CCDTest_TDI_Linearity
Description :
This function allows to compute CCD linearity
using two image files, a flat field file and an image file, where
the CCD was exposed to light during readout process (this is why
this is called TDI method). The light exposition occurs when 5% of
the CCD has been readout.
It outputs the detector non linearity figures (Rms and p-p) as well
as two plots showing linearity residuals and linearity curve.
Please refers to this
link to know more about this function.
Minimum version : 3.00
Syntax :
CCDTEST_TDI_LINEARITY X1 Y1 X2 Y2 Offset FluxMin Filter ImageTDI$ ImageFlat$ Title$ DoPlots_Lin DoPlots_Res FirstLineY RMSLinearity P_PLinearity
Variables :
| Parameters | Inputs / Outputs | Type | Description |
| X1 | Input | Integer | First image column to process, please avoid prescan |
| Y1 | Input | Integer | Last image column to process, please avoid overscan |
| Y1 | Input | Integer | First row to process, this row must be illuminated |
| Y2 | Input | Integer | Last row to process at the top of the image, this row must be illuminated |
| Offset | Input | Floating point | Offset value in the area in the bottom that has not received any light, must be accurate. |
| FluxMin | Input | Floating point | This is the minimum light flux that will be used to compute the lowest light level of linearity, and thus will set the FirstLineY to be used. |
| Filter | Input | Floating point | If 0 no low pass filter is applied to the image, if 4 high low pass filter is performed to the data, allowing to be less sensitive to noise. |
| ImageTDI$ | Input | String chars | Full qualified path and filename of the TDI image |
| ImageFlat$ | Input | String chars | Full qualified path and filename of the flat field image file |
| Title$ | Input | String chars | Provides a Title for the two plots, usually the CCD's name. |
| DoPlots_Lin | Input | Boolean (0 or 1) | If 1 displays a plot showing linearity plot |
| DoPlots_Res | Input | Boolean (0 or 1) | If 1 displays a plot showing linearity residuals |
| FirstLineY | Output | Integer | This returns the first valid row that has been used during computation |
| RMSLinearity | Output | Floating point | Gives the RMS linearity computed throughout the first row and the last valid row |
| P_PLinearity | Output | Floating point | Gives the peak to peak linearity computed throughout the first row and the last valid row |
Image type that can be used by this function :
| Image name | Monochrome / RGB | Integer coding / Floating point / Complex | CPA / FITS file format |
| Img | Yes / No | Yes / Yes / No | Yes / Yes |
Script sample :
PathTDI$="C:\Prism\ESO\TDI-1-WO.cpa"
PathFlat$="C:\Prism\ESO\Flat-1-WO.cpa"
X1=28
X2=536
//
Light starts here
Y1=200
// and endshere
Y2=2045
Title$="TEST"
DoPlot_res=1
DoPlot_lin=1
OffsetADU=1010
FluxMinADU=50
LinA_FitFilter=3
CCDTEST_TDI_LINEARITY X1 Y1 X2 Y2 OffsetADU FluxMinADU LinA_FitFilter PathTDI$ PathFlat$ Title$ DoPlot_res DoPlot_lin FirstLineY RMSLinearity PPLinearity
Print
"FirstLineY = " FirstLineY
Print "RMSLinearity = " RMSLinearity
Print "PPLinearity = " PPLinearity