Digital Aerial Photography & LiDAR Surveys integrates a high-resolution aerial camera (80/100 megapixel) which can capture imagery at a resolution of 5 -15cm GSD with an IMU, GPS and a LiDAR (Light Detection and Radar) system on an aerial platform.  The LIDAR System pulses hundreds of thousands laser lights per second, each laser light having multiple returns.  A sensor measures all the reflected pulses, with the measured difference then in laser return time and wavelengths enabling the accurate generation of a digital 3D representation of the target.  The LiDAR Point Density (LPD) per square meter can be captured at anything from 1 – 25 points per square metre.  LiDAR can penetrate densely vegetated areas (such as a forests), and hence typically capture bare earth terrain models beneath the forest, as well as the internal structure of the forest itself.  The nett effect of this integrated airborne system enables the survey acquisition of up to 100 square kilometres of target area per day.  This integrated technology derives the most accurate digital terrain models on medium – large greenfield areas / corridors.

Consequential products can be delivered through the filtering and classification of all the “above -ground” data into point cloud LAS sub-classes such as buildings, infrastructure, power-lines, water, vegetation etc., – which together with the high resolution and spatially accurate ortho-imagery derived enables more detailed analysis, interpretation and interrogation capabilities to our Clients.

Trail Surveys provides an extensive range of tailor-made remote sensing survey products, stand-alone or in combination with any of our other survey services to affect the most time and cost-effective solution to our Clients.   Our remote sensing survey data can be provided in virtually any format, any geographical datum, and compliant to any technical specification you desire.


  • Most time and cost-effective survey methodology to survey medium – large areas

  • Derive engineering grade accuracy survey data products (Relative Accuracy – high, Absolute Accuracy – medium to high).

    • Planimetric Accuracy – from 8cm (5cm GSD) up to 20cm (15cm GSD) RMSE
    • Vertical Accuracy – from 5cm (5cm GSD) up to 12cm (15cm GSD) RMSE
  • LiDAR can penetrate dense vegetation – enables engineering grade accuracy survey of the ground (DTM) under tree canopies (forests) and densely vegetated areas;

  • Multiple LiDAR return capabilities renders a point cloud which can easily be sub-classified into different LAS classes such as ground / non-ground / buildings / infrastructure / water / powerlines / vegetation etc. for increased analytical and design capabilities in downstream applications;

  • Our survey data deliverables can easily be integrated with all engineering design – and cad software


Typical applications will comprise the following (but not limited to):

  • High Resolution Georeferenced Ortho-imagery of small – large areas

  • Engineering Grade accuracy DTM and contour generation

  • Services and Infrastructure Development Projects (Prelim and Final Design) such as:

    • Road Corridor Mapping (Greenfields and as-built scenarios);
    • Powerline Corridor Mapping (Greenfields and as-built scenarios);
    • Pipeline Corridor Mapping (Greenfields and as-built scenarios)
  • Detail topographical mapping of any small – large area for civil and structural construction purposes;

  • Volumetric Surveys (stockpiles, open cast mining areas etc.)

  • Dam Basin / Hydrological / Flood Line Determination surveys


Trail Surveys offers the following typical survey deliverables for remote sensing surveys:

Survey Control Co-ordinate List (only) Soft Copy File MS Excel PDF ASCII Txt
Co-ordinate List included in Survey Report Soft Copy File MS Word PDF
Separate Survey Control Report Soft Copy File MS Word PDF
Remote Sensing Surveys Digital Terrain Model (DTM) Point Data ASCII Txt (AutoCAD) .DWG .DXF
Triangles / Surface File Modelmaker.tot Civil Designer.cdm Land XML
Tile Index (If Applicable) (Microstation) DGN (AutoCAD) .DWG .DXF
Contours 3D Un-smooth, Labelled (Microstation) DGN (AutoCAD) .DWG .DXF
Contour 2D Heat Map JPEG PDF
Ortho-Imagery Georeferenced Ortho-Imagery ECW GEOTIFF JPEG
Tile Index (If Applicable) (Microstation) DGN (AutoCAD) .DWG .DXF
LiDAR Data Unfiltered LAS Pointcloud ASCII LAS
LAS: Ground + Non-ground LAS ASCII Txt
LAS: Services LAS ASCII Txt
LAS: Buildings LAS ASCII Txt
LAS: Vegetation (Primary) LAS ASCII Txt
LAS: Vegetation- Sub-classes LAS ASCII Txt
LAS: Full Intnl Standard LAS ASCII Txt
Videos Fly-through Video AVI MP4 WMF
Point Cloud Processed Point Cloud Data ASCII Txt LAS .BIN
Detail Line Mapping (Vector) 2D Drawing (Microstation) DGN (AutoCAD) .DWG PDF
Long Sections (Microstation) DGN (AutoCAD) .DWG .DXF
Cross-Sections (Microstation) DGN (AutoCAD) .DWG .DXF
Sections (Other) (Microstation) DGN (AutoCAD) .DWG .DXF


We understand that every project, site and client is different – as are their expectations of the required survey deliverables.  In order to “sharpen the pencil” and offer you the most cost and time effective geomatics solution, fit for the purpose you require the survey, we would need to acquire the following information from you:

  • Location of the survey – ideally a “Google Earth Placemark” send to us in kml/kmz format

  • The purpose of the survey – this serve as an indication of the required level of accuracy required

  • Required accuracies (planimetric and vertical)

  • Specific detail which need to be surveyed

  • In the case of a LiDAR survey – required LAS classification (typical run-of-the-mill applications require only Ground and Non-Ground LAS classes)

  • Details on the presentation of the survey data

    • Hardcopy / Softcopy
    • CAD Specifications / Drawing Layout
    • Digital data formats required for integration into your design / cad software
  • Specific logistic constraints getting access to the specific area of interest

  • SHEQ Requirements (Medicals / inductions / onboarding / PPE / Mine-ready vehicles etc)

  • Schedule / Program – Should a staggered delivery be required we can work with you to provide critical data at key dates throughout your project.