Metashape + GNSS/RTK Workflows for Surveying: How Accurate Is It?
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Metashape + GNSS/RTK Workflows for Surveying: How Accurate Is It?

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Agisoft Metashape is one of the most powerful photogrammetry tools used in surveying, and when paired with GNSS and RTK workflows, it becomes a precision-grade solution. This article explains how GNSS and RTK work with Metashape, what accuracy you can realistically expect, and how to set up a reliable workflow for land surveying in 2025.

Understanding GNSS and RTK in Surveying

GNSS (Global Navigation Satellite System) is a general term covering GPS, Galileo, GLONASS, and BeiDou. RTK (Real-Time Kinematic) enhances GNSS accuracy by using real-time correction signals from a base station or network (NTRIP), enabling centimeter-level positioning. Many modern drones like the DJI Phantom 4 RTK and Mavic 3 Enterprise support RTK integration directly.

RTK Drones + Metashape: How It Works

  • The drone collects photos with embedded GPS + RTK metadata
  • Metashape reads the geolocation tags during photo import
  • Metashape can use this data to estimate camera positions
  • GCPs (Ground Control Points) can be added for accuracy validation and adjustment

Accuracy Levels You Can Expect

The achievable accuracy depends on whether you use:

  • RTK only: 2–5 cm horizontal / 5–10 cm vertical (good for general mapping)
  • RTK + GCPs: <2 cm absolute accuracy (suitable for cadastral or engineering work)
  • No RTK or GCPs: 1–2 meters accuracy (not recommended for surveying)

Setting Up a Survey Workflow

To get reliable results, follow these steps in your RTK Metashape project:

  • Step 1: Plan a drone mission with 80% frontal / 70% side overlap
  • Step 2: Connect the drone to an NTRIP network or base station
  • Step 3: Use consistent flight height (60–120m) and manual camera settings
  • Step 4: Place a few GCPs for control or QA (if desired)

Importing and Processing in Metashape

  • Add Photos: Load all images with embedded RTK tags
  • Check Accuracy: Go to Reference tab and view coordinates & precision
  • Align Photos: Use “High” accuracy, preselection “Reference”
  • Place GCPs: Optional, but boosts accuracy when added
  • Optimize Cameras: After placing GCPs, run optimization for better geometry

GNSS Data Formats and Compatibility

Metashape supports EXIF GPS tags, CSV files with external geotags, and log files from GNSS receivers. For best results, match the coordinate reference system (CRS) used during flight with your Metashape project (e.g., WGS84 or UTM zone).

Using PPK Instead of RTK

If real-time RTK correction isn’t available, PPK (Post-Processed Kinematic) is a viable alternative. PPK workflows use raw GNSS logs and correction data from a base station after the flight. Once processed (e.g., in Emlid Studio or RedToolBox), precise positions are written into a CSV and imported into Metashape for geotagging.

Use Case: Surveying a Construction Site

A surveying company in Germany used a DJI Matrice 300 RTK with Zenmuse P1 to capture a 25-hectare construction site. They used NTRIP corrections and a few GCPs to ensure sub-2 cm absolute accuracy. The data was processed in Metashape and exported as a point cloud and orthophoto, which were later used in AutoCAD Civil 3D and QGIS for further analysis and documentation.

Final Tips for Survey-Grade Accuracy

  • Use RTK or PPK correction methods—avoid standard GPS only
  • Check geotag precision in the Metashape Reference panel
  • Place GCPs in difficult terrain areas or near vertical structures
  • Calibrate the drone camera for better internal parameter estimation

Conclusion

Agisoft Metashape combined with RTK or PPK GNSS workflows delivers excellent accuracy for surveying applications. Whether you’re working on topographic maps, land registry updates, or construction layouts, a well-calibrated drone and a consistent photogrammetry process will provide survey-grade deliverables with confidence. In 2025, this integration is more accessible than ever.