This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
data:data_analysis_manual [2021/06/30 10:54] eric buchlin [Find data] change link |
data:data_analysis_manual [2022/03/31 23:56] Peter Young [SPICE instrument and capabilities] |
||
---|---|---|---|
Line 11: | Line 11: | ||
SPICE papers: | SPICE papers: | ||
* Instrument paper: //Astron. Astrophys.//, **642**, A14, 2020. [[https://doi.org/10.1051/0004-6361/201935574|DOI]], [[https://ui.adsabs.harvard.edu/abs/2020A%26A...642A..14S|ADS]] | * Instrument paper: //Astron. Astrophys.//, **642**, A14, 2020. [[https://doi.org/10.1051/0004-6361/201935574|DOI]], [[https://ui.adsabs.harvard.edu/abs/2020A%26A...642A..14S|ADS]] | ||
- | * First results: Submitted | + | * First results: //Astron. Astrophys.//, **656**, A38, 2021. [[https://doi.org/10.1051/0004-6361/202141221|DOI]], [[https://ui.adsabs.harvard.edu/abs/2021A%26A...656A..38F/abstract|ADS]] |
* In-flight calibration: Not available yet | * In-flight calibration: Not available yet | ||
* Other papers can be found in the [[https://ui.adsabs.harvard.edu/public-libraries/rIi8Zx4zTg2stP5nTojx2Q|SPICE ADS library]] | * Other papers can be found in the [[https://ui.adsabs.harvard.edu/public-libraries/rIi8Zx4zTg2stP5nTojx2Q|SPICE ADS library]] | ||
Line 27: | Line 27: | ||
The full SPICE data set (to be cited in papers) has a DOI: [[https://doi.org/10.5270/esa-lbmdy7c|doi:10.5270/esa-lbmdy7c]]. DOIs will also be attributed to each data release. | The full SPICE data set (to be cited in papers) has a DOI: [[https://doi.org/10.5270/esa-lbmdy7c|doi:10.5270/esa-lbmdy7c]]. DOIs will also be attributed to each data release. | ||
+ | |||
+ | When browsing the SPICE catalog and archive you will see the following codes: | ||
+ | |||
+ | **n-ras**: a raster scan with one of the narrow slits (2", 4" or 6")\\ | ||
+ | **w-ras**: a raster scan with the wide slit (30")\\ | ||
+ | **n-sit**: a sit-and-stare study with one of the narrow slits\\ | ||
+ | **w-sit**: a sit-and-stare study with the wide slit\\ | ||
+ | **n-exp**: a single exposure with a narrow slit that yields the entire spectrum\\ | ||
+ | **w-exp**: a single exposure with the wide slit that yields the entire spectrum | ||
+ | |||
+ | For the "ras" data, the FITS file contains a single raster scan. If the raster is repeated, then each repeat goes in a new file. | ||
+ | |||
+ | Rasters can be performed in the "exp" mode, but each exposure will end up in a different FITS file. | ||
===== Find data ===== | ===== Find data ===== | ||
UiO catalogue: | UiO catalogue: | ||
* Can be generated with IDL/SolarSoft (SSW) from a local data tree: | * Can be generated with IDL/SolarSoft (SSW) from a local data tree: | ||
- | - Make sure $SPICE_DATA points to the data tree you want to have catalogued | + | - Make sure ''$SPICE\_DATA'' points to the data tree you want to have catalogued |
- | - Run SPICE_GEN_CAT. The catalogue file will be written to the data tree root directory (you need to have write access) | + | - Run SPICE\_GEN\_CAT. The catalogue file will be written to the data tree root directory (you need to have write access) |
- | - Run SPICE_CAT | + | - Run SPICE\_CAT |
* The catalogue file generated from all SPICE files is accessible [[http://astro-sdc-db.uio.no/vol/spice/fits/spice_catalog.txt|through the UiO website]] (restricted to SPICE team) | * The catalogue file generated from all SPICE files is accessible [[http://astro-sdc-db.uio.no/vol/spice/fits/spice_catalog.txt|through the UiO website]] (restricted to SPICE team) | ||
