Photogrammetry is one of the fields of science and engineering, consisting in the reproduction of shapes, sizes and relative positions of real objects and presenting them in a digital form using photograms, i.e. photogrammetric photos.
Depending on the method of picture taking, we can distinguish two types of photogrammetry:
- Ground and
- Aerial.
The use of both of these methods, limited in the past by the need of expensive and heavy equipment such as analog cameras and aircrafts, is currently flourishing. Thanks to the use of technically advanced drones equipped with appropriate positioning system as well as light and very precise digital cameras, the profitability of this method increases at an exponential rate.
The ability to capture accurate image data combined with smooth recording of position parameters and fast processing in advanced programs turns out to be an extremely effective method for transferring the reality to the virtual world.
This applies to large areas or objects as well as all types of buildings or other engineering structures and to small objects, which shape can be described in an extremely precise digital form, including even such details as the object colors.
Other advantages of this method are as follows:
- Speed of data acquisition in the form of a point cloud.
- Simultaneous photographic registration of details of the scanned object in the form of photos, which also constitute a documentary value.
- Limitation, shortening and automation of field works (when used in geodesy and construction industry).
- Ability to measure and inventory hard to reach elements.
In our work we use the Phantom 4 RTK drone. In addition to the technically advanced imaging system in the form of a 1-inch, 20-megapixel CMOS matrix, this drone is equipped with an RTK module that allows real-time position corrections obtained from commonly used satellite navigation systems. This combination has significantly optimized photogrammetric effects, allowing data acquisition with centimeter accuracy.
Which analysis do we carry out based on the point cloud?
- Site classification, filtration of e.g. vegetation.
- Division into layers, e.g. vegetation, heaps, embankments, excavations, roads, buildings, etc.
- Surface and volume calculations, e.g. roof surface , object height
- Construction site layout.
- Distance measurement.
- Volume measurement, e.g. excavation volume (to know how much weight is left to be removed).
- Construction inventory.
- DSM digital surface model.
- DTM digital terrain model .
- Map for design purposes.
- Contour map generated on the basis of DSM, DTM.
- 3D models with photorealistic textures.
- NDVI or GNDVI vegetation index maps.
- Soil moisture maps.
- Maps of nutrient deficiency in the plant cover.
- Maps of damage caused by pests.
In the case of laser scanning, photogrammetry, obtain the point cloud analysis, write to us! 😉