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Practical guides on terrain data and survey engineering: DEM, DSM and DTM, point clouds, orthophotos, cut/fill, stockpile volume and cross-section cubature.
What is a DEM? A Digital Elevation Model is a raster grid of ground elevations. Learn how a DEM is made and used, and how it differs from a DSM and DTM.
ReadDEM vs DSM vs DTM: what's the difference? Compare a Digital Elevation Model, Digital Surface Model and Digital Terrain Model, and see when to use each.
ReadWhat is an orthophoto? A geometrically corrected aerial image with uniform scale you can measure on. Learn how orthophotos and orthomosaics are used.
ReadWhat is a point cloud? A dense set of 3D points from LiDAR or photogrammetry. Learn the LAS and LAZ formats and how it becomes a usable surface.
ReadCut and fill is earth removed or added to reach a target surface. Calculate a sloped excavation or fill pad, then see why the reference surface matters.
ReadA stockpile volume calculator uses the cone formula: fair on a clean pile, wrong on flat-topped, wall-backed or uneven ones. Where it breaks, and what to use.
ReadCross-section cubature computes earthwork volume from sections along an alignment. Learn how stationing, end-area volumes and section drawings work in practice.
ReadGeoTIFF is a TIFF image with embedded georeferencing, used for DEMs and orthophotos. Learn what makes it 'geo', why it is standard and how to handle big ones.
ReadContour lines connect points of equal elevation. Learn how to read contours, what the interval and index lines mean, and how they are generated from a DEM.
ReadSlope and aspect are derived from a DEM: slope measures steepness, aspect the direction a slope faces. Learn why both matter for siting, drainage and planning.
ReadHillshade, or shaded relief, simulates sunlight on terrain to make its shape pop. Learn how sun azimuth and altitude create the effect and why it aids reading.
ReadA coordinate reference system (CRS) defines how coordinates map to the earth. Learn geographic vs projected systems, datums, and why matching the CRS matters.
ReadCompare the three earthwork volume calculation methods — surface-to-surface, cross-section and base-plane — and learn which one your job actually needs.
ReadA spreadsheet computing earthwork volume by average end area is real engineering. Here is where the station table stops being accurate, and where it can't help.
ReadA cut and fill grid plan turns a volume into a map: where material comes off, where it goes on, and how much at each square. Here is how to compute and read it.
ReadA mass haul diagram turns station quantities into one curve showing where material comes from, where it goes and how far it travels. Here is how to read it.
ReadEllipsoidal vs orthometric height: GNSS returns one, maps use the other, and the gap can exceed 30 metres. Learn the difference and stay consistent.
ReadGround Sample Distance (GSD) is the real-world size of one pixel. Learn how flight height sets it, how it limits DEM detail, and how much resolution you need.
ReadWatershed analysis explained: how flow direction, flow accumulation and stream order combine to delineate a watershed from a DEM — and where each step fails.
ReadComparing two surveys gives a difference map, but not every difference is real. Learn how change detection works and how to tell movement from survey noise.
ReadWhat is a DXF file? The file type survey and CAD software exchange drawings in — what is inside, why georeferencing is not, and how to fix one that opens wrong.
ReadViewshed analysis explained: how GIS software calculates line-of-sight visibility from a DEM, and why input data quality — not geometry — decides the answer.
ReadSun and Shadow Analysis on terrain: how solar position and shadow casting produce sunlight hours and insolation, plus the inputs that change the answer.
ReadIn-Situ vs Loose Volume: the survey says 10,000 m³, the trucks say 12,500 — both are right. Learn the three volume states, bulking and shrinkage.
ReadHow a haul road is designed: the alignment on the surveyed ground, the ruling grade, the typical section and the earthwork that comes out of the three.
ReadBench height, berm width and batter angle decide the overall slope angle — and the overall angle decides the stripping. How the three fit together in practice.
ReadBurden is the rock in front of a hole, spacing the gap between holes in a row. What each does, what goes wrong at the extremes, and why plan distance misleads.
