light level geolocation michael sumner phd. candidate
TRANSCRIPT
Light level geolocation
Michael SumnerPhD. candidate
Summary
• Light level geolocation
– Light data
– Environmental data
– Behavioural model
• Summarizing behaviour of multiple animals
• Calibrating tags
Tracking vertebratessouthern elephant seal
(male 5yo)
Photo:
J. van den Hoff, AAD
• Archival tag– Light level
– pressure (depth)– temperature– Archived on board
Light levels and solar elevation
Kingston, Tasmania April 2003
Time GMT
10 PM 8 AM 6 PM 2 AM 10 AM
8 AM 4 PM
Local time
LONGITUDE
time of noon in GMT
LATITUDE
length of day vs. night
LATITUDE
difference in length
of day versus night
Effect of longitude on expected light Effect of latitude on expected light
Locations for predicted light levels
DAWN DAWN
Light data – with solar elevation in Hobart (different y-scale)
Light data – choosing “twilight”
Real light data – diving elephant seal
Parameters to estimate – lon, lat, and light attenuation
Location estimates
• Storing series of estimates for animal “tracks”
Calibrating light tags