All data downloaded from loggers together with relevant metadata (logger‐information, bird status, biometry, breeding status, etc.) are processed and analysed by the SEATRACK staff and stored in a database. The data collected are the shared property of SEATRACK and partners, and the data is tagged with the name of the partner as “Data responsible”.
Logger data is processed and stored in standardized tables (e.g positional data, light-level data, immersion data, sea surface temperature) that are linked with each other and relevant metadata through shared IDs.
Raw datafiles are also stored in a file archive as unprocessed data but with standardized names.
Data processing
Light-level geolocators
Positional data from light-level recordings
Geolocator data can produce on average two positions each date. Geolocators primarily record ambient light, which in turn can be used to time the occurrence of night and daytime. From this, timing of each approximate noon and midnight can be used to estimate a longitudinal position, and the approximate length of each day or night can be used to produce a latitudinal position. However, the accuracy is low, and the margin of error is generally considered to be in the tens to hundreds of kilometers, varying on several factors such as time of the year, latitude and shading of the logger (due to e.g. the animals behaviour, weather …).
