Drone Photogrammetry

Posted on 1st Feb 2019

by Admin

drone photogrammetry

Drone Photogrammetry is increasing rapidly.  Aerial surveying using drone is very cost effective as compare to hiring an aircraft using photogrammetry equipment. With the collaboration of drone with GPS, digital cameras and powerful computers system, the survey job become more efficient. The output from photogrammetry is typically a map, a drawing or a 3D model of some genuine object or terrain.

Drone photogrammetry refers to the process of taking photos from aircraft, satellites and other aircraft in the air, and combining the ground control point measurement, mapping and stereo mapping to draw the topographic map.

At the time of photography, the aircraft was photographed in a parallel flight along the designed route to obtain aeronautical photographs with a certain degree of overlap. Using the principle of photogrammetry and the principle of stereo mapping, the photo will be composed into a three-dimensional model to engage in various map mapping and feature interpretation. Aerial photogrammetry is to measure the fifth spatial relationship, such as coordinates, elevation, distance, etc., and finally to obtain topographic maps, plan views, image maps and three-dimensional ground models. Its graphics speed is fast, high precision and uniform, which is an important development direction of digital mapping in the future. Aerial photogrammetry provides basic urban spatial data for digital city construction, and is widely used in land and resources surveys, land use, urban planning, road traffic, port location and real estate. According to the vertical axis of the main optical axis of the camera objective lens, it can be divided into orthophoto aerial photography and oblique aerial photography.

Based on aerial photogrammetric spatial data and basic geospatial data, four main products are generated: digital line drawing (DLG), digital orthophoto (DOM), digital elevation model (DEM) and 3D model.

The basic content of vector data that can be made and the scope of coverage are: geodetic control measurement data (including plane control points, elevation control points, gravity points), water systems and ancillary facilities, buildings and ancillary facilities, transportation and pipeline facilities, realms, Surface coverage and landforms.

There are two type of photogrammetry either in oblique photography of using LiDAR (Light Detection and Ranging). Oblique photography is to overlap photos of an object or land with the use of UAV accommodate with waypoint navigation technology.  Drone LiDAR comprises 3D laser scanner which mounted on the drone to do the measurement of the height of points in the landscape. The accuracy of the measurements allows the 3D models to be used in planning, design, decision making process across many industries. Besides, LiDAR sensor also can pierce dense canopy and vegetation, can capture bare earth structure which satellites cannot see.

Drone Photogrammetry – aerial imagery:

1.       DEM (Digital Elevation Models) / DTM (Digital Terrain Models) / DSM (Digital Surface Models)

2.       DOM (Digital Orthophoto Map)

3.       3D architectural Modelling

4.       Volumetric / Quantity Survey

5.       Plane metric features (road edges, building footprints, heights, signs etc)

 

LiDAR is still an expensive technology, and consequently, it may not be the best choice for every project. Though LiDAR is a more advanced technology, it’s also a specialized tool: its primary benefit is its ability to penetrate to the ground and to produce clean, readable, and accurate 3D files. For many surveying applications, photogrammetry may still be a suitable choice — with the understanding that it isn’t as likely to be precise or accurate as LiDAR. It all depends on the type of surveying that has to be done, as well as the budget.



To find more about MIRS Innovate -Drone Photogrammetry, please contact us at +65 62450136.