Time Offset Correction

Time offsets can be applied to a measurement site and they affect loaded time series data and exclusions. The process of applying time offsets is completely editable and reversible: no changes are made to the underlying loaded data so complete traceability is maintained in awkward jobs with time offsets!

There are two definitions of time in WindFarmer: Analyst:

Corrected Time:

The times displayed after application of time offsets. Corrected Time is used in:

  • All exported data

    • Exported time series

    • ExportStats stats files and other calculations exporting times.

    • Exclusions exported to file.

  • Procedure reports (except calibrations and time offsets)

  • Data cleaner

  • Any exclusions

Loaded Time:

The timestamps printed in files you load in to WindApp (plus any time offset applied in the data loader). All time stamped data is stored in this format underneath so you can edit time offsets later. The following are specified in Loaded Time:

  • Calibrations (definition and reporting)

  • Time offsets (definition and reporting)

  • Times presented during data loading (e.g. overlapping data comparisons)

Application of Time offsets

Time offsets can be applied to any time series. They are applied after calibrating it in the so when you view time series in the data cleaner and or use a time series in a procedure all time offsets will be included (e.g. in ExportStats).

The same time offsets are also applied to any exclusions which fall within the time offset start and end. The shifted exclusions are displayed in the data cleaner, exclusions export file, and exclusions lists in the project info report and “Clean-by-value > View Exclusions” window.

Please note…

  1. You can also apply a time offset in the data loader. This is intended to allow you to fix known time offsets early on, for example if a logger stamps data at 10:03, 10:13 etc. and you wish to remove 3 minutes from the time stamps on import. This time offset cannot be undone.

Time offsets and exclusions

When you edit, create and delete exclusions you do so in corrected time. As you edit exclusions we ensure that the exclusions will ALWAYS apply to the same data points even if you edit, remove or add time offsets.