AIA_GET_RESPONSE Version 6 Release Notes 2014-May-8 Paul Boerner boerner ~at~ lmsal ~dot~ com What's new in this version: * The temperature response functions have been updated to use CHIANTI v7.1.3 (version 4 used CHIANTI v7.1) * The effective area (wavelength response) functions have not changed. * The evenorm and timedepend_date corrections have been updated based on EVE v4 calibration updates (previous AIA versions relied on EVE v2). * The "chiantifix" was adjusted to account for the updated EVE calibration As before, if you wish to access an older version of the instrument calibration or temperature response, you can set the VERSION, EMVERSION and RESPVERSION keywords in AIA_GET_RESPONSE --------------------------------------------------------------------------------- AIA_GET_RESPONSE Version 4 Release Notes 2013-February-19 Paul Boerner boerner ~at~ lmsal ~dot~ com What's new in this version: * The temperature response functions have been updated to use CHIANTI v7.1 (version 2 and 3 used CHIANTI v7.0) * The effective area (wavelength response) functions for the EUV channels have been extended to cover the range from 25 to 900 A, based on Soufli et al., Proc SPIE Sept 2012 (doi:10.1117/12.927274) (Previously the EUV channel effective area stopped at 425 A). * The temperature response functions were updated to reflect the extension of the effective area definition * The "chiantifix" was adjusted to account for the move to CHIANTI 7.1 * Some bugs in AIA_GET_RESPONSE and the underlying routines were fixed (these bugs were the type to cause crashes, rather than bad results) As before, if you wish to access an older version of the instrument calibration or temperature response, you can set the VERSION, EMVERSION and RESPVERSION keywords in AIA_GET_RESPONSE --------------------------------------------------------------------------------- AIA_GET_RESPONSE Version 3 Release Notes 2012-September-18 Paul Boerner boerner ~at~ lmsal ~dot~ com What's new in this version: * The data underlying the effective area (wavelength response) have not changed * An error was introduced to the continuum calculation used for the emissivity in V2; this was fixed for V3. * The time-dependent corrections introduced in V2 were updated for V3. Note that the time-dependent corrections are themselves now time-dependent. That is, for images taken recently, the current response is estimated by extrapolating recent trends in the effective area to the present date. This estimate may change when better cross-calibration measurements spanning the date in question become available. If you wish to access an older version of the degradation correction, set the RESPVERSION keyword to the date of the desired version (the date can be found in the .corrections.time.version_date field of a response structure returned by AIA_GET_RESPONSE) --------------------------------------------------------------------------------- AIA_GET_RESPONSE Version 2 Release Notes 2012-February-06 Paul Boerner boerner ~at~ lmsal ~dot~ com What's new in this version: * The data underlying the effective area (wavelength response) have not changed * The data underlying the emissivity (CHIANTI model) has been updated to use CHIANTI v7.0, to cover a broader wavelength range, and to fix a bug in the calculation of the continuum emissivity * The temperature response functions are calculated from the effective area and the emissivity, so they will reflect minor changes because of the revised emissivity * It is now required to specify either /DN or /PHOT to explicitly include or exclude the DN-per-photon correction * Several new keywords have been added to apply corrections to the response function (EVENORM, TIMEDEPEND_DATE, CHIANTIFIX) * There is improved self-documentation in the structures returned by this routine See Also: * An overview of the structure format returned by this routine is available at http://sohowww.nascom.nasa.gov/solarsoft/sdo/aia/response/README.txt * More detailed documentation on the empirical corrections to the 94 and 131 A channels is included at http://sohowww.nascom.nasa.gov/solarsoft/sdo/aia/response/chiantifix_notes.txt * The header of the routine itself has more documentation on how each keyword is used --------------------------------------------------------------------------------- Brief Overview of how to run AIA_GET_RESPONSE: To return the effective area (wavelength response) function: aiaresp = AIA_GET_RESPONSE(/dn) Note that you should specify whether you want to include the DN/photon conversion by setting either then /dn or /phot keyword. If you don't set either of those, the routine will ask what you want to do. The default is to include the DN/photon conversion; prior to this version 2 release, the default was not to include the conversion (and the routine did not ask if nothing was specified). There are a number of options that can be specified: /uv : Return response for the 1600/1700/4500 channels instead of the EUV channels /all : Include functions for both thin and thick focal plane filters /full : Include full detail on the components (mirrors, filters, etc.). Note that the resulting structure is formatted differently than the simple effective area structure /noblend: Don't include potential crosstalk between 2 channels on the same