Unmanned Aerial Photogrammetric Survey is the use of Unmanned Aerial Vehicles (UAVs) or Drones to take photos for use in photogrammetry, the science of making measurements from photographs. Instruments manufactured for UAVs could be mounted on unmanned flying platforms of various sizes and types, such as octocopters. These machines are suitable for the full geodetic survey of a study site by creating a point cloud of measurements of nearly homogenous quality and accuracy. These detailed point clouds (of various types of data) could be used in line with orthophotos etc. to obtain a complex data system representing the study site. UAVs are suitable to acquire three-dimensional digital models and orthophoto mosaics for a certain area.
Advantages of Unmanned Aerial Vehicle (UAV) / Drone Survey
- The UAV / Drone Survey machinery can be transported to the site by car; thus, transportation costs and mobilization time are low.
- The deployment of the UAV / Drone Survey machinery is flexible.
- It can operate and produce measurements in cloudy conditions.
- The maintenance, storage and running costs of unmanned platforms are cheaper than the same expenses of conventional aircraft.
- The smaller high-quality unmanned platforms (UAV / Drone) are more efficient, productive and more durable than the conventional unmanned aircraft which could amortize quickly.
- The possibility of drone remote sensing also eliminates any danger that crews of a manned aircraft may be subjected to in difficult terrain or remote areas.
- Drones are now being used with laser scanners, as well as other remote sensors and digital cameras, as a more economical method to scan smaller areas.
- Can be effectively used for 3D mapping of small cities and villages.
Topographic Surveys are used to identify and map the contours of the ground and existing features on the surface of the earth or slightly above or below the earth's surface viz. buildings, roads, walkways, manholes, utility poles, retaining walls, trees, etc. A topographic survey is usually performed by professional Land Surveyors with the goal of producing two-dimensional maps which represent three-dimensional components of the landscape. The purpose of a Topographic Survey is to collect survey data about the natural as well as man-made features of the land, and its elevations. The survey shows the relative positions and elevations of both natural and man-made features on a property.
Topographical surveys are also referred as contour surveys and they are always conducted before there is any change in the ownership of the land or even when the property owner is willing to make some changes in the land. The main focus of the topographical surveys is to provide you with the exact figures of the size, height, position of the different changes that have occurred in course of time with regard to their presence of their natural existence.
Every site is different and presents specific risks and challenges. We at “Prashant Advanced Survey LLP”, have shifted from the primitive method of DGPS & ETS (Electronic Total Stations) to the modern innovative method of DGPS, mobile LiDAR and UAV / Drone for medium to huge and complex sites.
We have procured a DGCA type approved Survey Grade PPK UAV / Drone ‘Lookout VTOL’ from TAS, Bangalore, in 2018, with onboard PPK NovAtel GNSS for data capture and ‘Pix4D Professional Mapper’ software to produce accuracy upto 10 cm in X, Y, Z coordinates. This technology can be used to supplement the Mobile LiDAR data output in case of urban mapping projects, or highways projects having proposed bypass roads. This is also ideal for carrying out Topographic Survey of any land where speed and accuracy is of priority, with the rates better than the primitive Electronic Total Station (ETS) method of survey.
Sample Ortho Mosaic DSM of a site prepared in Pix4D Mapper Professional
The use of such UAV / Drone is ideal for 3D mapping of the smart cities and Town Planning projects in India. About 1 to 1.5 Sq. Km. area can be easily captured by one PPK Survey grade Drone flying with an altitude of about 80 to 100m above average ground level. The Ground Sampling Distance (GSD) obtained varies from 1.5 cm to 5 cm using the Sony Alpha 6000 camera. Where as the accuracy of 10 cm can be obtained in X, Y, Z coordinates using the onboard PPK NovAtel OEM 7700 GPS / GNSS receiver.
The data processing and further output is done using two licenses of Pix4d Professional Mapper Photogrammetric Software and dedicated higher end workstations available with us. Contours can be generated at required intervals say 0.5 m or 1 m, using this photogrammetric data and drawings are prepared up to the scale of 1:1,000 which is sufficient for planning and development of any infrastructure project.
DGCA Type approved PPK UAV Drone “Lookout VTOL” with onboard NovAtel OEM 7700 GNSS
Survey Grade UAV / Drone Instrument Along With Processing Software Owned By M/S Prashant Surveys, Pune
| Sr. | Name of Equipment | Make / model | Numbers |
|---|---|---|---|
| 1) | (DGCA Approved, UAV / Drone, PPK Survey Grade, NPNT, with Rotary wings) LookOut VTOL Lite™- Model TALV2400_C Mapper Series Industrial Unmanned Aerial System for Aerial Mapping, with onboard PPK / RTK NovAtel OEM7700 GPS / GNSS. Bird Specification : RPA Category : Micro, Quad Copter, NPNT Ground Control Station : TAS GCS™ - Industrial Version Sensor: Calibrated A6000 Sony camera on 2-axis Accuracy : X & Y = 2 cm to 5 cm, |
Throttle Aerospace Systems Pvt. Ltd., Bangalore, India. (Made in India) | 1 |
| 2) | UAV Data Processing Software : Pix4d Professional Mapper Photogrammetric Software, Version 4.3.31 |
Pix4d | 2 |
Technical Data Sheet of onboard PPK NovAtel OEM 7700 GPS / GNSS receiver.
Technical Data Sheet of onboard PPK NovAtel OEM 7700 GPS / GNSS receiver.