* How to use it in [[data:data_analysis_manual:read_catalog_python|Python]] | * How to use it in [[data:data_analysis_manual:read_catalog_python|Python]] | ||
Line 47: | Line 60: | ||
In the future: VSO. VSO through SSW or sunpy. Sunpy/Fido | In the future: VSO. VSO through SSW or sunpy. Sunpy/Fido | ||
+ | ===== Tips and Advice on Analyzing SPICE Data ===== | ||
+ | |||
+ | ==== Doppler Maps ==== | ||
+ | |||
+ | WARNING: Doppler maps created from SPICE lines show unusual patterns that we believe are due to the point spread function of the instrument. Work is underway on a deconvolution procedure that will correct for this effect. If you need advice on features you see in a Doppler map, please contact the SPICE PI at frederic.auchere -at- universite-paris-saclay.fr or another member of the SPICE team. | ||
+ | |||
+ | ==== Burn-in Effects ==== | ||
+ | |||
+ | The SPICE detectors have microchannel plates (MCPs). Over time, the sensitivity of MCPs decreases at the locations of strong emission lines. This effect is referred to as "burn-in" and results in a flat-top or "self-reversal" to the line profile. This has already been noticed for the C III 977 line. The SPICE team plans to provide a correction to this effect once it is fully characterized. | ||
+ | |||
+ | ==== Flare lines ==== | ||
+ | |||
+ | The two key flare lines for EIS are Fe XVIII 974.86 and Fe XX 721.56 that are formed around 7 MK and 10 MK, respectively. The Fe XVIII line will probably be seen in active region cores (at least from bright active regions). | ||
+ | |||
+ | The Fe XVIII line is located between the stronger H I 972.54 (Lyman-gamma) and C III 977.02, but measurements should be possible. | ||
+ | |||
+ | The Fe XX line lies close to Fe VIII 721.26. One can estimate the strength of this line by comparing with Mg IX 706.06. The latter will be about a factor 10 stronger. | ||
+ | |||
+ | To determine if a flare is occurring at the time of a SPICE observation, check the STIX Data Browser at: | ||
+ | |||
+ | [[https://datacenter.stix.i4ds.net/view/plot/lightcurves | ||
+ | ]] | ||
===== Access data ===== | ===== Access data ===== | ||
Line 58: | Line 93: | ||
- | ===== Read an display data ===== | + | ===== Read and display data (IDL) ===== |
- | IDL: | + | External links: |
* Oslo's quicklook tools [[https://github.com/ITA-Solar/solo-spice-ql/wiki|spice_data, spice_object...]] | * Oslo's quicklook tools [[https://github.com/ITA-Solar/solo-spice-ql/wiki|spice_data, spice_object...]] | ||
+ | * Peter Young's [[https://pyoung.org/spice/analysis_guide.html|SPICE Analysis Guide]] | ||
+ | |||
+ | |||
+ | ==== Environment variables ==== | ||
+ | |||
+ | Choose a location to store your SPICE data (e.g., '/my_data/spice') and then point the environment variable ''$SPICE\_DATA'' to it: | ||
+ | |||
+ | ''setenv,'SPICE\_DATA=/my\_data/spice' | ||
+ | '' | ||
+ | | ||
+ | This line should be added to your IDL\_STARTUP file. | ||
+ | |||
+ | Data are organized under ''$SPICE\_DATA'' with a year/month/day subdirectory structure. See the "Ingesting downloaded data" section below. | ||
+ | |||
+ | |||
+ | ==== The SPICE catalog ==== | ||
+ | |||
+ | The SPICE catalog can be accessed by doing: | ||
+ | |||
+ | ''IDL> spice\_cat'' | ||
+ | |||
+ | Use the "SPICE\_GEN\_CAT" button to make sure you have the most up-to-date list. | ||
+ | |||
+ | ==== Reference data-sets ==== | ||
+ | |||
+ | Perhaps the most useful data from the early commissioning phase (before July 2020) are the raster scans on 28-May-2020. | ||
+ | |||
+ | 16:05, 16:50 - disk center rasters with 20s exposures \\ | ||
+ | 17:50, 18:35 - north limb rasters with 20s exposures\\ | ||
