| 摘要 |
PROBLEM TO BE SOLVED: To more surely upload observation data which is acquired on a slave unit disposed on an observation target position.SOLUTION: A GNSS receiver 22 creates observation data using a GNSS signal which is received on a GNSS antenna 23. A wireless LAN control part 24 controls wireless communication. A memory 26 stores the observation data. A control part 21 performs storage control of the observation data to the memory 26, and upload control to the wireless LAN control part. In addition, if uploading by radio communication is failed, the control part 21 stores the observation data which could not be uploaded well in the memory 26. If it is detected that uploading by radio communication is constructed again, the control part 21 sequentially reads out pieces of observation data which could not be updated and stored in the memory 26, in a latest order of time from the observation data created newly following to latest observation data, for performing upload control.SELECTED DRAWING: Figure 1 |
