Aerial Surveying Gets Smarter and Smarter
Surveyors and GIS professionals have very high standards when it comes to their tools and their profession. So it’s no wonder that many are turning to drones for their mapping and 3D modeling needs. Drones achieve results that meet surveying accuracy standards and compared to traditional surveying techniques, drastically reduce the time, cost and effort required.
Drone surveying is more complicated than taking a few photographs from above. It requires several crucial steps, from the preparation of ground control points, through mission planning, to the processing of capturing images with the surveying software.
Within drone surveying, one technique that has been successful in 3D modeling is the use of oblique photogrammetry, in which images are captured with several lenses that are mounted together in an array with fixed axis angles. The resulting images reveal details that are sometimes lost when capturing only vertical photographs.
Using this cutting-edge technology, surveyors have the ultimate surveying solution at their fingertips, in terms of accuracy and efficiency. Thanks to the intelligent oblique capture feature, surveyors can now capture and create 3D models of their targets more efficiently than ever before.
Oblique photography has many advantages. While a vertical angle can help to show the location of features such as buildings, streets or open spaces, oblique aerial photos are better at giving a perspective of the appearance of features rising from the ground such as buildings, topography, foliage, etc. in relation to the ground and horizon.
Other advantages are:
- Reveals details that might have been obscured in the vertical view.
- Facilitates accurate elevation determination of features.
- Captures much more relative height data.
- The position and relative height information obtained from each data set can be compared, contrasted and pooled to obtain the relative height information between features in the target area, producing a map of both position and height data, which can be represented as a 3D map of the surveyed area.
However, there are also disadvantages. Due to the number of lenses, the equipment can be very heavy and expensive. A heavier payload means shorter flight times and spent more time changing drone batteries, especially in large-scale surveying missions. On the other hand, if oblique photogrammetry or 3D modeling is attempted with a single camera, many flights are required, which takes significantly more time.
With the continued increase in the use of drones in surveying and construction, there is a constant need to make their use simpler and more inexpensive, in terms of time and cost. Aerial surveying has become smarter and oblique capture is one such innovation.