ReadA TIN builds a surface from triangles connecting measured points instead of a regular grid. Learn how a TIN differs from a raster DEM and when each is right.
ReadWhat open pit mine surveying involves: the survey cycle, what gets measured, how volumes are reconciled and why survey figures and truck counts rarely agree.
ReadWhere the toe of a slope and the crest sit decides burden, berm width and set-out. Why plan distance misleads — and how the daylight line finds both edges.
ReadHow bench volumes are calculated between two survey surfaces or against a design: what the reference is, why bench boundaries matter and where errors come from.
ReadHow mine sites use drone surveys: flight planning and GSD, why ground control decides accuracy, what the deliverables are and which questions each one answers.
ReadA block model divides a deposit into a 3D array of blocks, each carrying estimated grade and density. Learn how one is built and how it is used.
ReadA DEM is not used once. Follow it through exploration, design, operations and closure — what changes at each stage and why one surface is never enough.
ReadA pit is never one surface. As-surveyed, as-designed, as-built and the ultimate shell all coexist — what each is for and what happens when they get confused.
ReadThe three slope angles an open pit is measured by, how each is taken off a survey, and why a face that passes can still sit in an overall slope that does not.
ReadWhere to cut a section in an open pit, how to space and orient them so the results are comparable, and what a section shows that a plan view cannot.
ReadWhat a photogrammetry run actually gives you — point cloud, DSM, DTM, orthomosaic and mesh — how LiDAR differs, and what happens to those outputs afterwards.
ReadPit slope angles: bench face, inter-ramp and overall slope angle — what each measures, how berms and ramps flatten the wall, and how to check a design.
ReadHow haul truck cycle time is built from loading, hauling, dumping and queuing, why ramp grade and length dominate it, and how it becomes a cost per tonne.
ReadHow Transverse Mercator (UTM), Lambert Conformal Conic and Albers Equal Area projections work, what each one distorts, and which to use for survey data.
ReadConvert DXF drawings to Shapefiles offline: what carries over (3D geometry, layer, name, CRS), what does not (text, blocks, hatches), and the steps.
ReadTurn a drone topographic survey into a lightweight CAD model: contours, crest and toe breaklines, a light TIN surface and LandXML — step by step, with checks.
ReadWhat to check before choosing drone survey software: processing vs analysis, cloud vs desktop, accuracy, volume bases, CAD exports, data size and cost.
ReadHow to choose GIS software for surveying, engineering and mining: terrain analysis, large rasters, point clouds, coordinate systems, CAD exchange, cost.
ReadWhere to download free DEM data — Copernicus DEM, SRTM, NASADEM, AW3D30, ASTER GDEM, USGS 3DEP, England LIDAR — and what to check before using it.
ReadLiDAR vs photogrammetry for drone surveys: how each one measures, which sees the ground under vegetation, where each fails, and which to use in mining.
ReadContours vs breaklines: contours are drawn from a surface, breaklines shape it. How each is made, why a surface needs breaklines, and what to deliver.
ReadHow to measure landfill airspace used and remaining, fill rate and compaction from drone surveys against the permitted design surface, step by step.
ReadPond volume calculator for sloped banks, then the DEM method: capacity to the spill level, volume at a chosen water level and a design storm.
ReadStripping ratio is waste moved per unit of ore. The formula, t/t versus m³/t, overall, incremental and break-even ratios, with a calculator.
ReadAn elevation profile is the ground's height plotted against distance along a line. How to create one from a DEM, what to read off it, and what distorts it.
ReadHow a LAS or LAZ point cloud becomes a DEM: ground classification, cell size from point density, DTM versus DSM, gaps, and the checks to run afterwards.
ReadHow repeat drone surveys track construction earthworks: cut and fill against design, change between surveys, cut/fill maps and what the numbers need.
ReadThe Manning equation gives discharge and velocity in an open channel from section, slope and roughness. Formula, n values, normal depth and a calculator.
ReadWaste dump design for open pit mines: lift height, angle of repose, berms, overall slope angle, foundation and capacity, with a geometry calculator.
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