I could perceive the ship coming over the horizon.
source: WordNet 3.0
become conscious of
She finally perceived the futility of her protest.
source: WordNet 3.0
To obtain knowledge of through the senses; to receive impressions from by means of the bodily organs; to take cognizance of the existence, character, or identity of, by means of the senses; to see, hear, or feel; as, to perceive a distant ship; to perceive a discord.