Vis Non Linearity Model Product

Metadata

Data product name	DpdVisNonLinearityModel
Data product custodian	VIS
Name of the Schema file	euc-vis-NonLinearityModel.xsd
Processing Element(s) creating/using the data product	VIS - NonLinear Calibration
Processing function using the data product	VIS – Processfield correction.

Proposed for inclusion in EAS/SAS

Yes

Data product elements

Header	object of type sys:genericHeader
Data	object of type vis:visFileContainerData
QualityFlags	object of type dqc:sqfPlaceHolder
Parameters	object of type ppr:genericKeyValueParameters

Detailed description of the data product

Non Linearity Model is a JSON file containing a dictionary with one item per quadrant. This Model is produced by the Non Linearity Calibration pipeline.

There are currently two different non-linearity correction formats:

• A up to 5th order polynomial which converts the non-linear signal to a linear signal.

• A series of points pairing a linear signal value with its corresponding non-linear signal.

Both formats can’t be mixed in the same product.

Curently (VIS PF-17), we use a TVAC model with a series of points pairing.

For the polynomial model, coefficients are stored in numpy.poly1d() convention, in decreasing powers, starting from the highest degree.

Example of the polynomial product:

"1-1.E": [
  1.6737016148821795e-32,
  -2.27198105837953e-27,
  9.851909684187759e-23,
  -1.3871686911278604e-18,
  1.0000000000000022,
  -1.204531435924529e-11
],