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Sample EOVSA Data

Data are here. Here are some things to consider when working with the data:

  • Antennas 1-8 and 12 have a wide sky coverage, while antennas 9-11 and 13 are the older equatorial mounts that can only cover +/- 55 degrees from the meridian. All antennas were tracking for the flare, but for portions of the all-day scan (roughly before 1600 UT or after 2400 UT) only 9 antennas will be tracking. Data for non-tracking antennas is NOT flagged, so if you try to image these periods, you'll need to manually omit ants 9-11 and 13.
  • Because of the 2.5 GHz high-pass filters, data are taken only for bands 4-34. These will be labeled spectral window (spw) 0-31 in the measurement sets. However, band 4 (spw 0) is currently not calibrated, so only the 30 spectral windows 1-31 (bands 5-34, or frequencies 3-18 GHz) are valid data. You'll need to omit spw 0 when making images.
  • In principle, circular polarization should be valid and meaningful, but no polarization calibration has been done (yet) so no non-ideal behavior (leakage terms, etc.) have been accounted for.

Flare Data

Folder Flare_20170910 contains two measurement sets at full 1-s time resolution, each with 10-min duration:

  1. IDB20170910154625.corrected.ms (171 MB) [1] containing the first 10 minutes of the flare (15:46:25-15:56:25 UT), calibrated but no self-calibration
  2. IDB20170910154625.corrected.ms.xx.selfcaled (66 MB) [2] self-calibrated data for polarization XX
  3. IDB20170910155625.corrected.ms (232 MB) [3] containing the second 10 minutes of the flare (15:56:25-16:06:25 UT)
  4. IDB20170910155625.corrected.ms.xx.selfcaled (77 MB) [4] self-calibrated data for polarization XX

All Day Quiet Sun/Active Region Data

Folder AR_20170710 contains 8 calibrated measurements sets at 60-s time resolution.

  1. The seven UDB20170710*.corrected.ms are files for each scan separately, ranging in size from 7 - 150 MB depending on the length of the scan.
  2. UDB20170710_allday.ms (268 MB) [5] is the same data concatenated into a single file. However, each scan has a separate source ID.

The AR data are also calibrated but not self-calibrated. In fact, we need to create a strategy for self-calibration of such data. You can get an overview of the AR coverage on that day by looking at the plot at http://ovsa.njit.edu/flaremon/daily/2017/XSP20170710.png. The separate scan files above are labeled with the time of the start of the scan, and each scan covers the time of continuous solar data between each calibration scan.