| Description: The chosen method for the CISSCAL bias subtraction. Bias subtraction removes the CCD's zero-exposure signal (bias) either by subtracting the BIAS_STRIP_MEAN from the image header or by fitting a line to the overclocked pixels. This entry also details which method was chosen for the 2Hz noise removal. There are two possible options for removing this noise. The first uses the overclocked pixel array. The second uses the dark sky areas in the image itself. In either case, the 2Hz background is inferred by taking the average or median value for each line in conjunction with low-pass filtering |
| Namespace Id: cassini | Steward: atm | Class Name: ISS_Calibrated_Attributes | Type: ASCII_Short_String_Collapsed |
| Minimum Value: None | Maximum Value: None | Minimum Characters: 1 | Maximum Characters: 255 |
| Unit of Measure Type: None | Default Unit Id: None | Attribute Concept: None | Conceptual Domain: SHORT_STRING |
| Status: Active | Nillable: false | Pattern: None |
| Permissible Value(s) | Value | Value Meaning |
| | Subtracted 2Hz noise (image mean) | Subtracted noise via a calculated 2Hz signal. |
| | Subtracted 2Hz noise (overclocked pixels) | Subtracted noise via the overclocked pixel array. |
| | Subtracted bias (BIAS_STRIP_MEAN) | Subtracted bias level via the BIAS_STRIP_MEAN value from the image's VICAR header. |
| | Subtracted bias (overclocked pixels) | Subtracted bias level via the overclocked pixel array. |