1. Instrument Performance Spefication 13 July 2001 SECCHI Consortium Meeting Cosner’s House, Abington Dan Moses

2. Instrument Performance Specification The IPS demonstrates the flow down of the instrument specifications (and resulting requirements) from the SECCHI science objectives. The SECCHI instrument specifications can be described relative to those of the SOHO LASCO/EIT. –The current CME paradigm is derived from SOHO. – LASCO/EIT is the current state of the art in CME observations and forms the technological basis for SECCHI.

3. STEREO SECCHI Science Objectives There are three listings of the Science Objectives: –The June 2001 STEREO Pre-Confirmation Review Level 1 Science Objectives presentation (Joseph M. Davila/Lika Guhathakurta). –The February 2001 STEREO De-scope Plan Science Requirements Presentation (Joseph M. Davila/Lika Guhathakurta). –The August 2000 SECCHI Phase A Concept Study Report (SECCHI Consortium).

4. June 4, 2001 Haydee Maldonado - STEREO Project Manager Solar Terrestrial Relations Observatory (STEREO) Pre-Confirmation Review Delta

5. STEREO Level 1 Science Joseph M. Davila/Lika Guhathakurta

6. Science Objective CME initiation 3D CME propagation Energetic particle acceleration Ambient solar wind structure

7. Organizational Approach Consider observational opportunities unique to STEREO - Stereo viewing by remote sensing suite: two views of the same source from different positions - Multipoint in-situ observations: two observations from different positions within a single event Coronagraph stereo viewing requirement divides mission into 3 roughly equal phases

8. Stereo Imaging with Two Coronagraphs No overlap in FOV at intermediate separation angles Overlapping FOV exists at small angles, and large separation angles Corona seen by coronagraph B Corona seen by coronagraph A Polar View

9. Mission Phases

10. Mission Observational Capabilities STEREO-A at quadrature with STEREO-B Multipoint observation of Earth directed CMEs In-Situ Stereo view of plane of sky CMEs and their propagation Stereo Science Remote SensingPhase View of Earth directed CMEs LWS Precursor Science Halo and limb CMEs and their propagation Multipoint Science

11. Level 1 Science Statement Must have 80% of the in-situ and 80% of the remote sensing instruments operating on each spacecraft for the first 150 days after reaching heliocentric orbit And 80% of the in-situ and 80% of the remote sensing instruments operating on one spacecraft for the remainder of the 2 year mission Heliocentric orbit is reached approximately 90 days after launch 150 day period will allow the observation of up to 100 events at solar

12. Level –1 STEREO Science Requirements From: “Prioritized STEREO mission science objectives”, J. Davila (STEREO Program Scientist) February 2001.

15. Instrument Performance Requirements Note: Improvements in the supporting photospheric magnetic field measurements (higher sensitivity, higher spatial resolution and vector measurements) would increase the level of success in Objectives III &IV.

16. Challenges Compared to SOHO Range of Field of View –Requires 4 separate instruments in Visible regime –Requires improved polarization measurement Image Cadence –Requires higher image throughput CCD Camera Readout Rate Image Processing Rate (Software and CPU Challenge) Telemetry Interface Ground System Challenge 3 Dimensional Analysis –Two instrument suites –Absolute timing requirement –Other requirements not yet specified??? STEREO Spacecraft Accommodation –Pointing control –Jitter compensation –Telemetry interface

17. Concept Study Report Traceability Matrix

18. Updated Instrument Parameter Table