I work on an intercomparison of tides measurements. The measures come from different tides gauges whose two campbell sensors : CS455 (pressure sensor) and CS476 (radar sensor).
In starting to process the data, I realized that the radar sensor CS476 had a problem. It's shifted in time. it's a shift of several minutes : 6 at 7. It always 6 minutes ahead of the other sensors.
The 2 sensors are connected at the data logger CR1000, but the problem not come from to the data logger, otherwise the CS455 would also shift.
The sensor could it have its own internal clock? I do not see other solutions.
Thanks for your help. And sorry for my English!