Fig. 7From: How to improve the accuracy of height data from bird tracking devices? An assessment of high-frequency GPS tracking and barometric altimetry in field conditionsRelative change of the proportion of positions within the collision risk height range (50–200 m) in marsh harriers (black) and red kites (red) when applying different degrees of bias (trueness) or noise (precision) to the height data. Points represent empirical error distributions found in different GPS tag models in either GPS or barometric height data from either low-frequency or high-frequency sampling. Lines represent gradually increasing bias for trueness and increasing noise based on theoretical error distributions (exponential or normal) for precision. Expon. exponential, MaH marsh harrier, RK red kite, Baro barometric, LF low-frequency, HF high-frequencyBack to article page