Method and system for measurement of a crossing time, and transponder module for the system

A method for measurement of at least one crossing time at a line of passage of at least one moving object by a personalized transponder placed on the moving object, during a sports competition in a measuring system, which includes at least one transmitter of an electromagnetic field signal via an antenna disposed on the line of passage and circuitry configured to receive at least one measurement signal from each transponder in proximity to the line of passage, the method comprising:

• generating the electromagnetic field signal by the transmitter, the electromagnetic field signal comprising a modulation of a synchronization command at the start of each modulation repetition period;
• activating the personalized transponder on the first reception of the modulated synchronization command in the electromagnetic field signal;
• measuring the intensity of the electromagnetic field signal without modulation captured by the transponder once activated and synchronized, at regular time intervals;
• and
• transmitting directly via the transponder each intensity measurement or a packet of intensity measurements to the circuitry that determines a crossing time of the line of passage on the basis of variation in the electromagnetic field intensity of the measurements received from the transponder.