stella.auxiliary

Interface Focussing

All Known Implementing Classes:

AbstractFocussingUnit, LinearPrimeFocus, MomentsFocussing

public interface Focussing

A focussing unit should be able to provide means of using the ancillary camera on a focus star to do an auto-focus routine. It should be able to provide a fast, crude method, that possibly only relies on temperature, a more sofisticated, but still coarse method, that may be implemented as a Zernike algorithm, and a fine method, which may be a FWHM minimization method. All methods should be able to return an error estimate and a FWHM estimate.

Author:

wooz

Method Summary

Modifier and Type	Method and Description
Vector2D	coarseFocus(double crude, CcdDriver aux, Star focus, ExposureTimeProviding etc, TransparencyMeasuring haze) Returns the coarse focus estimate.
Vector2D	crudeFocus() Returns the crude, i.e., temperature-model of the focus.
Vector2D	fineFocus(double coarse, CcdDriver aux, Star focus, ExposureTimeProviding etc, TransparencyMeasuring haze) Returns the fine focus.
double	getFwhm(CcdDriver aux, Star focus, ExposureTimeProviding etc, TransparencyMeasuring haze) The estimate of the FWHM in pixel at the current focus position.
Vector2D	scanFocus(CcdDriver aux, Star focus, ExposureTimeProviding etc, TransparencyMeasuring haze) This method scans for a focus.
boolean	setFocus(double mm) Sets the focus to the specified value, in system-depending units.
boolean	setFocusOffset(double mm) Offsets the focus to the specified value, in system-depending units.

Method Detail

setFocus

boolean setFocus(double mm)
          throws FocussingException

Sets the focus to the specified value, in system-depending units.

Throws:

FocussingException

setFocusOffset

boolean setFocusOffset(double mm)
                throws FocussingException

Offsets the focus to the specified value, in system-depending units.

Throws:

FocussingException

crudeFocus

Vector2D crudeFocus()
             throws FocussingException

Returns the crude, i.e., temperature-model of the focus. This should be a fast method which should not involve taking images, thus the method has no arguments.

Returns:

The focus position in x and its error estimate in y, zero for no error estimate possible.

Throws:

FocussingException

coarseFocus

Vector2D coarseFocus(double crude,
                     CcdDriver aux,
                     Star focus,
                     ExposureTimeProviding etc,
                     TransparencyMeasuring haze)
              throws FocussingException

Returns the coarse focus estimate. Should be quite fast and should normally involve taking two images (intra and extra focal).

Parameters:

crude - The best focus estimate from the crude model.

aux - The ancillary camera to use for the focus sequence.

focus - The focus star, already in the field of the camera.

etc - The exposure time calculator.

haze - Possible raw-time exposure increase due to clouds.

Returns:

The focus position in x and its error estimate in y, zero for no error estimate possible..

Throws:

FocussingException

fineFocus

Vector2D fineFocus(double coarse,
                   CcdDriver aux,
                   Star focus,
                   ExposureTimeProviding etc,
                   TransparencyMeasuring haze)
            throws FocussingException

Returns the fine focus. This is a slow method and can involve taking several images around an expected focus position.

Parameters:

crude - The best focus estimate from the crude/coarse model.

aux - The ancillary camera to use for the focus sequence.

focus - The focus star, already in the field of the camera.

etc - The exposure time calculator.

haze - Possible raw-time exposure increase due to clouds.

Returns:

The focus position in x and its error estimate in y.

Throws:

FocussingException

scanFocus

Vector2D scanFocus(CcdDriver aux,
                   Star focus,
                   ExposureTimeProviding etc,
                   TransparencyMeasuring haze)
            throws FocussingException

This method scans for a focus. Extremely slow.

Parameters:

aux - The ancillary camera to use for the focus sequence.

focus - The focus star, already in the field of the camera.

etc - The exposure time calculator.

haze - Possible raw-time exposure increase due to clouds.

Returns:

The focus position in x and its error estimate in y.

Throws:

FocussingException

getFwhm

double getFwhm(CcdDriver aux,
               Star focus,
               ExposureTimeProviding etc,
               TransparencyMeasuring haze)

The estimate of the FWHM in pixel at the current focus position.