Impact directions of detected particles compared with the directions of simulated trails for comets 72P/D-F and 45P/H-M-P in the spacecraft-centric reference frame in ecliptic coordinates. Blue dots show the approach directions of simulated trail particles. Red diamonds indicate the sensor orientation during the time of particle impact; the ecliptic longitude of the data point is the spacecraft spin orientation at the time of particle impact while the ecliptic latitude corresponds to the maximum of the sensor sensitivity profile in latitudinal direction (Grün et al. 1980). Red crosses indicate the approximate sensor field of view (cf. Fig. 8), and small black crosses show the impact direction of particles orbiting the Sun on circular orbits at the heliocentric distance of Venus. The detection time of the impact is given in the top left corner of each panel.