Vis Shutter Model Product

Metadata

Data product name	DpdVisShutterModel
Data product custodian	VIS
Name of the Schema file	euc-vis-ShutterModel.xsd
Processing Element(s) creating/using the data product	ShutterModel
Processing function using the data product	VIS

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

The VIS shutter takes around 3 seconds to move. This results in a difference in exposure time along the X axis of the FPA.

The shutter model is a JSON file containing coefficients of the polynom for the correction, with the zero-order term first.

The correction will be applied the following way:

\[pixel_{corrected}(x) = pixel(x) * EXPTIME / (EXPTIME + P(x))\]

with x the pixel coordinate on the FPA.

The model is created by comparing stars in short and nominal exposures in the SelfCalibration field and derivate the polynomial fit of the following formula along the FPA:

\[S = (I_1*t_2 - I_2*t_1)/(I_2-I_1)\]