Lagged alternate measurement estimate

Already-existing meter or gas quality (GQ) data can be used to substitute for data that is missing from another meter or GQ point. This estimation method is not available for estimating irregular data.

Meter or GQ data from an alternate meter or GQ point from 'n' time periods in the past can be used as a substitute for a missing value. This is useful for check/custody meters, using upstream meters/GQ for estimations, or even estimations for a run in a multi-run station. It is possible to spread the meter or GQ data to reflect the same granularity, so that it reflects the same granularity as the incoming meter or GQ information. This makes it easier to see whether the two values corroborate one another.

To configure a lagged alternate estimation, the number of periods in the past must be defined. A period is defined by the granularity of the estimate. So when estimating an hour, the period is an hour. When estimating a day, the period is a day. If there is not a valid record, the first valid record going back in time is used. However, this can be disabled for meters so that only the exact time can be used. The following algorithm is used to determine the estimate:

Estimate = Alt Value * Factor +Offset

A factor and an offset can be specified that will be applied to the volume, energy, and mass for a meter and to the heating value for a GQ.