We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
AN ALGORITHM TO IMPROVE GEOLOCATION POSITIONS USING SEA SURFACE TEMPERATURE AND DIVING DEPTH.
- Authors
Beck, C.A.; McMillan, J.I.; Bowen, W.D.
- Abstract
The at-sea movement of marine mammals is an important component of their foraging ecology, but has been difficult to study. Geolocation timed-data recorders (GLTDRs) estimate positions using measured light level to calculate day length and local noon. It is well known that these location estimates are imprecise (mean error of >1°). Satellite telemetry generally provides a more accurate, but also more expensive means of monitoring movement. We evaluated the accuracy and precision of geolocation positions by comparing these locations with satellite data from Service Argos for eight free-ranging gray seals (Halichoerus grypus) equipped with both a satellite-linked data recorder (SDR) and a GLTDR. Geolocation positions differed by 1,026.0 ± 292.28 km from the corresponding Argos locations. We developed an algorithm to correct geolocation positions by comparing surface water temperature (ST) and dive depth collected by GLTDRs with existing sea-surface temperature and bathymetry databases. The corrected positions were significantly closer (P < 0.025) to the Argos locations of these seals (94.2 ± 8.22 km). The original geolocation positions would have led to incorrect conclusions about the use of space by gray seals; however, the corrected positions can be reliably used to study the large-scale spatial distribution of individuals.
- Subjects
MARINE mammals; ANIMAL ecology; ALGORITHMS
- Publication
Marine Mammal Science, 2002, Vol 18, Issue 4, p940
- ISSN
0824-0469
- Publication type
Article
- DOI
10.1111/j.1748-7692.2002.tb01083.x