Data Processing
Firetail features a growing set of data processing capabilities. You can access these features via the Data menu (v1.0.0 and above).
Overview
(see below for details)
| Menu Item | Category | Description |
|---|---|---|
| Default Color | Color Track by | Use the default color for the trajectory. |
| Point Index | Color Track by | Highlight timestamps by an equidistant index. Time intervals are neglected. |
| Timestamp | Color Track by | Highlight timestamps with respect to the time intervals among them. |
| Speed over Ground | Color Track by | Highlight each timestamp by measured speed over ground. |
| Height | Color Track by | Color each timestamp relative to its associated height |
| Temperature | Color Track by | Show the measured temperature for each timestamp |
| Battery Voltage | Color Track by | Show the voltage available to the tracking device for each timestamp |
| DBBMM Average Window Variance *) | Color Track by | show the track’s utility distribution calculated from a dynamic Brownian Bridge Movement Model |
| Location Data Smoothing Layer | Manipulate Locations | apply curve smoothing trajectory |
| Calibrate e-obs IMU Data | Analyze Data | calibrate Inertial Measurement Unit data for e-obs tags |
| Calculate DBBMM | Analyze Data | calculated a dynamic Brownian Bridge Movement Model |
*) Requires Calculate DBBMM
Point Index/Timestamp
In the default viewport there no indication is given whether a timestamp has been measured earlier, or later. Using point index or timestamp will visually highlight early (black) points from late (white) measurements. While the point index uses equally distributed colors along the complete track, the timestamp mode will scale the colors according to their distance.
Speed/Height/Temperature/Battery Voltage
The respective attribute is color-coded by its maximal (white) and minimal (black) values for each timestamp.
DBBMM
(This is an experimental feature in Firetail v1.0.0)
The dynamic brownian bridge movement model provides means to estimate the utility distribution from a set of locations and timestamps. It was originally published by Kranstauber et al., 2012 [1] as a combination of Brownian Bridges (Horne et al., 2007 [2]) and behavioural change pattern estimation (Gurarie et al., 2009 [3]).
Firetail computes the utility distribution from the currently active set of timestamps via Calculate DBBMM.
The associated heatmap can be shown by DBBMM Average Window Variance.
Location Smoothing
Animal tracks can be smoothed to approximate real-life flight patterns and movement routes. Notably, this feature may displace the current trajectory significantly. It is useful to simulate more natural patterns at the cost of actual measurement accuracy.
References
- Kranstauber, B., Kays, R., LaPoint, S. D., Wikelski, M., & Safi, K. (2012). A dynamic Brownian bridge movement model to estimate utilization distributions for heterogeneous animal movement. Journal of Animal Ecology, 81(4), 738-746.
- Horne, J. S., Garton, E. O., Krone, S. M., & Lewis, J. S. (2007). Analyzing animal movements using Brownian bridges. Ecology, 88(9), 2354-2363.
- Gurarie, E., Andrews, R. D., & Laidre, K. L. (2009). A novel method for identifying behavioural changes in animal movement data. Ecology letters, 12(5), 395-408.