Uncrewed Aircraft Systems (UAS) Multispectral Orthomosaic - Cockatoo Hills, Tasmania 

This dataset contains UAV multispectral imagery collected as part of a field trial to test the Uncrewed Aerial System to be used for the TERN Drone project. The UAS platform is DJI Matrice 300 RTK with 2 sensors: Zenmuse P1 (35 mm) RGB mapping camera and Micasense RedEdge-MX Dual (10-band multispectral sensor). P1 imagery were geo-referenced using the onboard GNSS in M300 and the D-RTK 2 Mobile Station. P1 Camera positions were post-processed using AUSPOS. Flight conducted between 10:26 am and 10:47 am AEDT at flying height 80 m, forward and side overlaps for Zenmuse P1 set to 80%. MicaSense RedEdge-MX Dual triggered using timer mode (every second).

Micasense multispectral sensor positions were interpolated using P1, following which a standard workflow was followed in Agisoft Metashape to generate this orthomosaic (resolution 5 cm). Reflectance calibration was performed using captures of the MicaSense Calibration Panel taken before the flight. The orthomosaic raster has the relative reflectance (no unit) for the 10 bands (Coastal Blue, Blue, Green 531, Green, Red 650, Red, RedEdge 705, RedEdge, RedEdge 740, NIR). The cloud optimised (COG) GeoTIFF was created using rio command line interface. The coordinate reference system of the COG is EPSG 7855 - GDA2020 MGA Zone 55.

In the raw data RedEdge-MX image file suffixes correspond to bands like so - 1: Blue, 2: Green, 3: Red, 4: NIR, 5: Red Edge, 6: Coastal Blue, 7: Green 531, 8: Red 650, 9: RedEdge 705, 10: RedEdge 740. However, in the processed Orthomoasic GeoTIFF, the bands 1-10 are ordered as per the Central Wavelength (Coastal Blue, Blue, Green 531, Green, Red 650, Red, RedEdge 705, RedEdge, RedEdge 740, NIR). 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging. This work was funded by the Terrestrial Ecosystem Research Network (TERN), an Australian Government National Collaborative Research Infrastructure Strategy (NCRIS) project. Data was collected and processed by the Department of Geography, Planning and Spatial Sciences at the University of Tasmania. 

The main purpose of collecting this data was to test and establish data processing protocols for the M300 RTK system. The onboard GNSS system enables direct georeferencing, and potentially removes the need for ground control points. The purpose of generating this orthomosaic data product was to test the data upload capacity with TERN Data Services team. 

Raw data was collected using the Zenmuse P1 RGB mapping camera in a DJI M300 RTK UAS platform. D-RTK coordinates collected in the field were post-processed using AUSPOS. The updated coordinate was used to shift the camera positions of the P1 camera and interpolate those of Micasense prior to processing the imagery in Agisoft Metashape.

A multispectral orthomosaic with relative reflectance in the 10 bands of resolution 5 cm was generated and rio command line interface used to create this Cloud optimised GeoTIFF.