Topographic Survey and Drone based Mapping

During my work at Geo3D Modelling, our team conducted a professional field survey at different places in Nepal, where we did topographic survey using DGPS and Drones. The work combined ground surveying with Theodolite, level machine, DGPS; and drone mapping using Autel Evo II V3 drones, providing hands-on experience in field data collection, processing, and reporting.Deliverables included raw drone photos, processed orthophotos and DTMs in Geotiff format, and contour maps in DWG format, providing detailed topographic data for each project.

Work was conducted in three main steps:

1. Site Reconnaissance: Assessed terrain, steepness, and access points to plan safe and efficient surveying.
2. Ground Control Points: Three GCPs were installed using concrete poles with steel markers. RTK GNSS and digital leveling ensured precise coordinates and heights. Each point had a reference card (D-Card) documenting its location.
3. Drone Survey: The drone flew at 60m AGL following a pre-planned flight path. GCP flags were used for georeferencing, ensuring high accuracy.
4. Data Processing: Using PIX4D Mapper, captured imagery was processed into orthophotos, DTMs, and contour maps. Accuracy was verified against GCPs with an RMSE of 0.015m.

Survey Procedures & Processed Data

Drone Image Path Capture

Sample Orthophoto

Sample Contour Map

Digital Surface Model (DSM)

Some Sample images are shown below:

Middle Marsyangdi Hydropower Project, Lamjung

Gandak Hydropower Project, Nawalpur, Nepal

Chandrauta, Kapilbastu, Nepal

Surkhet, Nepal

Team Group Picture (Balkrishna dai, Shyam dai, Me, Ashok dai, Missing: Yogesh dai, Arman dai)

Me posing for drone shot

Drone Survey Sample – Site View 1

Drone Survey Sample – Site View 2