Transponder module for determination of a crossing time in a measuring system

A measuring system for measuring a crossing time, comprising:

• a low-frequency transmitter configured to transmit a low-frequency electromagnetic field signal via a transmission antenna disposed at a level of a line of passage;
• a decoder configured to receive at least one measurement signal from each transponder module of at least one transponder module when the transponder module is near the line of passage;
• and
• the at least one transponder module, each being carried by a corresponding moving object and comprising:
• a low-frequency signal receiver configured to receive the electromagnetic field signal via a receiving antenna, each of the at least one transponder module being woken up when said low-frequency electromagnetic field signal is received,
• a microcontroller configured to receive a receipt signal from the low-frequency signal receiver,
• a transmitter linked to the microcontroller and configured to transmit, via a high-frequency antenna, at least one measurement result in a high-frequency measurement signal,
• a time base in the microcontroller, the time base not being synchronized with the decoder and being activated to begin measurement of a local time upon receipt of the low-frequency electromagnetic field signal,
• wherein, after receiving the receipt signal, the microcontroller of each transponder module of the at least one transponder module is configured to,
• measure and store several successive intensities of the electromagnetic field signal in order to reconstruct an electromagnetic field curve,
• calculate a crossing time of the transponder module in units of the local time measured by the activated time base, based on the reconstructed electromagnetic field curve, and
• transmit, to the decoder, a transmission time together with the calculated crossing time, the transmission time being equal to a value of the local time measured by the time base of the transponder module when the crossing time and the transmission time are transmitted, and
• wherein the decoder is configured to receive the crossing time at a receiving time, and convert the received crossing time in the units of the local time measured by the time base into a time of day, based on the receiving time, the transmission time, and the received crossing time.