data units: radians, strain, micro-strain, or nano-strain

[andreas-wuestefeld]

Does anyone has opinions (and arguments) for or against using as native unit

• radians
• strain
• micro-strain
• nano-strain
• ...

As geophysicist I prefer physical units. Using radians also requires the introduction of another header value for the scaling.
units other than strain [m/m] may allow going for lower-precission formats of the data matrix

[gloverha]

One bit of info that might be necessary is the original unit for data collection. Some instruments output phase and others provide phase rate. We've been exploring how phase v phase rate impacts channel fading. So, it seems like important info to include in metadata.

[andreas-wuestefeld]

Thanks gloverha
The latest iteration of the format actually incorporates that idea. a new required header field describes the unit of the data on disk.
An additional scale factor is also provided, with a new unit-string after conversion