Around the time of conjunction when the spacecraft go behind the sun relative to Earth, science return is significantly reduced. This period runs from 19 Aug 2014 (1 Dec 2014) for Ahead (Behind) until Jan.2016 for both spacecraft. There are four levels of reduced data for this period: Sidelobe 1 at 5330 bps for SECCHI, Sidelobe 2 at 1005 bps, 34m at 364 bps, and OFF. Details of this period may be found on the SSC Website. Following are details of the SECCHI observing program.
During this period, image telemetry is received over the beacon channel only. (This means in search tools, the user must select "Beacon" or "Spaceweather" data.) Below is listed the type and number of images scheduled to come down during two hours. Tracks vary in duration, so the actual number coming down each day varies. For the Sidelobe 1 and Sidelobe 2 tracks, the first lower-compression EUVI images and HI images to come down are from midway between the previous and current track. For 34m tracks, there are no images from outside of the current track.
Type | Size | Sidelobe 1 | Sidelobe 2 | 34m |
---|---|---|---|---|
euvi195 (icer10) | 512 | 2 | 4 | 12 |
cor2dbl (icer9) | 256 | 8 | 2 | 8 |
cor1polseq (icer11) | 128 | 3 | 3 | 6 |
hi-1 (icer10) | 256 | 0 | 0 | 1 |
euvi171 | 2048 | 2(icer4) | 1(icer7) | 0 |
euvi284 (icer7) | 2048 | 2 | 1 | 0 |
euvi304 | 2048 | 2(icer4) | 1(icer7) | 0 |
euvi195 (icer5) | 2048 | 2 | 0 | 0 |
euvi195 (icer7) | 2048 | 6 | 1 | 0 |
hi-1 (rice) | 512 | 1 | 0 | 0 |
hi-2 (rice) | 512 | 1 | 0 | 0 |
hi-1 (rice) | 256 | 0 | 1 | 0 |
hi-2 (rice) | 256 | 0 | 1 | 0 |