+ | 19:35, 20:20 - south limb rasters with 20s exposures\\ | ||
+ | 21:20, 22:05 - west limb rasters with 20s exposures\\ | ||
+ | 23:05, 23:47 - east limb rasters with 20s exposures | ||
+ | |||
+ | The first true science observations were obtained during 18 to 22 November 2020. For example, an active region can be seen in the raster beginning 19:57 UT on 18-Nov-2020. | ||
+ | |||
+ | ==== Ingesting downloaded data ==== | ||
+ | |||
+ | After you have downloaded some SPICE FITS files, you can ingest them into your data directory with spice\_ingest: | ||
+ | |||
+ | ''IDL> spice\_ingest, files'' | ||
+ | |||
+ | This routine automatically creates the sub-directory structure (year/month/day) within $SPICE\_DATA for the files. | ||
+ | |||
+ | ==== Finding and reading a FITS file ==== | ||
+ | |||
+ | Once a file has been ingested, then you can find it with spice\_find\_file using the observation time: | ||
+ | |||
+ | ''IDL> file=spice\_find\_file('28-may-2020 16:05')'' | ||
+ | |||
+ | A file can be read into an IDL object with: | ||
+ | |||
+ | ''IDL> d=spice\_object(file)'' | ||
+ | |||
+ | ==== Extracting information from the data object ==== | ||
+ | |||
+ | The table below gives some methods for extracting information out of the data object. Where "i" is given, it means the index of a wavelength window should be specified (indices begin at 0). | ||
+ | |||
+ | You can get a list of all methods by doing: | ||
+ | |||
+ | IDL> d->help | ||
+ | |||
+ | ^ Command ^ Function ^ | ||
+ | | d->get\_number\_windows() | No. of spectral windows | | ||
+ | | d->get\_window\_data(i,/load) | Extract a data window | | ||
+ | | d->get\_lambda\_vector(i) | Get wavelength vector for the window | | ||
+ | | d->get\_header(i) | Extract a data window header | | ||
+ | | d->get\_window\_id(i) | Get the data window ID | | ||
+ | | d->get\_start\_time() | Start time of observation | | ||
+ | | d->get\_end\_time() | End time of observation | | ||
+ | | d->get\_sit\_and\_stare() | Set to 1 if sit-and-stare observation | | ||
+ | | d->get\_number\_exposures() | Number of exposures in raster | | ||
+ | | d->get\_xcen(i) | Get the X-center for the window | | ||
+ | | d->get\_ycen(i) | Get the Y-center for the window | | ||
+ | |||
+ | |||
+ | ==== Quicklook tools ==== | ||
+ | |||
+ | A set of five widget-based tools are available for browsing SPICE data, and these can be accessed through spice\_xfiles: | ||
+ | |||
+ | '' IDL> spice\_xfiles'' | ||
+ | |||
+ | This allows you to select a FITS file from your SPICE data directory. A new widget appears from which you can then select one of the five quicklook tools: Detector, Raster Browser, Raster, Whisker and Intensity map. These tools mimic software that were available for EIS and IRIS. | ||
+ | |||
+ | For further details, please visit the [[https://github.com/ITA-Solar/solo-spice-ql/wiki|SPICE Quicklook and Data Analysis Software Page]]. | ||
+ | |||
+ | === Raster Browser === | ||
+ | |||
+ | This is useful for browsing the 3D data cubes from SPICE rasters. In addition to being called from spice\_xfiles (see above), it can also be called directly from the command line: | ||
+ | |||
+ | ''IDL> spice\_raster\_browser,file'' | ||
+ | |||
+ | Use a 3-button mouse to browse the images and spectra: the middle button allows you to select a new pixel, the left button zooms in and the right button zooms out. | ||
+ | |||
+ | ===== Read and display data (Python) ===== | ||
- | Python: | + | Links: |
* [[:data:data_analysis_manual:sunraster|with sunraster]]. | * [[:data:data_analysis_manual:sunraster|with sunraster]]. | ||