sight2perpdist:
Convert sight distance and sight angle to perpendicular distance.
Description
When distance data are collected on line transects using sight distances and
sight angles, they need to be converted to perpendicular distances before
analysis.
Usage
sight2perpdist(sightdist, sightangle)
Arguments
sightdist
Distance from observer
sightangle
Angle from center line. In degrees between 0 and 180.