The surveyor has the ability to create a digital terrain model (DTM) from collected data. In essence this is a spatially correct computerised representation of a site. As such, things can be added, overlaid or manipulated and dimensional information can be directly queried. The DTM is thus the starting block for any subsequent design project and can form the base information for many land and industrial GIS applications.
By generating surfaces within the DTM volumetric information can be obtained. Questions concerning quantities such as cut & fill can be answered quickly and accurately. Laborious calculations, traditionally done by hand, can be performed many times at high speeds. This enables the designer to try out more options, giving greater flexibility and ultimately a more cost-effective solution.
Design elements can be added to a model. For instance road alignments can be manipulated both horizontally and vertically to make best use of topography. Structures and drainage information can be incorporated, showing how they fit together and interact with each other in true 3-Dimensional space.
A further benefit obtainable from the DTM is the abifslity to visualise a future scheme. Design information, in combination with computer graphics and digital photography, can be 'draped' over a model to form a realistic virtual project. It is possible for prospective clients and planners to enter into the model in real time, experiencing the views they would do with the real thing.
We use the software package n4ce from Applications in Cadd for completing much of our digital modelling work. It has been adopted by several government agencies and teaching departments, and is extensively used in the construction/survey industry throughout the UK and Europe. n4ce supports transfers into most major design software used throughout the industry.
We have been involved in many projects requiring alignment design and volumetric calculations. These have ranged from major works at international airports in the UK and abroad, dealing with hundreds of millions of cubic metres of material, down to simple cut & fill road designs. We have extensive experience in volume calculations for land fill sites and mining/mineral extraction. In every case we liaise closely with the client and our flexible approach ensures that specific requirements are fulfilled.