ser2beh: downsample series data to faux behavior data

In williamcioffi/sattagutils: utils for manupulating sat tag output

downsample series data to faux behavior data

Description

a simple downsampling which takes series data stream as an input and creates an estimate of what the behavior stream would have looked like. tries to interpolate surfacing times for more accurate duration estimates.

Usage

ser2beh(
  s,
  surface_threshold_meters = 25,
  vrate_ascent_meters_per_second = 1.4,
  vrate_decent_meters_per_second = 1.4,
  dive_definition_threshold_meters = 50,
  period
)

Arguments

s	a series data stream or a dataframe approximating one. requires columns numeric Date, numeric Depth, numeric DRange.
vrate_ascent_meters_per_second,	vrate_decent_meters_per_second these are the vertical ascent and decent rates used to interpolate surfacing times. defaults are for Ziphius cavirostris (see notes).
dive_definition_threshold_meters	would be from the behavior settings you want to emulate. this is the threshold to qualify as a behavior dive.
period	sampling period of input series data
surface_threshold_metersused	by the peak finding algorithm to determine if a peak is close enough to the surface to represent a real surfacing event. default 25 is for me. you will need ot pick something that makes sense for your species.

Note

i've set the vertical ascent and decent rates the same for Ziphius cavirostris (1.4 m/s). This is based on some experimentationwith known surfacings from behavior data, vertical rates from series data, and analysis of dtags by Tyack et al. (2006). Though the ascent rates are much slower for Z. cavirostris after deep dives than the decent rates, there is actually no difference in the last several hundred meters and the rate is much faster.

References

Tyack, P. L., Johnson, M., Soto, N. A., Sturlese, A., & Madsen, P. T. (2006). Extreme diving of beaked whales. Journal of Experimental Biology, 209(21), 4238–4253. https://doi.org/10.1242/jeb.02505

williamcioffi/sattagutils documentation built on June 3, 2022, 10:21 a.m.