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<br />Data transmissions are processed on a real-time basis. Raw data are <br />converted into engineering units and time stamped. Discharge and contents <br />values are computed from stage data utilizing stage-discharge and <br />stage-contents table conversions. Shifts are automatically applied to account <br />for changes in the stream channel characteristics affecting stage-discharge <br />relationships as identified from actual on-site measurements. Other <br />computations are made as necessary including stage-discharge conversions <br />utilizing Parshall flume equations, incremental precipitation, and <br />temperature. At the end of each 24-hour period, mean daily values are <br />computed and archived in a separate data base file. <br /> <br />Maintaining data base integrity is a primary operations goal. Real-time <br />data are of no value unless the data are accurate. Considerable effort is <br />maintained to ensure that the remote hardware/sensor interface remains in <br />calibration. This effort becomes compounded by the fact that nearly 6S% of <br />the stations in the state's monitoring network are operated by other entities <br />that generally are not utilizing the data to make real-time decisions. <br />Stations are typically visited by a hydrographer on a 2 to 4 week interval. <br />On-site measurements are made along with any necessary calibrations. Normal <br />data ranges for each station are entered into the central computer. If data <br />values fall outside of the expected range, they are flagged accordingly. <br />Flagged values are not utilized in computing mean daily values. Each day the <br />computer reports the number of "data quality" flags for each station. <br /> <br />Data editing may be done to either IS-minute resolution data or the mean <br />daily values. Editing is done on a separate working file duplicated from the <br />original data base. In this fashion, the integrity of the real-time data is <br />maintained. Data editing privileges, along with the ability to input data <br />processing/data conversion commands, are restricted to authorized users. User <br />name/password combinations carry limited privileges as determined by the <br />system's data base manager. <br /> <br />The Division of Water Resources is responsible for system maintenance. <br />Field personnel from each Division received training from Sutron technicians <br />in the operations and maintenance of the system hardware. Two staff engineers <br />received a week of special training at Sutron's facilities in Herndon, <br />Virginia, Training was directed at system diagnostics, hardware calibration, <br />and basic repairs. Each Division is supplied with a minimum of two sets of <br />replacement hardware. If a component malfunctions and cannot be repaired in <br />the field, that component is replaced and returned to the manufacturer for <br />repair. <br /> <br />Computer generated system diagnostics reports assist in monitoring the <br />operating qualities of the remote data collection hardware. The report <br />tabulates the operations characteristics for each station for the previous <br />day. The report lists the number of received, scheduled, and missed <br />transmissions, any message length errors, transmission time errors, errors in <br />transmission quality including power (EIRP) and frequency, any deficiency in <br />remote power supplies, and the number of missing values and parity errors for <br />each station. Frequently, hardware operating problems can be detected before <br />reaching a critical (non-operative) stage. <br /> <br />-15- <br />