RHESSI Mission Archive


RHESSI was in operation for more than 16 years, from February 2002 to April 2018, recording over 120,000 X-ray events over more than a complete 11-year solar cycle. We are generating the Mission Archive products listed below in order to facilitate current analysis of RHESSI observations, and to ensure continued use of the RHESSI science data in years to come. The Mission Archive should be completed by the end of 2023. The deep repository of the archive will be at the Solar Data Analysis Center (SDAC) at Goddard.

Click the image below to see the distribution and duration of flares throughout the RHESSI mission:

Note: This page and most of the products listed below are currently under development.

Status: Complete

The detector health database provides a snapshot of the status of the front and rear segments of the nine RHESSI detectors at a resolution of one day. Six criteria were examined for each detector segment - off, voltage change, noisy data, unsegmented, and missing data (described in more detail here). The results are stored both in computer-readable csv files and monthly plot files showing green (good), amber (some problems), and red (do not use) indicators for each day for each of the 18 detector segments. The csv text files can be queried by the RHESSI software to determine good detector segments for a specified time; the routines are described here.

Status: Completed first pass

High quality images have been generated for every flare in the RHESSI flare catalog that meets time and flux thresholds. For each flare, an imagecube was generated on a grid of times and energies optimized for that flare, using six of the RHESSI image reconstruction algorithms. The RHESSI Image Archive Strategy describes the organization of the archive and determination of imagecube parameters. The Guide to RHESSI Image Archive describes the interface to the archive, both the monthly listings of flares and the single-flare web page for each flare, explains how to use the FITS files in the archive, and discusses each type of plot available in the archive in detail.

The first pass was made using the roll angle information and flare catalog in place prior to 2021. Now that an improved roll angle database has been completed for the full mission (as of July 2021), the imagecubes for the flares with incorrect positions in the first pass will be reprocessed.

Energy Spectra

Status: In progress

Three types of energy spectrum FITS files and their corresponding detector response (SRM) files will be generated.

Standard energy resolution (Complete through 2015)

  • For every orbit of the RHESSI mission (midnight-to-midnight), we are generating count spectrum files with 4s bins, 77 energy bins 3-250 keV, combining all functional detectors. For every flare, we are also generating SRM files using the same energy bins and the same combined detectors as in those spectrum files.

High energy resolution (Waiting for final calibration)

    For the larger RHESSI flares (events seen above 50 keV), we are generating count spectrum files for the orbit containing the flare (midnight-to-midnight) for each separate functional detector, with 4s time bins and native energy bins. The corresponding SRM files will also be provided.

Gamma-ray events (Waiting for final calibration)

    For the less than 20 RHESSI gamma-ray flares, we will generate spectrum and SRM FITS files at appropriate energy and time binning, as well as FITS files of suitable background for each flare.

In addition, we hope to provide spectral analysis results for the ~230 largest flares observed by RHESSI (in progress).

Visibility Archive

Status: Completed First Pass

Two types of visibility FITS files are being generated for all flare time intervals.

Time/energy bins same as in image archive (Complete)

  • As the image archive was being made, we saved the visibility files used to make the images for the visibility-based reconstruction algorithms. Please see the RHESSI Image Archive Strategy for how the time and energy bins were determined.

Finer resolution time/energy bins (Complete)

  • For each flare, we are generating visibility FITS files at 8s time resolution (nominally, depends on attenuator state changes), in up to 20 energy bins pre-defined as [3,6,7,8,10,11.1,12,15,20,25,30,40,50,60,70,85,100,125,150,200,300] keV (the highest energy bin depends on the flare) using all functional detectors (front segment only). In the RHESSI image object software, these time and/or energy bins can be combined as desired by the user.

The first pass was made using the roll angle information and flare catalog in place prior to 2021. Now that an improved roll angle database has been completed for the full mission (as of July 2021), the visibility files for the flares with incorrect positions in the first pass will be reprocessed.

Solar Aspect System Calibrated Archive

Status: Complete

SAS limb and image data

  • Orbital FITS files containing the SAS limb data and daily FITS files containing the SAS image data are provided for the full RHESSI mission. Documentation on the SAS data files will be provided soon.

Gamma-ray Burst Database

Status: In progress

Terrestrial Gamma-ray Flash (TGF) Database

Status: In progress

Products that are used internally by the RHESSI software

Calibration Database

Status: In progress

Update and complete existing spectrometer calibration databases:

  • Gain/offset
  • Spectral resolution
  • Low-energy threshold for events ("slow threshold")

Create two new databases (TBD):

  • Recover-ramp-rejection parameters
  • Low-energy threshold for triggers ("fast threshold")

Roll Angle System Calibrated Database

Status: Complete

Provides a verified roll angle database for the full mission.

Please include the following acknowledgement if you use these data in a paper or presentation:
"We acknowledge the use of the RHESSI Mission Archive available at https://hesperia.gsfc.nasa.gov/rhessi/mission-archive."