1. A method for acquiring a radionavigation signal carrying a spreading code with a period that is at least 10 times longer than a correlation time, comprising: obtaining a baseband radionavigation signal based on converting the radionavigation signal to an intermediate frequency radionavigation signal and sampling and converting the intermediate frequency radionavigation signal to the baseband radionavigation signal on a delay line, and correlating the baseband radionavigation signal with a local spreading code replica so as to identify a time delay between the spreading code of the baseband radionavigation signal and the local spreading code replica in a temporal alignment search space; wherein, in order to correlate the baseband radionavigation signal with the local spreading code replica, m spreading code sequences are generated where m is greater than 1, each of said m spreading code sequences being of a same duration, equal to a duration of the baseband radionavigation signal, and said m spreading code sequences are associated with consecutive m time hypotheses spaced by the correlation time in the temporal alignment search space, each of said m spreading code sequences is correlated with the baseband radionavigation signal in a respective correlation operation among m correlation operations, said m correlation operations being executed in parallel for each of said m spreading code sequences associated with the m time hypotheses spaced by the correlation time.