Published May 11, 2021
| Version 3
Dataset
Restricted
Deception Island Chinstrap pengui GPS and TDR tracking data 2018-2019 processed and raw
Creators
- 1. Norwegian Polar Institute
- 2. University of Cape Town
- 3. INACh
- 4. DEA South Africa
Description
GPS data:
- 81 individuals with useable GPS tracks (removed 2 that had few points)
- Penguins have been instrumented between 29th November 2018 – 14th January 2019
- Captures were organised per round (8) at Bailey head + MAC point
- The GPS data have been preprocessed = Penguin_GPS_tidy
- Removed all Nas
- Removed locations with less than 4 satellittes
- Removed all locations that are positive (aka impossible)
- Match GPS data with penguins metadata
- Cut off by deployment date + 24h and by revovery date
- Removed D_R4_P10 that had a very high sampling rate (instrument failure?)
- Applied a speed filter (SDA filter)
- Build a CRAWL model for each track (no error model, couldn’t get it to work on GPS data with a constant error of 50m)
- Predicted regularly time spaced locations every 2 min based on the model (Penguin_GPS_tidyMOD)
- Penguin_GPS_tidy2 holds the clean dataset with the correct cut off dates at the start (right before the 1st trip and at the recovery date)
TDR data:
- 3(4) instrument types: Axy-trek (“regular” and AGM), Mk9 WC and LOTEK
- 64 dive files associated with GPS data
- Each have a different decoding software and result in a different .csv file
- Each file is loaded and saved into a separate .Rds environment
- Each file is cleaned for Nas and only the TDR columns are kept
- The records are ordered by date
- Dives calibration
- For LOTEK instruments, I took the mean of the surface points (all the positive values after changing the sign of depth aka a point below the surface has a negative depth value). The mean of the surface points was between 2.3 and 1.7 m . That was the offset for each instrument used in the calibrDepth function.
- downsampled each record to 1 point every 15 sec. I tested that over a few chunks of records and between 1 sec resolution and 15 sec we are retaining over 92% of the dives and the ones that are lost are mainly very shallow dives (<5m)
- For MAC point we have 34 913 dives from 5 animals