1. Page 1HMI Team Meeting – January 26-27, 2005 HMI Investigation Overview Philip Scherrer pscherrer@solar.stanford.edu 650-723-1504

2. Page 2HMI Team Meeting – January 26-27, 2005 SDO - Solar Dynamics Observatory HOP HEB SDO will carry: AIA - The Atmospheric Imaging Array Lockheed Martin Solar and Astrophysics Lab EUV – EUV Variability Experiment University of Colorado HMI – Helioseismic and Magnetic Imager Stanford University with LMSAL SDO will be in an inclined geosynchronous orbit with data collected at White Sands NM and operations managed at GSFC.

3. Page 3HMI Team Meeting – January 26-27, 2005 Goals for January 2005 Team Meeting We are now just after the HMI Critical Design Review. The flight instrument is being built and will be ready for optical testing this summer. It will be delivered to NASA for integration onto SDO in November of next year. Proposal was about three years ago and launch about three years away. The data processing center design is near completion. We are near the point where we will need to begin the process of incorporating analysis software. The primary goals for this meeting are to: Update the specifications for standard data products Confirm Co-I plans for analysis software development Encourage coordination in development of science analysis techniques Update the Science Team on the project status Clarify priorities for early science goals

4. Page 4HMI Team Meeting – January 26-27, 2005 HMI Institutional Roles HMI Instrument HMI & AIA JSOC SDO Science LWS Science E/PO Stanford LMSAL The HMI Science Team includes 30 Co-Investigators and many Associate Investigators at 21 institutions in the US and abroad HMI Science Team

5. Page 5HMI Team Meeting – January 26-27, 2005 HMI Science Investigator Team - 1

6. Page 6HMI Team Meeting – January 26-27, 2005 HMI Science Investigator Team - 2

7. Page 7HMI Team Meeting – January 26-27, 2005 SDO/HMI – Stanford Personnel Phil Scherrer HMI Principal Investigator Jesper Schou HMI Instrument Scientist Rock Bush HMI-Stanford Prg. Mgr. Romeo Durscher Admin Sasha Kosovichev HMI Science Lead Phil Scherrer/20** Acting JSOC Data Lead Alan Title AIA Principal Investigator Larry Springer HMI-AIA Prg. Mgr. Jerry Drake Inst. Software Lead LMSAL Barbara Fischer HMI Deputy Prg.Mgr. Jim Lemen JSOC Ops Lead Yang Liu Magnetic Field Science Margie Stehle Admin Support Carl Cimilucca JSOC System Engineer Keh-Cheng Chu JSOC Hardware TBD System Support Jim Aloise JSOC Software Jeneen Sommers Database & GUI Hao Thai Data Operations Rasmus Larsen Processing & Analysis Sebastien Couvidat Sci Prog Support Rick Bogart Data Export Karen Tian VSO Access TBD Sci Programmer

8. Page 8HMI Team Meeting – January 26-27, 2005 HMI Schedule

9. Page 9HMI Team Meeting – January 26-27, 2005 The primary goal of the Helioseismic and Magnetic Imager (HMI) investigation is to study the origin of solar variability and to characterize and understand the Sun’s interior and the various components of magnetic activity. HMI makes measurements of the motion of the solar photosphere to study solar oscillations in order to determine the interior sources and mechanisms of solar variability It also makes measurements of the photospheric magnetic field in order to study how the physical processes inside the Sun are related to surface magnetic field and to enable estimates of the low and far coronal magnetic field for studies of variability in the extended solar atmosphere. Investigation Overview

10. Page 10HMI Team Meeting – January 26-27, 2005 HMI science objectives are grouped into five broad categories: Convection-zone dynamics and the solar dynamo; How does the solar cycle work? Origin and evolution of sunspots, active regions and complexes of activity; What drives the evolution of spots and active regions? Sources and drivers of solar activity and disturbances; How and why is magnetic complexity expressed as activity? Links between the internal processes and dynamics of the corona and heliosphere; What are the large scale links between the important domains? Precursors of solar disturbances for space-weather forecasts. What are the prospects for predictions? These objectives are divided into 18 sub-objectives each of which needs data from multiple HMI data products. Progress requires a science team with experience in multiple disciplines. HMI Science Objectives – Top Level

11. Page 11HMI Team Meeting – January 26-27, 2005 A.Sound speed variations relative to a standard solar model. B.Solar cycle variations in the sub-photospheric rotation rate. C.Solar meridional circulation and differential rotation. D.Sunspots and plage contribute to solar irradiance variation. E.MHD model of the magnetic structure of the corona. F.Synoptic map of the subsurface flows at a depth of 7 Mm. G.EIT image and magnetic field lines computed from the photospheric field. H.Active regions on the far side of the sun detected with helioseismology. I.Vector field image showing the magnetic connectivity in sunspots. J.Sound speed variations and flows in an emerging active region. B – Rotation Variations C – Global Circulation D – Irradiance Sources H – Far-side Imaging F – Solar Subsurface Weather E – Coronal Magnetic Field I – Magnetic Connectivity J – Subsurface flows G – Magnetic Fields A – Interior Structure HMI Data Product Examples

