Our experience with photogrammetric surveying begins in 1999 with the project “Excavation of the Neolithic settlement Kantou-Koufovounou in Cyprus” using traditional photogrammetric techniques. We continuously evolve following the technological advances and moving from analog to digital photogrammetry.
Aerial mapping with unmanned aerial vehicles is a method that developed rapidly in the 2010s because of:
- Camera sensors with high resolution.
- The evolution of computer capability.
- The increase of disk storage space.
- The ability to program an autonomous flight using UAVs.
The above advances made this method affordable and appropriate for a wide range of applications, such as mapping archaeological sites, quarries, buildings, coastal lines, residential areas, hazardous or inaccessible areas etc.
ADVANTAGES OF AERIAL MAPPING WITH UAVs
- The ability to choose the time of the shooting, according to the client’s needs.
- Shooting from low altitude (close range aerial photos).
- Low cost and short delivery time in contrast to manned aerial vehicles.
PROCEDURE FOR ORTHOPHOTO GENERATION
The photogrammetric procedure has both field and office work:
- At the field, targets are placed and measured while the best possible flight to obtain the aerial photos is determined according to the area of interest and the need for accuracy.
- Next, the aerial photos are processed with the use of photogrammetric software to create an orthophoto map and a 3D model of the area, both georeferenced to the national reference system GGRS’87. An analytical report of the process is produced.
The aerial photos are combined to produce an orthophoto map
- Point cloud: points with three-dimensional coordinates.
- Orthophoto map: an image of the entire area, which can be used to measure true dimensions and enriched with grid, contours, the coastal line etc.
- Digital elevation model: a 3D depiction of the area, which can be given in many forms, such as contours, triangulated irregular network or coloured terrain maps.