Calculated columns

[NikoSimisiroglou]

Hello,

I am trying to find out how to handle logger Calculated columns within the IEA task 43 schema.

Some loggers e.g. Kintech have calculated columns. There are three types of columns, analog columns (ANL), frequency ones (FRQ) and calculated ones (CALC). An example of the usage of a calculated one is when you assosciate a Geovane with a Wind Vane. The geovane produces a column dirgcor (ANL or FRQ) ,this is an offset with respect to True North estimated by the Geovane that needs to be applied to the associated wind vane (ANL) to estimate the true wind direction (referenced to True North) . Calc is then the sum of the two columns.

[stephenholleran]

Hi @NikoSimisiroglou ,

Sorry for the slow response. I was at WESC last week.

A few questions:

1. Why do you need to know if a column is calculated? We don't distinguish between analog or freq columns.
2. Could you use the notes to inform the consumer that it is calculated?

FYI; This has come up previously in relation to calculated soiling loss in solar from @abohara and also to distinguish VMM data from measured #214 (comment) . However, it would be good to understand why you need it for the scenario you outline so whatever solution we come up with will be appropriate?

Cheers,

[kersting]

@stephenholleran I think this is in the context of the geovane. The sensor generates the offset to true north as one column, but certain loggers get that information, and the raw data from the wind vane, and generate a calculated column that has both the true north offset and the raw wind direction combined. This would be a calculated column that is in the logger but it is not just the output of one instrument but the combination of 2 instruments in one column.

@NikoSimisiroglou please let me know if I missed anything.

[abohara]

@kersting @stephenholleran @NikoSimisiroglou

This did come up prior in the context of Solar ( lots of calculated columns there ) and also frequent in some loggers like Campbell.

We had a discussion on this topic ( can't find the issue to point to ) , but I recall the solution we agreed on was to add a field in the logger_measurement_config table, is_calculated as a way to differentiate what might be raw_measurements and what are calculated

[stephenholleran]

Hi @abohara,

The discussion was on the 11-Aug-2022 #129 (comment)
You were to start a branch with the is_calculated field added.