The Challenge
Topographical surveying and Mapping of the study area were performed using a UAV and Visual Payload mounted underneath. This solution will allow Customers to recreate an accurate Orthophoto, DSM, and DTM, enabling customer engineers to identify potential problems, accurate planning, and measurable data.
GIS Drones are required to perform data acquisition and Mapping through an aerial topographical survey using PPK-enabled drone technology. Aerial surveys of given study areas detailed below in the proposed solution will be conducted using autonomous UAVs capable of capturing PPK corrected georeferenced imagery and deliverables from data processing.
The study area will be surveyed, and the data will be captured with the highest quality possible while meeting the required parameters.
GIS Drones responsibility will be to plan the flights and acquire aerial data that is PPK corrected. After data capturing, GIS Drones will perform the data processing part using a High-end processing system with licensed Mapping software.
The Proposed Solution
The dedicated GIS Drones teams will be deployed for Aerial Topographical mapping and will be responsible for capturing and processing required deliverables.
Each team will be equipped with suitable UAVs, payloads, and tools to facilitate their missions.
Phantom 4 RTK with Mobile station
GIS Drones Operation team using Phantom 4 RTK system with the mobile station to do aerial capturing of raw imageries at respected sites.
DJI RTK-2
Software
GIS Drones has the dedicated Mapping Photogrammetry in-house software to do multiples analysis, storing, manipulating, Mapping, etc., for the geospatial data sets.
The software can process several types of data processing including:
Deliverable Considerations:
Deliverable Considerations:
We conducted the entire survey and concluded the following results:
| Total number of photos | 4520 |
| Total data size (MB/GB) | 227 GB |
| Parameters used in Processing | Photogrammetric Aerial Triangulation, IDW method |
| Time consumed for Ortho mosaic | 20 |
| Time consumed for DSM construction | 18 |
| Time consumed for DTM construction | 16 |
| GSD of the original photo | 2 cm |
| GSD of results | 3 cm |
The table below shows general data settings and accuracy outputs based on the requirements provided by the client.
| GSD (Ground Sampling Distance) | 2.5 cm |
| Flight Altitude | 100 m |
| Lateral Overlap | 75% |
| Longitudinal Overlap | 80% |
| X, Y Accuracy expected | 3 – 5cm |
| Z Accuracy expected | 3 – 5cm |
ORTHOPHOTO
DTM
DSM
Deliverable Considerations:
The alternative was to conduct a manual survey, which would’ve taken weeks, and the data wouldn’t have been accurate.
Not to mention the manpower required for such a huge survey. The cost of operation, the post-processing time, and the data output limitations.
With Drones, we avoided all of that.
We were able to provide the following benefits to our clients:
Conclusion
UAV-based Topographical surveying and Mapping provide more precise results than traditional surveys with less cost, time, and Manpower.
Drones can be deployed during Pre-construction, Ongoing construction, Construction progress monitoring, and post-construction.
Drones in Aerial surveying and Mapping are useful decision-making information for the people working on the project as Architectures, planning engineers, site and construction managers, Stakeholders, and building masterplan for city or commercial constructions.