Water Quality Monitoring Results
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Extension Hardening was added to Excel 2007.
This blog post explains it in detail:
Extension Hardening
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During dredging there are two buoys and a water current detector positioned around the Dredge. One buoy is positioned upstream of the Dredge and the other downstream of it.
The current detector identifies which direction the water is flowing past the Dredge so that Upstream or Downstream can be assigned to each buoy. Each buoy has two turbidity
sensors, a high one near the surface of the water and another lower down. Turbidity readings are reported every fifteen minutes for each of the four sensors (DownstreamHigh, DownstreamLow, UpstreamHigh, UpstreamLow).
The Dredge contribution to turbidity is calculated as the largest value of the Downstream sensor minus the smallest value of the Upstream Sensor.
However, if the result is negative then it is reported as 0. Also when the current detector indicates no water flow, then the dredge contribution is reported as 0.
If the Upstream sensor is offline then turbidity is the largest value of the Downstream sensor.
If the Downstream sensor is offline then turbidity is -100000.0 which means that the sensor was offline during
that time period and no data was collected. Also, dredging should be stopped in this case.
All values for turbidity are in NTU.
The "Flags" column indicates the status of the sensors at the time of the reading. The following is the key for this column.
- S = At least one of the sensors is offline.
- G = The GPS was not working for at least one sensor.
- C = The current detector indicated no water flow.
- M = The current detector is offline. As a result, the dredge contribution is reported as the maximum reading from the four sensors and the downstream/upstream readings are reported as -100000.0.