For a long time the main form of surveying involved starting from known points, measuring the angles between them to determine the position of the instrument. This is the method used in theodolites and total stations. Then in the 80s the first commercial GPS instruments started entering the scene - indroducing a brand new mode of surveying. Since then many new modes of surverying have been introduced, as well as combinations of existing ones. Aerial Lidar systems mounted on commercial airplanes or spacecraft have made it possible to scan huge areas with high relative accuracy, fixed position 3D scanners have made it possible to capture complex scenes quickly, capturing millions of points from each station.
 |
| A point cloud in Pix4D |
For the past 10 years even more new modes of surverying have been added to the suite of tools available to surveyors. These tools are becoming increasingly less expensive and easier to use - to a degree that some have tried to rebrand the field as reality capture. Due to the falling price of technology, more and more consumer grade products have been appearing. An example of this is 123D Catch, which uses photogrammetry to capture 3D geometry through a smartphone. The flood of affordable drones has also left its mark with pro-sumer products such as Agisoft Photoscan or Pix4D that make mapping and the generation of 3D point clouds possible for consumers. This is an area that has been exclusive to surveyors and people with access to aircraft and expensive sensors.
For some years now, depth camera sensors such as the Kinect, have been available to consumers. These sensors combine a normal camera with a depth sensor which allows for creating a living point cloud. While the kinect was initially meant as an input method for controlling video games, many have shown that this can also be used for mapping. This is made possible by SLAM (Simultaneous-localization and mapping). SLAM allows for both building a point cloud of the sensors surroundings, but also keeps track of the sensors position and orientation. This technology is currently under rapid development as this is a key ingredient for making it possible for automated cars and robots to understand their environment. Recently a smartphone with a depth camera has been released by Lenovo and Google. SLAM is also being used with other modes of data collection such as lidar for rapid mapping of large buildings. Here an example from danish engineering consultants Cowi.
Even more recently, methods for doing the same with regular cameras, have been invented. The video below shows how a point cloud is built using nothing but input from a camera. The point cloud is built in real time.
The amount of data most certainly has gone exponential in surveying. We have gone from sparse measurements, collected one by one by a surveyor to tens of thousands of points being collected each second. The price of equipment is falling. Just recently researchers have developed a Lidar sensor on a chip that they state will be available to consumers within a few years for as low as $10. These sensors currently lie in the range of hundreds or thousands of dollars.
 |
| A Lidar chip |
As the devices used for surveying or reality capture fall in price it is safe to assume that more and more people will gain access to them. Many of the tasks that are currently in the domain of surveyors will fall out of their domain. The amount of field work for data capture will most certainly be reduced for surveyors and the amount of data processing will increase. In many cases the surveyors will process data captured by others. Similarily the amount of setting out will also be reduced as the industry moves towards machine guidance and control systems.
One thing is certain, there will be no status quo.
No comments:
Post a Comment