An quick read which may answer your basic queries on what are the most commonly used drone data outputs and being used currently.
Orthomosaic is made of two words ortho (meaning perpendicular) and Mosaic (Meaning small pieces joined together to form a big one). Numerous aerial pictures from a drone can help create an Orthomosaic Map from WebODM, an open source drone mapping software. Orthophotos are being used across the world, in the fields of Agriculture, Mining, Construction, Real Estate, Police and Fire Department, Insurance, Disaster Management. From planning and monitoring of projects, to issuance of no objection certificates – drone data has become an integral part of any services firm globally.
An Orthophoto is part of the basemap in a Geographic information system (GIS). It is used like a photograph as a visual reference, and since it has the qualities of a map it is used to generate other important mapping data. Mapping can be used for emergency response planning and modeling, response, as well as recovery. Law enforcement can use it for mapping trends, thereby improving performance, and public health agencies can use it for syndromic surveillance. And because the basemap is shared with other local, state and central government agencies, the GIS systems can be used for other applications as well, such as property management, Census, tax assessment, flood mapping, planning, tree counting and economic development.
Digital Elevation Model (DEM) Elevation simply means height. In simplest terms, it can be referred to as Digital Height Model. Thus, a digital elevation model (DEM) is a representation of terrain’s surface only in terms of its height. DEMs are used for Slope Angle, Slope Aspect, Slope convexity, Slope length, Hill Shading and 3D Display across the Engineering Community.
The Digital Terrain Model (DTM) represents the bare ground surface without any objects like trees and buildings. DTM is generally used to generate contour map. DEM is widely used for Cut-and-Fill Problems involved with road design, Site Planning, Volumetric calculation in building dams and reservoirs, Hydro logical run-off modelling.
A 3D mesh is the most accurate representation of the real-world in every from Unlike the point cloud, which is a discrete set of point, a 3D mesh is continuously similar to the real-world.
It also gives us the freedom of measuring in 3-dimension (3D) and hence enabling us to find out the height difference between two points, volume estimation of a specified region, elevation profile of a section, etc.
In simple words, 3D object representation can be a polygon mesh, which consists of a collection of vertices and polygons that define the shape of an object in 3D.
3D Mesh is widely used by consultants, decision makers as Point clouds have less information to be stored, Point clouds are smaller and easier to render mesh representation, Point Clouds are good for producing scene with complex geometry.
An Imaginary line on the ground surface joining the points of equal elevation is known as Contour. In other words, Contour is a line which the ground surface is intersected by a level surface obtained by joining points of equal elevation. This line on the map represents a contour and is called contour line.
Contours are generated from Digital Terrain Model at interval of 0.5m. It is super imposed along with CAD drawings and Orthmosaic in .dwg file.
Purposes of Contouring are enormous, few being:
- Contour survey is carried out at the starting of any engineering project such as a road, a railway, a canal, a dam, a building etc.
- For preparing contour maps in order to select the most economical or suitable site.
- To locate the alignment of a canal so that it should follow a ridge line.
- To mark the alignment of roads and railways so the quantity of earthwork both in cutting and filling should be minimum.
- For getting information about the ground whether its flat, undulating or mountainous.
- To locate the physical features of the ground such as a pond depression, hill, steep or small slopes.
Analysis of Orthographic Map with Site Plans can help city officials for future planning, revenue collection and regular maintenance.
Aerial Video provides a bird’s eye view of the section. Videos captured in several flights were combined to create a seamless video. Annotations of important structures/features are marked in the video.
Use cases of Aerial Videos
- Identifying Right of Way
- Route Survey Analysis
- Locating the alignment of a canal so that it should follow a ridge line
- To mark the alignment of roads and railways so the quantity of earthwork both in cutting and filling should be minimum
- For getting information about the ground whether its flat, undulating or mountainous
- To locate the physical features of the ground such as a pond depression, hill, steep or small slopes
Lidar (light detection and ranging) is an optical remote-sensing technique that uses laser light to densely sample the surface of the earth, producing highly accurate x,y,z measurements. Lidar, primarily used in airborne laser mapping applications, is emerging as a cost-effective alternative to traditional surveying techniques such as photogrammetry. Lidar produces mass point cloud datasets that can be managed, visualized, analyzed, and shared easily.
Do you wish to see sample data sets or wish to talk more on this, please reach out for a chat anytime.
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