  The Yarkovsky effect is a weak non-gravitational force leading to a small
variation of the semi-major axis of an asteroid. Using radar measurements and
astrometric observations, it is possible to measure a drift in semi-major axis
through orbit determination. This paper aims to detect a reliable drift in
semi-major axis of near-Earth asteroids (NEAs) from ground-based observations
and to investigate the impact of precovery observations and the future Gaia
catalogue in the detection of a secular drift in semi-major axis. We have
developed a precise dynamical model of an asteroid's motion taking the
Yarkovsky acceleration into account and allowing the fitting of the drift in
semi-major axis. Using statistical methods, we investigate the quality and the
robustness of the detection. By filtering spurious detections with an estimated
maximum drift depending on the asteroid's size, we found 46 NEAs with a
reliable drift in semi-major axis in good agreement with the previous studies.
The measure of the drift leads to a better orbit determination and constrains
some physical parameters of these objects. Our results are in good agreement
with the 1/D dependence of the drift and with the expected ratio of prograde
and retrograde NEAs. We show that the uncertainty of the drift mainly depends
on the length of orbital arc and in this way we highlight the importance of the
precovery observations and data mining in the detection of consistent drift.
Finally, we discuss the impact of Gaia catalogue in the determination of drift
in semi-major axis.
