A sensing system including a sensor terminal configured to store measured sensor data in a packet and to wirelessly transmit the packet, and a data collection terminal configured to collect the sensor data by receiving the packet and to transfer the sensor data to an upper network, wherein the sensor terminal comprises: a real-time clock circuit configured to count, by a counter, a sensor clock generated by the sensor terminal itself, and thereby outputting a count value that repeats a monotonous change within a predetermined numerical value range; characterised in that the sensor terminal comprises a sensor control circuit configured to periodically transmit the packet in synchronism with the change in the count value, and to transmit the count value by adding the count value to the packet, and the data collection terminal comprises: a reference clock generation circuit configured to generate a reference clock synchronized with a reference time acquired from the upper network; and a collection control circuit configured to acquire a value of the reference clock from the reference clock generation circuit in accordance with reception of the packet, and to store the value in a storage circuit as a time stamp representing an arrival time of the packet, wherein the collection control circuit is configured to perform statistical processing of time stamps concerning a plurality of packets received and count values added to the plurality of packets, and to recalculate the time stamps concerning the packets based on a packet transmission interval obtained from the statistical processing and a reference arrival time representing an arrival time of a head packet. a real-time clock circuit configured to count, by a counter, a sensor clock generated by the sensor terminal itself, and thereby outputting a count value that repeats a monotonous change within a predetermined numerical value range; characterised in that the sensor terminal comprises a sensor control circuit configured to periodically transmit the packet in synchronism with the change in the count value, and to transmit the count value by adding the count value to the packet, and the data collection terminal comprises: a reference clock generation circuit configured to generate a reference clock synchronized with a reference time acquired from the upper network; and a collection control circuit configured to acquire a value of the reference clock from the reference clock generation circuit in accordance with reception of the packet, and to store the value in a storage circuit as a time stamp representing an arrival time of the packet, wherein the collection control circuit is configured to perform statistical processing of time stamps concerning a plurality of packets received and count values added to the plurality of packets, and to recalculate the time stamps concerning the packets based on a packet transmission interval obtained from the statistical processing and a reference arrival time representing an arrival time of a head packet. a reference clock generation circuit configured to generate a reference clock synchronized with a reference time acquired from the upper network; and a collection control circuit configured to acquire a value of the reference clock from the reference clock generation circuit in accordance with reception of the packet, and to store the value in a storage circuit as a time stamp representing an arrival time of the packet, wherein the collection control circuit is configured to perform statistical processing of time stamps concerning a plurality of packets received and count values added to the plurality of packets, and to recalculate the time stamps concerning the packets based on a packet transmission interval obtained from the statistical processing and a reference arrival time representing an arrival time of a head packet.