GRADISS have dedicated team for survey and mapping activities. The main purpose of surveying is to decide the three-dimensional relationships between different locations. Knowing information like the distances and angles between points and lines helps engineers determine how to draw up plans for public buildings, homes, roads, bridges and a variety of other construction and infrastructure projects.
Technologies:
- Computer-assisted drawing (CAD): Once engineers have gathered survey data, computer-assisted drawing helps turn that data into a useful visual representation, such as a map or three-dimensional model. CAD allows for a greater level of precision and detail than could not be achieved with manual sketching or drawing.
- Global positioning satellite data: GPS data is crucial for civil surveying because it allows for the pinpointing of precise locations and coordinates. Where a visual assessment alone would be insufficient for determining whether a corner had shifted or a foundation had sunk, the pinpoint accuracy of GPS data allows engineers to know for sure.
- Aerial photogrammetry: Drones are often useful for the aerial photography necessary in civil engineering. Once they have a number of aerial photographs of the landscape or site in question, engineers can use aerial photogrammetry to extract topographical data from the photos. Aerial photogrammetry combines multiple shots from different angles to create an accurate 3D model.
- Point cloud modeling: To develop accurate 3D survey models, engineers also often create a point cloud or a set of three-dimensional data points. Surveyors use 3D laser-scanning technology to generate a data map of the area they wish to model. Once they have data that represents every surface they need, they can then bring the points together through point cloud modeling into an accurate and detailed 3D model.
Types:
- Construction surveying: Construction surveying is useful for evaluating the arrangement of the buildings, roads, power lines, gas mains and other structures surrounding potential construction sites. Analyzing this information makes it easier to plan construction projects.
- Deformation surveying: Deformation surveying supports to found if a geographical or man-made feature, such as a road, foundation, coastline or river, is changing shape. In deformation surveying, engineers record the three-dimensional coordinates of specific points. After some time has elapsed, they record the coordinates again to see if they have changed. A comparison of the two data sets can disclose if deformation or movement has occurred.
- Geological surveying: Geological surveying maps out features of the physical landscape, such as rivers, valleys, mountains and more. Satellite data is essential for geological surveying, and engineers frequently use satellite data or aerial photographs to help them in their work.
- Hydrographic surveying: Hydrographic surveying is similar to geological surveying, but it maps out coastlines specifically. Accurate hydrographic surveying is crucial to the work of the Coast Guard and any marine rescue operations. It also helps create navigational maps for sailors and assists conservationists in managing coastal resources.
- Topographic surveying: Topographic surveying analyzes the shape and physical features of a particular landscape. Engineers assess the height of different geographical coordinates and then draw contour lines to indicate areas of the same elevation. They can then use these findings to create topographical maps and to assess terrain for future building or infrastructure projects.
Applications:
- Generating topographical or marine navigational maps.
- Preparing plots.
- Preparation for new construction projects.
- Estimating projected paths of roads, railways, power lines and irrigation systems.
- Assessing and recording the boundaries of different properties to determine land ownership.
- Analyzing topography.
- Assessing the position of existing structures like highways, canals, dams and bridges.
- Planning and constructing mines.
- Preparing for military operations and engagements.
- Charting navigational routes.