telescope (131/335, 94/304) version=: Currently only 2 versions are available; 1 is the preflight effective area, and 2 is the current release. There isn't any difference in the wavelength response functions. There are also some optional corrections to the effective area that can be applied by specifying keywords: /evenorm : Normalize the response to agree with observations from SDO/EVE on 1 May 2010 /timedepend_date : apply a time-dependent correction to account for on-orbit degradation (can be set as a switch, in which case the current date is used; or as a string specifying the time for which the correction is desired) Note that the time-dependent correction is calculated by trending AIA data vs. EVE. It generally makes sense to include /evenorm when you are looking at time dependence, so if you specify /timedepend_date but not /evenorm, the routine will check to make sure that's what you want to do (unless you also explicitly set evenorm=0). These corrections are included in a substructure of the effective area function: aiaresp = AIA_GET_RESPONSE(/dn, /evenorm, /time) help, aiaresp help, aiaresp.corrections aiaresp = AIA_GET_RESPONSE(/dn, /evenorm, /time, /full) help, aiaresp Note that the CORRECTIONS substructure is included and populated whether or not you request the corrections to be applied to the effective area. Help on the wavelength response structure: * Version is a new field; it is an integer (currently either 1 or 2) * Date is the date on which the response function was retrieved * The effective area for each channel can be accessed from either the .all array at the top of the response structure, or from the substructure corresponding to each channel. For example, the 94 A effective area can be read from aiaresp.all[0,*] or aiaresp.a94.ea * The full response structure also includes a filedate field which specifies the date on which the underlying data files were last updated. This should be 20100804_232510 for both version 1 and version 2 of the effective area * The full response structure has elecperev and elecperdn fields in each of the wavelength substructures (e.g. aiaresp.a94_full.elecperev). These are used to calculate the photon-to-DN conversion when the /dn keyword is set * The wavelength response can be used, along with a spectrum, to predict an instrument count rate using AIA_BP_MAKE_COUNTS_SPEC To return the emissivity (CHIANTI) function: emiss = AIA_GET_RESPONSE(/emiss) The following options are available: /full : Include exhaustive detail on the CHIANTI calculation, including a line list (array of structures describing each emission line) version= : Currently there are only 2 emissivity versions available; 1 is the preflight emissivity, and 2 is the current release. The current release uses a newer version of the CHIANTI database (7.0 vs. 6.0.1), fixes a bug in the calculation of the continuum, and covers a broader wavelength range. Help on the emissivity structure: * Version is a new field; it is an integer (currently either 1 or 2) * Note that documentation on how CHIANTI was run (ionization balance, abundance, pressure, etc) is included in the CH_INFO substructure (or the GENERAL substructure if the full model was run) * The emissivity can be turned into a model spectrum using AIA_BP_EMISS2SPEC To return the temperature response function: aiatresp = AIA_GET_RESPONSE(/dn, /temp) The temperature response function is generated by first retrieving the wavelength response (effective area), and then folding it with the spectral model (emissivity). Note that many of the keywords and notes listed above for the effective area apply for the temperature response as well: /all, /noblend, /evenorm, /timedepend_date These keywords are applied to the effective area before it is used to generate the temperature response function The following keywords work slightly differently: /uv : the temperature response of the UV channels is not calculated by this routine /full : As with the wavelength response, this option returns full detail on the temperature response. However, it does not include the component calibration information; instead, it includes the matrix of wavelength and temperature that is flattened to produce the temperature response version=: Applies to both the wavelength response and the emissivity model. If you wish to use different versions for the wavelength response, set version to the wavelength response version that you want to use, and set emversion to the version of the emissivity that you want. emversion= : Version of the emissivity to use (only specify if you want a different version of emissivity and wavelength response) And there is an additional correction that can be applied to the temperature response function: /chiantifix : If set, an empirical correction is applied to the temperature response of the 94 and 131 channels in order to try to account for emission that is known to be missing in CHIANTI. The details of the correction are included in the CORRECTIONS sub-structure Help on the temperature response structure: * The temperature response can be used, along with a DEM, to predict an instrument count rate using AIA_BP_MAKE_COUNTS_DEM * Note that documentation on how CHIANTI was run (ionization balance, abundance, pressure, etc) is included in the EMISSINFO substructure