Mapping spatial spread with a reasonable accuracy is still a challenge in areas which are not easily accessible and at times dangerous, like wetlands, mines or forests. Traditional surveying techniques like GPS or optical surveying instruments, consume a lot of time and manpower as the surveyor needs to physically reach the point for which the data has to be collected. Hi-Res cameras, storage facilities & improved computing technology have enabled drones to collect, process and interpret high-resolution imagery easily. Drones used for photogrammetry take sideways, forward and zone overlapped series of pictures, which are ortho-mosaicked using techniques like image matching and geo-referencing with the help of differential GPS.
The increasing miniaturization of sensors like GPS, Gyro, Compass, barometer, proximity, accelerometers etc. has turned drones into powerful machines. With time, the accuracy of stand-alone sensors will increase and will help in reducing the computing for mosaicking and creating ortho-images. This unique combination of sensors and software will allow humans to map the area quickly for various challenging engineering and planning applications. Computer-aided image analysis using machine and deep learning techniques like object-based classification, neural networks, pattern recognition etc. are helping us in driving knowledge from the images. Typically, sensors mounted on a drone produce high-resolution images, which can reach even up to 1 cm or better, enabling visualization or object recognition on the ground easily, but the size of images in terms of storage and extent is large which makes it difficult and time-consuming for a user to manually analyze them at times. Image analysis programs prove to be very handy in such a situation.
Like every other technology in the surveying industry, drones have also seen a dramatic buzz. It is common to misinterpret a drone as a one-stop solution for all survey and mapping needs. Basics of Land Surveying and the use of accurate ground control points using dual frequency GNSS receivers do play a major role in making drone-generated outputs. In almost all of our infrastructure survey and mapping projects, we have found that a well triangulated Ground Control Network adds immense value to the drone outputs, like orthomosaics and aerial point clouds.
The recently released drone policy by DGCA brings in much-needed legitimacy to the industry and will certainly help several drone manufacturers in India to explore applications and develop products for engineering requirements. This small step of the government will pave way to a giant leap in innovation in image capturing and software development in India. The policy opens doors for using drones in application areas like slum mapping, estimating earth work for road construction, planning of micro irrigation projects, assessing crop health, developing better inland waterways, planning of urban areas, monitoring mines and excavation, monitoring solar plants and finding solar potential of roofs, construction monitoring etc. More accurate 3D data will certainly help in better cost estimation and timely completion of projects.
Countries like India, where development of infrastructure to sustain more than 1.3 billion of population is a major challenge, look to such modern technologies for rapid surveying and mapping. In addition to infrastructure projects like smart cities, land reforms, expressways and highways, social projects like slum rehabilitation etc. stand benefited as well.
We at Transerve adopted drone technology early on and continuously work at exploiting photogrammetry to create geospatial database and survey drawings for infrastructure development. We explore more areas where drones can transform project execution and help clients monitor and protect their investments.
Authored by Amarsh Chaturvedi and originally published on E-gov Elets Magazine. Write to us at firstname.lastname@example.org to know more about how our innovative geospatial solutions augmented with drones have solved tough problems.