TITLE: UAV - RGB orthomosaic from Nybygget, southern Sweden.
SITES STATION: Asa Research Station
TIMESTAMP: 2018-04-16 12:18:33 - 2018-04-16 12:43:22
TIME ZONE: UTC +1 
LATITUDE: 57.14975 
LONGITUDE: 14.738164
ALTITUDE: 256.4 m.a.s.l. 
FILE RETRIVED FROM: https://data.fieldsites.se Link to metadata landing page is available in separate file in the downloaded zip.
DATA POLICY: SITES data is licensed under a Creative Commons Attribution 4.0 international license (http://creativecommons.org/licenses/by/4.0/).

PARAMETERS & UNITS: Reflectance (unitless)

DESCRIPTION: 
Near-ground RGB orthomosaic generated from an UAV platform, with a RGB camera. Pixel resolution is 2.23 cm. 
The ecosystem surveyed is a coniferous forest composed by Norway spruce (Picea abies). The forest is part of the Asa High Yield Experimental Forest, which addresses questions regarding intensive forest management on a landscape level, such as fertilization and water quality, tree species introduction and their influence on flora and fauna, intended to study the forest growth under different management regimes. The stand at Nybygget was planted in 2006 and it has been fertilized every second year since 2016. 
The survey area is a polygon defined by the coordinates (GCS WGS84, decimal degrees): 57.147334, 14.737392; 57.148636, 14.741848; 57.150945, 14.738692; 57.150012, 14.734504. 

FLIGHT PARAMETERS:
Nominally, 75% side and front overlap. 
Nominal flight height 80 m above ground surface.
Nominal flight speed 8 m/s.
Survey area was flown in two separate UAV flights (U01 and U02). 

WEATHER CONDITIONS:
Light conditions during the flight were complete cloud cover.
Average wind speed during flight was 3 - 5 m/s.
 
SENSOR DESCRIPTION:
Data acquired with a Parrot Sequoia RGB camera, on board of a quadcopter UAV. 

GEOREFERENCING: 
Geometric correction performed with 6 Ground Control Points (geometric model RMSE: 0.181 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 report (SITES_U01-RGB_ASA_NYB_20180416.PDF)

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