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CR2RE Pipeline Reference Manual 1.6.7
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Function to compute the Strehl ratio on an image. More...
Functions | |
| hdrl_parameter * | hdrl_strehl_parameter_create (double wavelength, double m1_radius, double m2_radius, double pixel_scale_x, double pixel_scale_y, double flux_radius, double bkg_radius_low, double bkg_radius_high) |
| Creates Strehl Parameters object. | |
| cpl_boolean | hdrl_strehl_parameter_check (const hdrl_parameter *self) |
| Check that the parameter is a Strehl parameter. | |
| double | hdrl_strehl_parameter_get_wavelength (const hdrl_parameter *p) |
| Access the wavelength in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_m1 (const hdrl_parameter *p) |
| Access the primary mirror radius in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_m2 (const hdrl_parameter *p) |
| Access the obstruction radius in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_pixel_scale_x (const hdrl_parameter *p) |
| Access the image X pixel scale in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_pixel_scale_y (const hdrl_parameter *p) |
| Access the image Y pixel scale in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_flux_radius (const hdrl_parameter *p) |
| Access the total flux radius in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_bkg_radius_low (const hdrl_parameter *p) |
| Access the background region internal radius in the Strehl parameter. | |
| double | hdrl_strehl_parameter_get_bkg_radius_high (const hdrl_parameter *p) |
| Access the background region external radius in the Strehl parameter. | |
| cpl_parameterlist * | hdrl_strehl_parameter_create_parlist (const char *base_context, const char *prefix, hdrl_parameter *par) |
| Create parameter list for the Strehl computation. | |
| hdrl_parameter * | hdrl_strehl_parameter_parse_parlist (const cpl_parameterlist *parlist, const char *prefix) |
| Parse parameter list to create input parameters for the Strehl. | |
| hdrl_strehl_result | hdrl_strehl_compute (const hdrl_image *himg, hdrl_parameter *params) |
| This function computes the Strehl ratio. | |
Function to compute the Strehl ratio on an image.
The most commonly used metrics for evaluating the AO correction is the Strehl ratio. The Strehl ratio is defined as the ratio of the peak image intensity from a point source compared to the maximum attainable intensity using an ideal optical system limited only by diffraction over the telescope aperture. The Strehl ratio is very frequently used to perform the quality control of the scientific data obtained with the AO assisted instrumentation.
The calculation is performed by calling the top-level function hdrl_strehl_compute() and the parameters passed to this function can be created by calling hdrl_strehl_parameter_create().
| hdrl_strehl_result hdrl_strehl_compute | ( | const hdrl_image * | himg, |
| hdrl_parameter * | params | ||
| ) |
This function computes the Strehl ratio.
| himg | input hdrl image |
| params | input hdrl parameters |
The raw image is assumed to be pre-processed to remove the instrument signatures (bad pixels, etc.) and the natural noise sources (sky background, etc.). Nethertheless this function allows also the user to correct a residual background by setting the parameters bkg_radius_low, bkg_radius_high. The PSF is identified and its integrated flux (controlled by the parameter flux_radius) is normalized to 1. The PSF baricenter is computed and used to generate the ideal PSF (with integrated flux normalized to 1) which takes into account the telescope pupil characteristics (radius m1, central obstruction, m2, ...), the wavelength wavelength, at which the image has been obtained and the related pixel scale (pixel_scale_x, pixel_scale_y,). Finally the Strehl ratio is computed dividing the maximum intensity of the image PSF by the maximum intensity of the ideal PSF and the associated error is also computed.
Definition at line 1326 of file hdrl_strehl.c.
| cpl_boolean hdrl_strehl_parameter_check | ( | const hdrl_parameter * | self | ) |
Check that the parameter is a Strehl parameter.
| self | The parameter to check |
Definition at line 221 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| hdrl_parameter * hdrl_strehl_parameter_create | ( | double | wavelength, |
| double | m1_radius, | ||
| double | m2_radius, | ||
| double | pixel_scale_x, | ||
| double | pixel_scale_y, | ||
| double | flux_radius, | ||
| double | bkg_radius_low, | ||
| double | bkg_radius_high | ||
| ) |
Creates Strehl Parameters object.
| wavelength | Nominal filter wavelength [m] |
| m1_radius | primary mirror radius [m] |
| m2_radius | obstruction radius [m] |
| pixel_scale_x | image X pixel scale in [arcsec] |
| pixel_scale_y | image Y pixel scale in [arcsec] |
| flux_radius | radius used to sum the flux [arcsec] |
| bkg_radius_low | radius used to determine the background [arcsec] |
| bkg_radius_high | radius used to determine the background [arcsec] |
Definition at line 188 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_parse_parlist().
| cpl_parameterlist * hdrl_strehl_parameter_create_parlist | ( | const char * | base_context, |
| const char * | prefix, | ||
| hdrl_parameter * | par | ||
| ) |
Create parameter list for the Strehl computation.
| base_context | base context of parameter (e.g. recipe name) |
| prefix | prefix of parameter, may be an empty string |
| par | hdrl_parameter defining the defaults |
Creates a parameter list with the Strehl parameters:
The CLI aliases omit the base_context.
Definition at line 360 of file hdrl_strehl.c.
References hdrl_strehl_parameter_check(), hdrl_strehl_parameter_get_bkg_radius_high(), hdrl_strehl_parameter_get_bkg_radius_low(), hdrl_strehl_parameter_get_flux_radius(), hdrl_strehl_parameter_get_m1(), hdrl_strehl_parameter_get_m2(), hdrl_strehl_parameter_get_pixel_scale_x(), hdrl_strehl_parameter_get_pixel_scale_y(), and hdrl_strehl_parameter_get_wavelength().
| double hdrl_strehl_parameter_get_bkg_radius_high | ( | const hdrl_parameter * | p | ) |
Access the background region external radius in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 331 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_bkg_radius_low | ( | const hdrl_parameter * | p | ) |
Access the background region internal radius in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 317 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_flux_radius | ( | const hdrl_parameter * | p | ) |
Access the total flux radius in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 303 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_m1 | ( | const hdrl_parameter * | p | ) |
Access the primary mirror radius in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 247 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_m2 | ( | const hdrl_parameter * | p | ) |
Access the obstruction radius in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 261 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_pixel_scale_x | ( | const hdrl_parameter * | p | ) |
Access the image X pixel scale in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 275 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_pixel_scale_y | ( | const hdrl_parameter * | p | ) |
Access the image Y pixel scale in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 289 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| double hdrl_strehl_parameter_get_wavelength | ( | const hdrl_parameter * | p | ) |
Access the wavelength in the Strehl parameter.
| p | The Strehl parameter |
Definition at line 233 of file hdrl_strehl.c.
Referenced by hdrl_strehl_parameter_create_parlist().
| hdrl_parameter * hdrl_strehl_parameter_parse_parlist | ( | const cpl_parameterlist * | parlist, |
| const char * | prefix | ||
| ) |
Parse parameter list to create input parameters for the Strehl.
| parlist | parameter list to parse |
| prefix | prefix of parameter name |
Reads a parameter list in order to create Strehl parameters.
Expects a parameter list containing:
Definition at line 448 of file hdrl_strehl.c.
References hdrl_join_string(), and hdrl_strehl_parameter_create().