TITLE: UAV - RGB orthomosaic from Laevasvagge, north-western Sweden.
SITES STATION: Tarfala Research Station
TIMESTAMP: 2019-09-07 11:15 - 2019-09-07 11:30
TIME ZONE: UTC +1
SAMPLING POINT: Centroid of location polygon - UAV Laevasvagge until 2020  
LATITUDE: 68.042876
LONGITUDE: 18.960834
ALTITUDE: 956.9 m a.s.l.

FILE RETRIVED FROM: https://data.fieldsites.se
DATA POLICY: SITES data is licensed under a Creative Commons Attribution 4.0 international license (http://creativecommons.org/licenses/by/4.0/).

PARAMETERS & UNITS: DN (-), H (m), V (m s-1), WS (m s-1)

DESCRIPTION: 
Near-ground RGB orthomosaic generated from a UAV platform, with a RGB camera. Nominal pixel resolution is 5 cm. 
The ecosystem surveyed is a mosaic of Natural grassland (CORINE: 3.2.1) and Heathland (CORINE: 3.2.2) determined by the micro climate of a hummocky terrain in an arctic alpine valley.
The UAV flight covers an area which is defined by the following polygon coordinates (latitude, longitude in GCS WGS84, decimal degrees): 
68.045321, 18.954898; 68.045192, 18.967574; 68.040314, 18.966735; 68.040711, 18.953901; 68.045321 18.954898

FLIGHT PARAMETERS:
75% side and front overlap, nominally. 
Nominal flight height (H) 100 m above ground surface.
Nominal flight speed (V) 8 m s-1.

WEATHER CONDITIONS:
Light conditions during the flight were mainly sunny.
Average wind speed (WS) during flight was between 0 - 2 m s-1.
 
SENSOR DESCRIPTION:
Data acquired with a HERO4 GoPro camera. 

GEOREFERENCING: 
Geometric correction performed with 8 Ground Control Points (geometric model RMSE: 0.038 m)
The orthomosaic projection is SWEREF99_TM (EPSG:3006).

PROCESSING METHODS:
Orthomosaic processed using Metashape 1.6.2. 
Details about processing can be found in the Metashape report (SITES_UAV-RGB_TRS_LAE_20190907.PDF) which is available
within the downloaded .zip folder.

QUALITY CONTROL FLAGGING (QFLAG):
Quality flag value for the RGB flight is 132. First and second digit refers to the radiometric and geometric accuracy respectively while last one remaining 
refers to the presence or absence of visual artificats in the data if any. 
For detailed information about data quality flagging system used within SITES Spectral, refer to this document (SITES Spectral – Data Quality Flagging (QFLAG) Documentation; PID: https://meta.fieldsites.se/objects/yHjlJ9dsmPzMNAGPswfSlEtC)

PERMISSIONS:
This material has been inspected and approved for dissemination by Lantmäteriet.




