Meaning
Geospatial analysis techniques combine successive topographical surveys to calculate physical volume changes across an industrial site over time. Utilizing differential elevation mapping allows engineers to track the movement of bulk material during excavation and soil grading operations. The technique measures the height differences between a baseline survey and subsequent scans to map where soil is being deposited or removed.
Surface Comparison
Data processing software subtracts the elevation values of the first scan from those of the second scan to produce a grid of change values. Positive numbers show fill areas, and negative numbers show cut areas. This map guides the heavy machinery operators on where to move earth next.
Drone Guidance
Unmanned aerial vehicles fly pre-programmed flight paths at fixed altitudes to collect high-resolution images for the survey. These flights are conducted before excavation begins and after each major shift of earth. Relying on drones reduces the time required for ground crews to walk the site with survey poles, which increases safety on active construction zones.
Volume Derivation
Accurate calculation of stockpiled material is necessary for estimating project completion times and verifying contractor billing. By integrating the elevation differences over the total surface area, the software provides a precise volume of soil moved. This is compared against the supplier’s initial estimates to identify any discrepancies before final payments are issued.
Using this method too early in the construction phase can lead to incorrect forecasts if the soil has not yet settled or been compacted by heavy rollers.
