General description


The prime objective of the ‘full disc mosaic’ observation campaign is to facilitate cross-calibration activities with Earth-based assets. This cross-calibration is relatively straight-forward for full disc telescopes such as PHI/FDT and EUI/FSI as each image can be directly compared with the best equivalent on Earth-based satellites, viz. SDO/HMI and SDO/AIA.

The secondary objective of the ‘full disc mosaic’ campaign is outreach & public relations, comparable perhaps to the ‘Mars panoramas’ produced by NASA Mars rover cameras [2]. The produced mosaic will be the highest resolution images of the full disc ever allowing very deep ‘zooming in’ movies. The combination of PHI, EUI, and in particular SPICE, will illustrate the changes in morphology of the solar atmosphere as one scans from lower to higher plasma temperature. Also for this secondary objective, 100% coverage of the full disc is ideal, but not absolutely required. For outreach purposes, small gaps in the coverage between the mosaic tiles can be processed away or left purposely in to illustrate the mosaicing.

The following hard constraints apply:

  1. Slew time for the spacecraft to move from 1 position to the next is 5 min, irrespective of the starting and ending position

  2. Dwell time at each position should be as short as possible but needs to be at least 1 min for EUI, 1.5 min for PHI and at least 5 min for SPICE. To accommodate all 3 instruments In the March 2022 conjunction, we will take a dwell time of 5 min but the dwell time could be different in future repetitions of the campaign.

Pointing requirements:

  1. The time difference between adjacent tiles should not be larger than 1 hour in order for solar evolution to remain sufficiently small such that stichting is possible.

  2. We want the mosaic to cover up to 0.08 Rsun above the solar limb with EUI/HRIEUV

  3. SPICE should see the limb in all directions.

The mosaic need to include pointings at least 0.90 Rsun away from the disc center in each direction.

Default SOOP duration: 4h10mn

Observations requirement (baseline)

Mosaic dimensions: 5x5: 

The number of tiles needed in the mosaic to cover the full disc is in principle a function of distance to the Sun. In order to limit the difference in time of observations between the different tiles, proposal is to stick to a 5x5 mosaic.





SPICE will use either a sparse raster or slot image (30” slit). The details of the observations are still to be defined. A possible sparse raster could be:

  •  6” slit
  • 768” Y-FOV (12.8’)

  • 8s exposure time

  • 32 steps or 24”, for a total X-FOV of 744” (12.4’), making a 1⁄4 sparse raster.

  • Total duration: 295s. Not including 20s overhead which would have to be during the last

    20 seconds of the previous slew.

    With this raster, the coverage would not be continuous with 25 tiles. This is however not critical and acceptable for the cross-calibration of SPICE.
    Using the wide slit (30”) would bring the Y-FOV to 14.9’ and would thus allow for better spatial coverage. Usage of the wide slit for this mosaic still has to be investigated in detail.

All pointings will be wrt SC+X as the boresight


EUI HRIEUV can be figured with an extended FOV which will help maximising overlap and imaging the off-limb area. This is unfortunately not the case for EUI HRILYA.

All pointings will be wrt SC+X as the boresight


PHI science mode 2 (FDT); burst mode triggered by STIX to catch white light flare in high cadence

All pointings will be wrt SC+X as the boresight

Science objectives

SAP objectiveTargetDurationOpportunity
(e.g., orbital requirements, solar cycle phase, quadrature ...)

Operational constraints 

Additional comments

Instances run / planned, differences from the baseline observations

LTP06 (run):

7 March 2022 (SOOP coordinators: D. Berghmans)

EUI/HRIEUV:   successful
EUI/HRILYA:    successful but remnants
SPICE:             successful but corners
PHI/HRT:         no data due to internal problem

LTP09 (planned, not run):
2022-11-06 (SOOP coordinators: D. Berghmans)
fully failed due to SSMM issue

LTP11 (planned):
2023-03-22 (distance =0.491 au) (SOOP coordinators: D. Berghmans)

Science outcomes

Ref of paper using the SOOP data

Original SOOP proposers

David Berghmans, Frédéric Auchère

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  1. SOOP ID in SOOP Kitchen is RSD