Apply Bias Value
The Apply Bias Value method is used by the Calibrate Images command to apply a bias correction to images. This is used to correct the bias signature, especially important for CCD images. In this method, the bias is specified as a single value to be applied uniformly to the entire image. This method may be used in conjunction with the Apply Bias Frame method to effect a 2 step bias removal process.
The bias value may be specified in 2 ways:
To use a specific numeric value, click the Value option and enter the value into the field beside it.
To obtain the value from the image header, click Keyword and enter the name of the keyword. Names like REFBIAS, BIASVAL, FATZERO, ZERO, and ERASE are some of the keyword names that have historically been used for this quantity.
Create Bias Frame, Apply Bias Frame, Calibrate Images, Methods Page