12. Page 12HMI Team Meeting – January 26-27, 2005 Version 1.0 HMI Data Products and Objectives

13. Page 13HMI Team Meeting – January 26-27, 2005 HMI-AIA Joint Science Operations Center HMI and AIA SOCs have been merged to form a JSOC Components of the JSOC will be at both Stanford and Lockheed-Martin Solar and Astrophysics Lab (LMSAL) –JSOC-Ops for both HMI and AIA at LMSAL –Data capture, pipeline processing, online archive, tape archive, export functions at Stanford. –HMI Higher level processing at Stanford –AIA Higher level processing at LMSAL –High-speed network connection between the two sites The JSOC will be discussed in more detail as part of both the SDO CDR and the SDO ground system CDR next year

14. Page 14HMI Team Meeting – January 26-27, 2005 HMI & AIA JSOC Architecture Science Team Forecast Centers EPO Public Catalog Primary Archive HMI & AIA Operations House- keeping Database MOC DDS Redundant Data Capture System 30-Day Archive Offsite Archiv e Offline Archiv e HMI-AIA JSOC Pipeline Processing System Data Export & Web Service Stanford LMSAL High-Level Data Import AIA Analysis System Local Archive Quicklook Viewing housekeeping GSFC White Sands World

15. Page 15HMI Team Meeting – January 26-27, 2005 Schematic Diagram of HMI Telescope with polarization analysis Tunable narrow band filter Camera system SDO MOC DDS Computers Electronics to make it work Science Investigation Science Team, NASA, Taxpayers

16. Page 16HMI Team Meeting – January 26-27, 2005 Measure Here HMI consists of a telescope, tunable filter, camera, and necessary electronics. HMI repeatedly images the Sun in six polarizations at five wavelengths across a spectral line. The position of the line tells us the velocity while the shape changes of the line in different polarizations tell us the magnetic field direction and strength in the part of the Sun’s surface seen by each pixel. Long gap-free sequences of velocity images are needed to enable the techniques of helioseismology. HMI – How It Works

17. Page 17HMI Team Meeting – January 26-27, 2005 The green and red curves are Left and Right circular polarized components and allow measurement of the line-of-sight projection of the field. Analysis of both polarizations is required to infer the Doppler velocity and line- of-sight magnetic flux. For vector magnetic fields two directions of linear polarization are added to infer the field direction. One HMI camera is used for velocity and LOS field, the other for vector fields. Magnetic Field Sample Profile HMI measures magnetic fields by sampling the Zeeman split line in multiple polarizations. The figure shows the five sample positions for a sunspot umbral field (about 3000G) with a 1000 m/s offset.

18. Page 18HMI Team Meeting – January 26-27, 2005 Basic Requirements Sources SDO Level 1 Requirements SDO Mission Requirements Document (MRD) –Summary of spacecraft and instrument driving requirements HMI Instrument Functional Specification –Top level instrument requirements – part of the HMI contract statement of work HMI Instrument Performance Document (IPD) –Detailed HMI science drivers and flowdown to subsystem requirements HMI Performance Assurance and Implementation Plan (PAIP) –HMI implementation of the SDO Mission Assurance Requirements HMI to Spacecraft Interface Control Documents (HMI-S/C ICD) Ground System Interface Control Documents

19. Page 19HMI Team Meeting – January 26-27, 2005 HMI “Level 1” Requirements To enable accomplishment of the science objectives of the investigation, the HMI instrument will produce measurements in the form of filtergrams in a set of polarizations and spectral line positions at a regular cadence for the duration of the mission that meet these basic requirements: Full-disk Doppler velocity and line-of-sight magnetic flux images with 1 arc-sec resolution at least every 50 seconds. Full-disk vector magnetic images of the solar magnetic field with 1 arc-sec resolution at least every 10 minutes. The HMI data completeness and continuity requirement is to capture 99% of the HMI science observables 95% of the time.

20. Page 20HMI Team Meeting – January 26-27, 2005 Source of HMI Requirements HMI Science Objectives –Duration of mission –Completeness of coverage –HMI Science Data Products –Roll accuracy –Time accuracy (months) HMI Observation Sequences –Duration of sequence –Cadence –Completeness data sequence –Noise –Resolution –Time accuracy (days) HMI Observables –Sensitivity –Linearity –Acceptable measurement noise –Image stability –Time rate (minutes) –Orbit knowledge HMI Instrument Data –Accuracy –Noise levels –Completeness of filtergrams –Tuning & shutter repeatability –Wavelength knowledge –Image registration –Image orientation jitter HMI Instrument –Mass –Power –Telemetry –Envelope Subsystem requirements –CCD: Thermal environment –ISS: pointing drift rate, jitter –Legs: pointing drift range

21. Page 21HMI Team Meeting – January 26-27, 2005 HMI Performance Requirements Summary