there.
5. Talk to the surveyors. The quality of your LSS model is largely determined by the quality of the survey data that goes into it. Build a good working relationship with the survey team, understand what they are measuring and how, and make sure they understand what you need from the data. A brief pre-survey discussion about point density requirements, breakline codes, and boundary definition can save hours of post-processing work.

Coming Next in Software Spotlight

In the next instalment of Software Spotlight, we will be turning our attention to QGIS for Geotechnical Engineers — the powerful, free and open-source GIS platform that is increasingly being used in site investigation, environmental assessment, and geological mapping workflows. We will look at how geotechnical engineers can use QGIS to manage spatial data, produce geological maps, integrate borehole information with surface topography, and produce publication-quality outputs for technical reports and planning submissions. If you are not already using GIS in your day-to-day work, the next Software Spotlight might just change that.

Bridge and Bedrock covers practical geotechnical engineering for practitioners at every stage of their careers. If you found this article useful, subscribe to receive new posts directly to your inbox — and feel free to share with colleagues who might benefit.