| 摘要 |
A remote sensing system comprises a sensor unit 12 including sensor means 14, a memory 18, a timer 20 and a transmitter 16, and a monitoring unit 10 including a receiver, the sensor unit 12 being operable, at intervals determined by the timer 20, to transmit data to the monitoring unit 10. The memory 18 is operable to store at least one previously transmitted sensor reading, and the data transmitted to the monitoring unit 10 comprises both new, previously untransmitted data and data representative of the previously transmitted sensor reading from the memory 18. The transmitted data may comprise new data and the previous three or more sensor readings. Error detection may be further enhanced by check-sum digit encoding and receive antenna selection diversity 22. Transmissions from different sensors may be at randomly selected points around the sample period. |
