01 / Positioning
RTK/PPK dual-frequency GNSS
Survey-grade accuracy requires dual-frequency (L1/L2 or L1/L5) GNSS receivers with RTK real-time correction or PPK post-processing. RTK provides live centimeter-level positioning for precision grid execution; PPK eliminates the need for a continuous base-station link and corrects position data after the flight. A well-integrated GNSS module with a survey-grade antenna and low noise figure ensures consistent fix quality even near tree lines and terrain features.
02 / Sensor
High-resolution camera with global shutter
A mechanical or global electronic shutter eliminates rolling-shutter distortion that degrades photogrammetric reconstruction. Minimum 24MP full-frame or APS-C sensor with a fixed prime lens (24-35mm equivalent) provides the optical consistency required for structure-from-motion processing. The lens should be mechanically fixed at infinity focus with a calibrated distortion profile loaded into the processing workflow for sub-pixel accuracy.
03 / Endurance
Flight-time optimization for coverage
A fixed-wing platform covering 400 hectares at 17 m/s completes the grid in roughly 35-40 minutes of cruise flight. Multi-rotor platforms trade speed for hover flexibility and are better suited to smaller sites, corridor mapping and urban 3D modeling where oblique imagery is required. Battery capacity, airframe drag and propeller efficiency together determine whether the survey completes in one flight or requires multiple battery swaps that introduce logistical friction.
04 / Autonomy
Mission planning flight controller
A flight controller running ArduPilot or PX4 with survey-grid mission planning (Mission Planner or QGroundControl) automates the entire acquisition: takeoff, transit to survey block, cross-track grid execution with specified overlap (75% forward, 65% side typical), terrain following via SRTM or onboard rangefinder, and autonomous landing. The FC must trigger the camera at precise distance intervals rather than timed intervals to maintain consistent overlap regardless of groundspeed variation.