Methodology:

Data collection:

Aerial survey conducted using a RPAS (AgEagle eBee X). The survey consisted of collecting overlapping imagery of the target area, with a forward overlap of 95%. The target altitude during acquisition was 95 m AGL (above ground level). During the aerial surveys a geodetic Trimble GNSS base station receiver collected data.

Post flight processing:

Precise point positioning (PPP) was undertaken using the online Canadian Spatial Reference System PPP tool to generate the position of the base station during the survey and which was then used to process the eBee X's onboard GNSS receiver using post-processed kinematic (PPK) processing to improve the accuracy of the camera centres captured during flight.

Photogrammetry / final outputs:

Structure from motion photogrammetry was used to determine the exterior orientation (x, y, z, omega, phi and kappa (or roll, pitch, yaw)) of the camera during image acquisition using a combination of the onboard GNSS solution and common points within the images. Once the camera centre and orientation for each image was determined, a dense point cloud was extracted of the surface within the target area. The dense point cloud was then transformed into a DSM (in metres), which in turn was used to resample the images onto a map projection, removing camera perspective and terrain distortions, in a process called ortho-rectification and resulted in a single complete mosaic of the imagery.

Data collection:

Data collection equipment:

Unmanned aerial vehicle (UAV):

Manufacturer: AgEagle

Model: eBee X

Sensor: AgEagle SODA 3D

Flight management software: eMotion (version 3.23.0)

GNSS base station:

Manufacturer: Trimble

Receiver model: R9s

Antenna model: Zyphr Model 2

Post-flight processing software:

Canadian Spatial Reference System Precise Point Positioning (CSRS-PPP, Version 3)

eMotion (version 3.23.0)

Photogrammetry software:

Pix4D (version 4.9.0.).

Data quality:

Coordinate reference system for outputs:

Projection: UTM Zone 23S

Horizontal datum: WGS84

Vertical datum: MSL (mean sea level), EGM2008 geoid

Resolution of final outputs:

DSM (2.1 cm)

Orthorectified mosaic (2.1 cm)

Calibration accounted for in processing.