Essential Aspects to Consider When Comparing Terrain Data Collection Methods
The relationship between construction contractors and surveyors has stood the test of time for the simple reason that building and construction projects cannot be implemented without terrain data. Landscape data collection has been made possible through technological advancements that have given rise to digital terrain modelling.
In collecting the data, surveyors employ different methods with the well-known techniques being ground surveys, aerial photogrammetric data capture, cartographic surveys, airborne laser scanning and satellite imagery. Therefore, when hiring a surveyor to provide you with terrain data, it is essential to analyse each technique before settling on one.
This article highlights different aspects that you should look at when comparing data collection methods for digital terrain model surveys.
Cost -- Some terrain data collection techniques are more expensive than others. First, elevation data collection techniques that involve the use of the latest technologies cost less compared to traditional ground surveys. The reason is that a lot of effort and resources go into the process of preparing elevation data through manual groundwork. Several groundsmen with stereoplotters have to be positioned in different locations for data collection. However, the same cannot be said when using the latest technology since a limited workforce is required. Additionally, data analysis takes a short time when utilising technology for analysis and graphing. For this reason, for example, aerial laser scanning and satellite imagery techniques are less expensive compared to ground surveys.
Accuracy -- Compromising on accuracy in terrain data collection is not an option since the integrity of a structure largely depends on the information. The same way digital terrain modelling methods vary in cost is the same way they differ in accuracy. For the most accurate data, surveyors prefer laser scanning due to its advanced error resolution features and the ability to detect underground structures. For instance, laser scanning helps engineers to map underground electric lines as well as sewerage systems among other utilities. The second most accurate method is ground surveying because surveyors record what they see physically which eliminating guesswork.
Sampling Density -- While it is possible to achieve the required sampling density through ground surveys, it would take a long time to complete collection of enough data for the sample. It is why surveyors prefer to employ satellite imagery rather than ground surveys for their sampling density. Satellite imaging covers a large area at a time compared to other techniques. However, it is important to mention that the resolution of images obtained from satellite imagery needs to be as close as possible to ground level resolution for accurate results.
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