Exploring the Potentials of UAV Based Geo-Spatial Data Acquisition in Urban Environment: A Case study in Dhaka City, Bangladesh

The usage of Unmanned Arial Vehicle (UAV) is undoubtedly very potential as well as very rapidly growing geospatial data acquisition method with disruptive role in the domain. The main focus of this research is to utilize an indigenous Quad-Copter to acquire spatial data in complex urban environment with a view to
illustrating the potential using UAV data in urban planning and management activities including utility services. The study was conducted in a dense area of Dhaka city, the capital of Bangladesh. The process started with using an indigenous quad-copter; in this case, Mission-planner has been utilized to prepare a flight path for the UAV. After conducting the flight, extensive image processing has been operated, through synchronization of images, registration of the images, bundle block adjustment. For image processing and further extraction of data, Pix4DMapper and Correlator3D have been utilized. Moving forward, the processed images are used to prepare DTM, DSM, Orthographic images, and 3D point clouds. The process provided the data that are essential for several urban planning operations; such as Land Use planning, extracting urban volumetric data, extraction of vegetation structure, and common uses of DTM and DSM. The unique features of the UAV data for Dhaka is highly accurate, as Dhaka is mostly built us unplanned city, the urban fabric is very complex to extract data from medium or semi-high resolution optical satellite images. The UAV data used in this case study has provided 5cm resolution for orthophoto, planimetric accuracy of 2 cm and height accuracy of 5 cm. This study
seems to be very effective with special regards to time and cost saving with a significant improvement in data quality. This effort also helps us to overcome the limitations of cloud cover, spatial and temporal resolution of optical satellite images.