Bias Subtraction

Overview

The code can perform bias subtraction using input bias frames or by analyzing and subtracting off an estimate from the overscan region(s). The default for ARMLSD is to use bias frames and require that several be provided. A future implementation will combine the two approaches.

Methods

Subtract Bias Frame

This method combines the set of input bias frames and subtracts the resulting MasterBias from all other frames. This is the default in ARMLSD when bias frames are provided. It can be explicitly enforced by adding:

bias useframe bias

to the PypeIt reduction file.

Subtract Overscan

Analyze the overscan region and subtract a replicated version of the result from the full image. This method is applied by adding:

bias useframe overscan

to the PypeIt reduction file.

Overscan Algorithms

SavGol, Polynomial