7.2 Loading FRF data

A similar process is used for loading and plotting FRF data as with the operational data. The FRF Data card shows basic information for all imported data, such as name, status (if imported or loaded), type, size, and bandwidth.

Importing FRF data

You can import FRF data in two ways:

• Clicking on + and browsing for the data
• Dragging and dropping the data

Importing a DIRAC project

You can directly import a DIRAC project in SOURCE, without previously exporting it. During the import, an import dialog will appear, in which you can select the desired datasets from all the matrix presets. You can also import geometries, and define and review the channel types that are based on the Description field of the senors and excitations. A time block dataset is optionally added to the Operational Data module, with the raw time data of the impacts.

FRFs imported from DIRAC

If the FRF data are loaded from a DIRAC project (export) specifically, several FRF datasets may be available within a single file. The nomenclature used for the names of these datasets is the following:

• Measured ($$ \mathbf{{Y}_{uf}} $$): contains raw, untransformed FRF data that were obtained in the measurement;
• VP ($$ \mathbf{{Y}_{qm}} $$): contains data in which both forces and responses have been transformed to the Virtual Point(s);
• Force-VP ($$ \mathbf{{Y}_{um}} $$): contains data in which the forces have been transformed to the Virtual Point(s), while the responses are left unchanged. This dataset is most often used for in-situ Blocked Force TPA;
• User defined ($$ \mathbf{{Y}_{Custom}} $$): contains data with a custom selection of channels and reference channels, some of which may be transformed to the Virtual Point(s).

The types of data available in the specific file will depend on how the export settings were chosen in the DIRAC project.

Loading data

SOURCE uses a “lazy loading” procedure that allows you to import the data’s header information before actually loading all of the (potentially very large) data. To load the data, right-click on the desired file and press Load data. When it is loaded, the status will turn from grey to green. It is also possible to unload data by right-clicking on the file and selecting Unload data.