How to improve the accuracy of height data from bird tracking devices? An assessment of high-frequency GPS tracking and barometric altimetry in field conditions

Table 1 Overview of the sources of error in GPS and barometric height data, either regarding the determination of height above ground itself or regarding the identification of stationary periods on the ground on which we based our assessment of vertical accuracy

Source of error	GPS height	Barometric height
Determination of height above ground
GPS height above geoid/ellipsoid	X
Air pressure measurement		X
Weather data		X
Simplifications in barometric height formula		X
Horizontal GPS position	X	X
Digital elevation model	X	X
Identification of stationary periods on the ground
GPS speed	X	X
Classification of stationary/flight positions	X	X
Habitat classification	X	X

ISSN: 2050-3385