Sunspot Solar Observatory Consortium Data Products (SSODA)

SSODA Available Data Products

The following data products are availabe through SSODA. Questions or clarifications on data processing steps should be directed to the Support Astronomer, Dr. Sean Sellers (sellers at nmsu.edu).

IBIS (Until August 2019)

The Interferometric BI-dimensional Spectropolarimeter (IBIS) was operated as a consortium setup instrument from 2017 until mid-2019. The primary data products obtained during this time were dual-beam spectrocopic measurements of the 8542Å, 6563$#8491;, and 5896Å spectral lines. On a limited basis, other spectral lines, or full-stokes polarimetry may have additionally been obtained. IBIS data levels are defined as:

• Level-0: Unprocessed and uncalibrated datacubes, with individual wavelength tunings stored in successive FITS extensions.
• Level-1: IBIS level-1 data have been corrected for known instrumental effects, including gain and the blueshift induced by etalon tilt. Additionally, IBIS level-1 data have been destretched, with the spectroscopic images destretched relative to the cotemporal wideband channel. Unless otherwise notes, prefilter corrections have not been carried out.

Citing IBIS Data

In addition to the SSODA archive paper, the following should be cited when publishing results based on archival IBIS data:

• Cavallini, F., 2006, IBIS: A New Post-Focus Instrument for Solar Imaging Spectroscopy, Sol. Phys., 236, 415-139.
• Reardon, K.P., Cavallini, F., 2008, Characterization of Fabry-Perot Interferometers and Multi-Etalon Transmission Profiles. The IBIS Instrumental Profile. A&A, 481,978-912.
• Righini, A., Cavallini, F., Reardon, K.P., 2010, Imaging Performance of Multi-Etalon Bidimensional Spectrometers, A&A, 515, A85.
• If the IBIS-A Archive is used: Ermolli, I., et.al., 2022, IBIS-A: The IBIS data Archive, A&A, 661, A74.

ROSA/Zyla

The Rapid Oscillations in the Solar Atmosphere (ROSA) camera system (including the Zyla Rapid H-alpha Dynamics Camera) is an array of up to six synchronized cameras operated as a consortium instrument. The primary data products obtained are rapid imaging in a selection of the G-band (4300Å), 4170Å continuum, 3500Å continuum, Ca K 3934Å, Hydrogen-β 4861Å, and Hydrogen-α 6563Å.

The Hydrogen-α line is typically captured in the newer Zyla camera, a 2048x2048 CMOS array. while the other bands are typically captured in some combination of Andor 1002x1004 arrays. The Zyla camera usually has a field size of 173", while the smaller Andor arrays usually have a field size of 58". This is subject to change, depending on the target of observations, and will be noted in the level-1 FITS headers. Data levels for the ROSA system are defined as:

• Level-0: Unprocessed and uncalibrated. ROSA raw files are stored in fits or fits.fz (compressed) format, with up to 256 data extensions. Zyla raw files are by default stored in unformatted binary, but may have been repacked as fits.fz files for storage considerations.
• Level-1: ROSA/Zyla Level-1 data have been gain corrected and speckle-burst reconstructed via the KISIP v6 code to remove atmospheric distortion. This results in a reduction in cadence, as a stack of images are combined in the process. Depending on the cadence and atmospheric conditions during observations, the final burst may be constructed from 16, 32, or 64 (typical) images. Level-1 data are packed as FITS files
• Level-1.5: Data have been destretched. The final destretch is performed using a running reference image stack on each successive frame. The destretch algorithm is an iterative, subfield-based, spline destretch algorithm, with an additional module that detrends solar flows on timescales of minutes. When available, both the flow-preserving and regular destretch data are made available in FITS format.

Citing ROSA/Zyla Data

In addition to the SSODA archive paper, the following should be cited when publishing results based on archival ROSA/Zyla data:

• Jess, D.B., et. al., 2010, ROSA: A High-cadence, Synchronized Multi-camera Solar Imaging System, Sol. Phys., 261, 363-373

FIRS

The Facility InfraRed Spectropolarimeter is a rastering spectropolarimeter with cotemporal slit-jaw imaging. The obtained data product is full-stokes spectropolarimetry of the He I 10830Å line triplet, and nearby photospheric lines. The typical optical setup results in a slit length of 75", and a slit width of 40um (0.3"). Rastering is typically done densely, with slit positions spaced to be exactly contiguous. Deviations from this will be noted. FIRS data levels are defined as:

• Level-0: Unprocessed and uncalibrated. FIRS raw files are fits format, and consist of the 8 polarimetric states used by the instrument.
• Level-1: FIRS data have been calibrated for gain and polarization induced by telescope optics. Data at this level typically show signs of fringing and prefilter spectral deformations. Level-1 data are saved in a combination of IDL .sav format and binary.
• Level-1.5: FIRS data at this level have been corrected for prefilter effects, de-fringed from same-day disk-center fringe maps, and wavelength calibrated from the FTS spectral atlas. Stokes QUV spectra are stored as QUV/I. Evidence of fringes may still exist at longer wavelengths, as the correction is biased towards the 10830Å He I complex. Data at this level are stored in FITS files, and formatted to be similar to IRIS level-3 datacubes for users who are familiar with that instrument. Level-1.5 data are ready for spectropolarimetric inversion with only a minimum of work required.
• Level-2: On a limited basis, we make available the results of spectropolarimetric inversions using the Hazel code. These data are stored in FITS format and contain derived physical quantities, such as magnetic field vectors. Level-2 data may contain inversions of the He I triplet, the Si I photospheric line, or both.

Citing FIRS Data

In addition to the SSODA archive paper, the following should be cited when publishing results based on archival FIRS data:

• Jaeggli, S.A., et. al., 2010, FIRS: A new instrument for photospheric and chromospheric studies at the DST, MmSAI., 81, 763

SPINOR/HSG

The Spectro-Polarimeter for INfrared and Optical Regions (SPINOR) instrument is a rastering spectropolarimeter with cotemporal slit-jaw imagaing. The obtained data product is full-stokes spectropolarimetry of a configurable selection of lines, typically the Ca II 8542Å, He I D3 5896Å, and Fe I 6302Å lines. When operated without polarimetric capabilities, the instrument is referred to as the Horizontal Steerable Grating (HSG). SPINOR/HSG data levels are defined as the following:

• Level-0 Unprocessed and uncalibrated. SPINOR/HSG raw files are fits format, and consist of datacubes containing the polarimetric states used by the instrument at each slit position.
• Level-1 SPINOR/HSG data have been calibrated for gain and polarization induced by telescope optics. SPINOR/HSG data at this level are stored in IDL sav format, readable in python by the scipy.io.readsav function. SPINOR data at this level shows signs of fringing. There is currently no widely applicable method to correct for these fringes, and this step must be done raster-by-raster. For advice with SPINOR fringe correction, contact the support astronomer. Alternately, if you would like to donate approximately $70,000 for high-quality LCVRs and cameras to solve this problem, please contact the support astronomer.

Citing SPINOR Data

In addition to the SSODA archive paper, the following should be cited when publishing results based on archival SPINOR data:

• Socas-Navarro, H., et. al., 2006, Spinor: Visible and Infrared Spectro-Polarimetry at the National Solar Observatory, Sol. Phys., 235, 55-73.